# 2x72 sander



## ShawnR (Mar 8, 2021)

Coming up the list is to build a 2x72 sander. I attached a poll here just for fun and curiosity as it seems like this is a popular project for home hobbyists. A friend approached me a couple of months back with some questions and, since then, I have spent too much time spinning my wheels on it, so it is time to move forward. on building one.  I was hoping we could design one together and then post the plans in the "Plans" section. As those that have been on committees before, the more people involved,the longer a project takes but at least we will all have some input. There are tons of videos and plans available on line. For me, here are my thoughts and options. You might be in a slightly different, or very similar situation.
I don't have square tubing that slides nicely into other square tubing, which seems to be a common thread with plans on line.
I do have lots of round tubing/pipe/DOM tubing and I have a metal lathe that works better with round stuff than square stuff
I have scrapped a couple of treadmills and have the motors and controls boards (read variable speed, 2-3 hp ) 
These sanders have been mentioned several times for sharpening tool bits...right up our alley
I think the round pipe lends itself to a tilting sander better/more easily done than with square tubing (but that mechanism does not look too difficult either)
So, rather than post pics after it is done, I thought I would see what the group has to say. And wondering if there is interest in making this a group project. I lack CAD skills but am trying so won't even post what I have so far. but eventually, plans will need to be drawn to post in that forum. Mine will be awful, functional, but awful....just saying!

For now, start with the poll. I would be interested in seeing who has built one and if they used plans, which plans. or just winged it. I would guess "winged it", from this group, is going to be the answer.


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## Brent H (Mar 8, 2021)

@ShawnR - I have plans for one built up out of 1/2” plate sheet - will post as soon as I can.  It is one off of a knife makers ideas and a basic smash up of several other “machines”, Plans and ideas.   It is laid out as a bolt together but I would slot weld it or full weld - will be heavy.


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## ShawnR (Mar 8, 2021)

@Brent H ...I have seen some bolt ups. My friend showed me the plans he has but not sure if he bought them so I won't mention where they are from or repost them. They look good and well done, but I think a rather large amount of work for something we can do more easily with round stock, of some sort. Again, looking at my stock and looking for a sander in it. The more I look,the easier they look to build. Some plans are really simple and I think that is the way to go, then I see other Gucci plans and think, that is pretty sweet so it comes down to what the builder wants and has access to. Maybe not a good project for a group like this cause there is such a diversity in stock items, (if that was a building criteria) but I thought if some have built one, maybe they would add their likes and dislikes about the project. 

So far, I think the tilting feature of the sanding belt is really appealing, as is the ability to tilt the table sharply down. This is a knife makers need for the sharpening/shaping profile, I guess. Also, I could see a benefit to swapping out a flat grinding surface for a wheel so you can do inside radiuses. (radii?) 

Lots of good ideas out there. The more I look, the more I want one. My focus will be on using a treadmill motor and control board for the drive so hopefully, that helps others with the drive system. Some guys are buying 3 phase motors and putting VFD's on them. Cool, but to me, it is just a belt sander. I would put that motor on my lathe instead, given the option. or drill press.....just saying..

But in the end, we can post a plan, in our forum,  that we did not take from the internet and is a collaboration of member's inputs. Cool, I think.


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## Janger (Mar 8, 2021)

You go Shawn ! That’s a great idea.


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## ShawnR (Mar 8, 2021)

So, to get the discussion going, here is what I am starting with. ....the pulley (more like a flywheel) on the motor is about 5 3/4" in diameter and about 1" wide. The grooves you see are for a micro v belt. So, to me, the wheel is too narrow to be a direct drive pulley, and I would like a larger diameter to increase surface feet per minute. Most knife makers ( correlating to efficency) seems to be about 5000 sfpm. I would like to keep the RPM in a reasonable range, although not sure what that is yet for these motors. Having said that, I have not tested the motor to see what it actually like to run at. But  I had a 7 inch diameter in mind ..about 2700 RPM. I would start with anything from the existing diameter to a custom made 7 incher (when stock avails itself to me. )
The thread holding the flywheel on is a 1/2" left hand so easy enough to make a whole new drive pulley. Casting one? Making one out of pipe and plate? Modifying the flywheel? I have seen plans for shop built stuff before using MDF as the pulley. On a machinist's forum, this would be frowned upon but practically speaking, to bond a piece or two of MDF to the existing fly wheel  to have a 2" wide drive pulley,with the cast iron flywheel as the base ...... might actually work....

Mounting the motor...I don't like the existing mounting brackey but would reuse the holes in the motor chassis.

I would put a tach on it but one that displays SFPM instead of RPM. Couple ways to do this, Microcontroller (Arduino) to do the math and display it or a pulley sized so that the RPM reflects the SFPM ie if the circumference of the sensing pulley is ten inches, then SFPM is 10 times the tach display or add magnets as multipliers.

I have 4 scrapped treadmills and 3 complete controllers/motors. One motor where the controller was pooched. So saying, if you want to do this and have not looked into Treadmills as resources, it might interest you.

Cheers,
Shawn


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## Tom O (Mar 8, 2021)

You could always weld/braze 3/8x1/8 strips on the inside sliding tube and machine for fit that way the seam isn’t a problem.


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## 6.5 Fan (Mar 9, 2021)

I will be watching this thread closely, always wanted one but to many other projects.


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## ShawnR (Mar 9, 2021)

Tom O said:


> You could always weld/braze 3/8x1/8 strips on the inside sliding tube and machine for fit that way the seam isn’t a problem.



Yes, I have done that in the past. Or groove the inner piece to slide around the seam. There is also a guy online that suggests a block of wood or aluminum to guide a grinder or cutter through the inside to remove the seam. All great options. I was just looking at my stock and thinking do something different and with what I have, and an excuse to use the lathe, somewhere in there. It is more of a "lets do something different" rather than just get it done project.  (This time..... )

Thanks
Cheers,


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## Dabbler (Mar 9, 2021)

Not worth the effort to avoid the seam.  just remove it.


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## Tom O (Mar 9, 2021)

I’ve seen that before as well as the tool bit being pulled through by threaded rod this will have to go on the to do list I think I have some square stock that size.


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## John Conroy (Mar 9, 2021)

It would be fairly easy to duplicate that "Seams Impossible Tool" or you could go the Jeremy Schmidt route and make tubing from flat bar.

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## ShawnR (Mar 10, 2021)

John Conroy said:


> It would be fairly easy to duplicate that "Seams Impossible Tool" or you could go the Jeremy Schmidt route and make tubing from flat bar.


I think that was the first video I watched on these things. He did do a nice job but I think a harder way to go than finding materials that work together without the welding.

@Dabbler , that is not the same guy I saw but same idea. Looks like he has put together a nice tool. Thanks


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## ShawnR (Mar 10, 2021)

A friend dropped off some 6" pipe yesterday. My thought is to make it fit over the existing flywheel from the treadmill.  Cutting a 2" (2.25") wide band, then making it a press fit onto the flywheel would be an easy conversion I think....not sure if I have the skill set to make a concentric, press fit, secure modified wheel, but I have about 6 feet of pipe to learn with. 

Please insert suggestions but here is my plan

Load flywheel in lathe, making it turn as true as possible (I don't have a 1/2" left hand mandrel for centre thread) and turn small micro belt hub down to a smooth surface (to be used a mandrel later)
Turn it around and mill outer edge, just cleaning it up
Remove and install 6 pipe into lathe and clean up inside, turn to press fit dimension for flywheel. When there, remove and install pipe onto flywheel
Reinstall assembly into lathe, held by centre mandrel and true up outer edge for belt surface. 

Does that sound about right? Not sure if there is a better way to do it, ie, turn pipe first, then fly wheel? Maybe turning outside of fly wheel is easier than boring inside of pipe so mill pipe first?

What do you think?


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## RobinHood (Mar 10, 2021)

I think your procedure should work.

One thing: it is easy to distort the pipe. If you cut off say a 2.25” wide ring and clamp it in either the 3J or the 4J for ID turning, you will most likely end up with either a 3 or 4 lobed “ellipse“ of an ID when you release it from the chuck. Then it won’t press fit properly onto the flywheel.

Depending on the wall thickness of your pipe, it might be a good idea to weld in temporary cross supports and use the 4J on the supported spots. Cut your ring about 4-6” wide so that you can machine the bore of the first 2.25”. Once you have the ID to where you want it, part off the 2+” ring you need (the “+” part being for machining allowance once the ring is pressed on the flywheel to true up the sides).

It is tempting to just cut a ring of 4-6” wide and grab it in the chuck - thinking that one can just machine the “free” first 2” or so. Bad things can/will happen fast (the speed at which these bad things happen depends on the distortion of the pipe wall): the ring will walk right out of the chuck jaws. The harder you chuck it up, the faster it comes out.

Joe Pie has a two part video showing the distortion I am talking about (and how to fix it)


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## ShawnR (Mar 10, 2021)

Thanks Robin. I just finished the flywheel when I saw this. Your timing is perfect. Good points. I will check out Joe's vids and reassess and report back. At least with 6 feet of pipe, I have a few cracks at it...


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## Crosche (Mar 10, 2021)

Here is a YouTube video from Fireball Tooling on how he removes welding seams:






Also, I would like to mention that you will need to crown both your drive wheel and tracking wheel or you may have a hard time keeping your belts on. You are welcome to take a look at my 2x72 if you like; it has some great features and some mistakes to be learned from.

Good luck with your project. 

Cheers,

Chad


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## PeterT (Mar 10, 2021)

Maybe another way around the tubing sleeve issue vs dealing with weld seam & rounded corners & potentially sloppy sliding fit is - Just make your internal bar however it turns out, like maybe you want to flycut it smooth so its going to be an oddball dimension anyway. Then make the socket from 4 slabs of metal with whatever clearance you prefer. Could be bolted or welded or whatever. Depending on the design I don't think there is a requirement that the bar as to be square section or the external socket edges even flush. I think its more about the nice sliding fit & lock mechanism.


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## Dabbler (Mar 10, 2021)

@Crosche can you measure the crown on  both wheels and post?  it would help the design...


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## Crosche (Mar 10, 2021)

Dabbler said:


> @Crosche can you measure the crown on  both wheels and post?  it would help the design...



Yes, I will measure them and post the dimensions.


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## Tom O (Mar 10, 2021)

I would think it would be between 1/16 and 1/8” crown, at work we just built up the roller with masking tape till it centered on the conveyors.
You could put it together and build up the surface to see what you need for a crown and machine them last.


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## ShawnR (Mar 10, 2021)

Well, this is the largest project I have taken on with my lathe. Did I mention I might want a larger lathe...? 

Worked through the steps I outlined above. My lathe is a 10" but these 6 inch pieces, with my chuck, max out the jaws. Apparently, my measuring tools too as I only go up to 6" vernier calipers so making a press fit might be more "guessetimate" than measurement.... I don't think you have a lot of trial and error room in press fitting.

Turning the grooves off the hub was easy. The hub is cast iron but machines nice. Cleaner than some cast I have worked with.  I just cleaned up the rim as I don't know how far I will need to go till I get the pipe cleaned up. That in itself is taxing me. Probably mostly lack of experience on my part, but there are also machine limitations in the equation.  @RobinHood gave me some concerns to watch for and I tried to be wary of it but not sure my little chuck would be bending the pipe with .258 walls. All the same, I figured good to be careful. Before  I started, I used a grinder to clean the majority of the rust off of the inside and outside of the pipe, but in doing this, I then found it hard to get a perfect alignment in the chuck because of the variations in the surface caused by the grinder. I think if I were to start over, I would do it slightly differently. Near the end, (ie when I had it almost one clean inner surface, I noticed chatter so I switched to a heavier boring bar with a HSS bit in it and it cut nicer than the carbide boring tool I used for most of the cutting. I should have done it all with the heavier bar but it has a longer overhang at the end so can't get all the way in. And I was thinking that the rusty inside would beat up the HSS more than the carbide  All good experience. though Still working on it. Found out that my cross slide does not fit under the pipe in the lathe so need a long tool to cut the outer surface. I think I will be using the boring bar on the outer surface just for reach.

From the pic of the back of the hub, you can see what I have to work with for material thickness on the edge, which will be press into the pipe to form the drive hub I think there is lots of material there if I can match a maximum pipe thickness with minimal removed from the hub. Will know more when I get the pipe to good inside and outside surfaces. The hub is good to go now, I think, so anything from here on it is just to get the fit I need.


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## ShawnR (Mar 10, 2021)

Crosche said:


> Also, I would like to mention that you will need to crown both your drive wheel and tracking wheel or you may have a hard time keeping your belts on. You are welcome to take a look at my 2x72 if you like; it has some great features and some mistakes to be learned from.
> 
> Good luck with your project.
> 
> ...



Chad, I read somewhere that you should only crown one pulley, the guide one. So you found that you needed two crowned? Good to know.


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## Crosche (Mar 10, 2021)

ShawnR said:


> Chad, I read somewhere that you should only crown one pulley, the guide one. So you found that you needed two crowned? Good to know.



Yes, both my drive and tracking pulleys are crowned; I tried running a machine with only a crowned tracking pulley and couldn't keep the belt on it. My drive pulley measures 4.70" outside diameter and 4.96" middle diameter and it is 2.25" wide with a 5/8" bore. If I calculated correctly, the crown taper is just over 6.5 degrees.
Also, be very aware of the distanced between your drive pulley, tracking pulley and the wheels on your tooling arms which will vary due to the size and type of wheel or platen. I am worried that with such a large drive pulley you are going to use a lot of belt length and really limit the size of contact wheels your grinder will accommodate. My machine only has a 5" drive wheel and I find getting some contact wheels to fit is a challenge. 

If you are not heavily invested in making a drive pulley, my friend has a 4" drive wheel from his 2x72 which he said he would sell for $25.


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## ShawnR (Mar 11, 2021)

Crosche said:


> Yes, both my drive and tracking pulleys are crowned; I tried running a machine with only a crowned tracking pulley and couldn't keep the belt on it. My drive pulley measures 4.70" outside diameter and 4.96" middle diameter and it is 2.25" wide with a 5/8" bore. If I calculated correctly, the crown taper is just over 6.5 degrees.
> Also, be very aware of the distanced between your drive pulley, tracking pulley and the wheels on your tooling arms which will vary due to the size and type of wheel or platen. I am worried that with such a large drive pulley you are going to use a lot of belt length and really limit the size of contact wheels your grinder will accommodate. My machine only has a 5" drive wheel and I find getting some contact wheels to fit is a challenge.
> 
> If you are not heavily invested in making a drive pulley, my friend has a 4" drive wheel from his 2x72 which he said he would sell for $25.



Good to know about the crowning of two.

When you say contact wheels, do you mean when the sander is configured for working with one pulley, versus a flat platen? Or the wheels in the general construction? I have been thinking I should take a rope and lay out some stuff to get an idea of dimensions. I like compact but not non functional. You make a good point.  I don't have a belt yet for sizing. Could get one today probably in town, I think.... Couple of places I checked have none though.  I will hold off on buying the pulley from your friend, Thanks for the offer. Most of this stuff I do is to learn how to do it, as much as that is a battle sometimes,...... 

I finished a melting furnace recently and it is pretty much ready to start melting aluminum so I could cast one that size easy enough. A larger one, like this size, was going to be the limit of my crucible and.....I have not melted anything yet..... so that will be another learning curve I have been avoiding while I am figuring this other stuff out. I plan on casting the other pulleys. They will just start out looking like a soup can, I think. They look easy enough.  I was  trying to keep the motor speed down, ie larger drive pulley, but have not tested the motor to see what it can do for RPM. Any idea what your motor spins at? What type of motor did you use? I figured my chassis design will hinge around the drive pulley and platten so will see how this drive pulley turns out. How long is your platten?

Can you post a couple photos of your sander please?

Thanks
Cheers,


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## Crosche (Mar 11, 2021)

ShawnR said:


> Good to know about the crowning of two.
> 
> When you say contact wheels, do you mean when the sander is configured for working with one pulley, versus a flat platen? Or the wheels in the general construction? I have been thinking I should take a rope and lay out some stuff to get an idea of dimensions. I like compact but not non functional. You make a good point.  I don't have a belt yet for sizing. Could get one today probably in town, I think.... Couple of places I checked have none though.  I will hold off on buying the pulley from your friend, Thanks for the offer. Most of this stuff I do is to learn how to do it, as much as that is a battle sometimes,......
> 
> ...



I will post photos of my machine tonight. You are welcome to have one of my worn out belts for sizing purposes. 
By contact wheels, I am referring to the surfaces or wheels that you grind with, the ones that come into contact with your work. The great thing about a 2x72 is that the front wheels can be changed out very quickly to accommodate different diameters of contact wheels and different sizes and shapes of platens. Many 2x72 grinders can accommodate 12" diameter contact wheels all the way down to 1" contact wheels and 7"~9" platens.


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## ShawnR (Mar 11, 2021)

Thanks for the belt offer but if not available locally, I will order. I have been building an order with KBC and will finally place it when I need something in particular like the belt. Thanks for clarifying the "contact ". I figured that but did not want to assume. As of right now, I am only planning a flat platen but will keep wheel size in mind when I start working on the chassis. Having a good day so far cleaning up the rim. I am optimistic we will be successful......


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## Tom O (Mar 11, 2021)

I use a 6x6x9” square tubing for a crucible for casting aluminum and a clay graphite for brass. I have bolts in the two corners for lifting lugs. The pic below shows my unconventional tongs ( the lifting tabs were not welded yet ) the lower plate of the crucible has a eye on the corner for pouring.  The lifting tabs are placed over the bolts and by gripping the handle/lever keeps pressure on the crucible so there is no slippage and since you are picking it up from the corners you have a built in pouring spout I use a coat hanger through the baseplate eye to pour. With this design you could even lift by the lower handle while keeping the grip on the crucible.


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## ShawnR (Mar 11, 2021)

Thanks Tom. I built a similar crucible for lead several years ago but made the mistake of putting the lifting eyes on the sides, which of course, made pouring difficult. It will be easy enough to fix when I get to that stage. Obsessed with getting this drive wheel assembled right now. Having said that, do you have any photos of the sieve you use to clean out the molten aluminum? I will need to get/make that before melting anything.


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## Tom O (Mar 11, 2021)

The only sieve I use is for the sand during mold making the dross is just scooped off the top.


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## molyknow (Mar 11, 2021)

Would it make sense to start a collaborative fusion file for a site designed grinder?


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## Crosche (Mar 11, 2021)

molyknow said:


> Would it make sense to start a collaborative fusion file for a site designed grinder?



Great idea. Many YouTube videos don't show a lot of the finer details that go into grinder builds.


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## ShawnR (Mar 11, 2021)

molyknow said:


> Would it make sense to start a collaborative fusion file for a site designed grinder?



That would be great! I wanted to suggest that when I started this thread but I cannot contribute to it so I didn't.  I am still trying to figure out how to draw a piece of square tubing in a CAD it. (and I moved to FreeCAD ). And then to draw two pieces and somehow connect them......nope.... so I will just be the test dummy. Thanks Alex!


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## ShawnR (Mar 11, 2021)

I am thinking this is not the most efficient way to come up with a drive pulley....  Might have to fire up that furnace sooner than I thought, but learning lots about setting up. Spent most of the day cleaning up the pipe flange while trying to ensure that the flange is concentric. Got there ...close enough, I think but now need to fit it to the flywheel. I may need to borrow a 12" caliper from a friend or take it to another friend to finish it. I don't want to just throw the flywheel in the lathe and start turning it down cause I think I might botch it. Would be nice to have some numbers to shoot for. Here are some photos of todays activities.

Because of the cross slide hitting the flange, needed to use the boring bar for reach
Found that a shop vac works great to clear the smoke ...personal localized exhaust system
I spent way too much time swapping flange back and forth trying to maintain/fix concentricity. Has to be an easier way....?
But got it close. Need to remove about 0.160 " total from flywheel diameter to press flange on. Thinking this is better than thinning the flange, which sits about 0.230"
Last pic is that of a piece of stock I have. I believe it was purchased as plastic bearing material. I am thinking it might work as the other wheels. Is anyone familiar with it? I got it from a hydraulic shop many years ago when I built the backhoe. I think, if I recall correctly, it was supposed to be good stuff. I could turn an axle and be done? Input? I guess if it does not work, I could then make the wheels from aluminum. Just a thought. I found this link. I wonder if the GGG is supposed to be a GGB    https://www.ggbearings.com/en/our-products/engineered-plastics-bearings


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## ShawnR (Mar 12, 2021)

I was surfing around today, looking for more ideas, etc. I found a video of someone
who made a sander from a treadmill motor....so much for being original on my part  

I should have known that if you have an idea, chances are that it has been done, and is on youtube somewhere.  So plunging forward, this is my disclaimer. I wanted this to be a group project, and still can be but will probably be a collection of ideas from the internet. There are countless ways to get it done. I had originally suggested using round stock for the main structure, my reasoning being a nice solid pivot point but looking at my stock, might be, begrudgingly, reverting to square stock....only because it has been done so much, I wanted to be different! Oh well. If it works, ....

@molyknow if you are interested in doing CAD drawings, let me know what you need as I step through the prototype. I can supply numbers as I go, if you or anyone with CAD skills would like. It would be nice to end up with nice drawings added to the Plans section. Not sure me being the lead designer/prototyper is our teams best choice....but I will take the hit for the team..

Some notes.. I like this design linked below, basically, so might build on it....  And he is not selling plans or anything so I don't feel bad about using it to get started.

I noticed in the video below, he does not change the width of the drive pulley, but rather just loops the belt around it as is. The pulley is about 1 " wide. I forget exactly. What is your take on this? Worth widening the drive pulley to  the full belt width? I would think that a narrower pulley will accelerate wear on the belt as it flexes and stretches around it so I think I still like the idea of a full width drive pulley. But, what do you think? As I read through this again, looking for errors, I thought that the natural narrowing of the drive pulley almost imparts a crown in the drive belt....mmmmm...

His platen does not rotate and that was a mandatory option for me, so I will incorporate that somehow, round pipe or hinges.

His motor mount, cut from his treadmill, is more solid than the ones I am finding but his is what I pictured. So, mine will end up being similar, just shop made.

He uses an aftermarket speed controller. I got mine out of the treadmills I scrapped. That will be the last thing I work on. If anyone has any questions about this aspect, post your questions. I am sure others here have more experience than me.

So, back to the saga of the drive pulley flange.

Cheers,


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## ShawnR (Mar 12, 2021)

And here is a link to the electronics end of things. He stated the motor can go up to 7900 RPM so I guess my concerns about RPM were for not. A smaller drive pulley will be fine.


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## Crosche (Mar 12, 2021)

Pics of my grinder w/ small wheel attachment.


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## ShawnR (Mar 13, 2021)

Thanks Chad. That is a solid looking sander! I may be under designing mine. Seeing your single wheel gives me an idea. I have been only picturing a flat platen this far, but perhaps could incorporate the option that the flat platen turned on end becomes a single wheel. I think in the Jeremy design, linked above, he suggests other fixtures, ie, a single wheel. Gives me more to think about.

A friend dropped by with 8" Verniers yesterday and so I could continue my fitting of the flange to the hub. He also mentioned/reminded me that the pipe will expand quite a bit with heat. I was planning on mating them with temperature differential anyways but that gave me more room to play with. I turned the hub to only within about .010 as a start. I then used a propane torch on the flange (to about 80C?) and a snowbank for the hub. I slid it on part way, and it stopped. So I went to Acetylene. checking temp with a heat gun as I went, trying to keep it even. I was able to get the hub out, do it again, but heated the flange to about 180C this time, with the hub back in the snow bank. I used 3/4" tool bars in the flange to set the height and upon assembly, the hub dropped in! I will check the balance today and do a final truing up, I hope and then move on to the chassis.

For anyone reading this as a "how to", this flange episode might be a "how not to" but what the heck, having fun. Running the sander at the end will be the final test as to whether this is a reasonable alternative to getting a solid aluminum drive wheel. With this 6.25 inch OD wheel, my motor will be running about 3000 RPM for a 5000 SFPM belt speed, which I have read is the desirable surface speed for knife makers. @Crosche correct? That puts the motor about mid range, if the info that 7900 rpm is the max for these motors, so I feel good about that.

Also, a 3200 (3250?) RPM motor is fairly common, so this size drive wheel opens up options if variable speed was not a requirement in your design.

Cheers,


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## Crosche (Mar 13, 2021)

@ShawnR you are correct about the surface speed; however I don't think drive wheel temperature will be an issue. Even after a long grinding session you can still touch the drive wheel on my grinder with bare hands and considering that your drive wheel is much bigger and has more mass this should be even less of a problem for you. The greater concern, I think, will be dynamically balancing the drive wheel so it doesn't shake everything off of your bench. 

Also, please note the location of my drive wheel; it is too far away from the chassis and thus makes it difficult for me to change belts and contact wheels. Realistically the driver wheel should be at least 2"~3" closer to the chassis to extend the range of travel of the tooling arms and give me more belt to work with. This is a major challenge when we design a machine for the group because of the different motor configurations and drive wheels that people may use. Our design will have to make provision for mounting all types of motors.

Cheers,

Chad


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## RobinHood (Mar 13, 2021)

Looks like you are making good progress. Nice looking drive wheel. Good “rescue” of the stuck steel tire off the hub. Yes, pipe does expand a lot.

Please don’t take this the wrong way, as nothing happened this time, but be very careful and aware of how far the jaws are sticking out while machining.

There was not much thread engagement in your set-up. Rule of thumb is jaws don’t go past the edge of the chuck by more than 1/3 the length of the jaw, to ensure 2/3 to no less than 1/2 length engagement. Look at your pictures: I would be surprised if you had more than two threads hanging on.











The threads on the pinion do not start right at the end, neither do they on the chuck jaw. You may want to mark a “no go zone” beyond which you should not extend jaws.

Here is what TMX recommends for safe practice (I just picked a manufacturer, not affiliated. You can search for others, info is more or less the same for all of them).






I’ve had a 4” PVC pipe come out of a 4J at 1000 rpm. I was doing ID work and luckily the piece caught on the boring bar. In my case it was not because the jaws were too far out, but because the pipe deformed under the jaw pressure and walked out - hence my original caution to you. I do agree that you probably did not deform the steel pipe sufficiently to be an issue. But I bet that if you used an inside micrometer, you would still have seen the 4 “jaw lobes” on the ID (and then later on the OD, when you cleaned up the outside).


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## ShawnR (Mar 13, 2021)

RobinHood said:


> Looks like you are making good progress. Nice looking drive wheel. Good “rescue” of the stuck steel tire off the hub. Yes, pipe does expand a lot.
> 
> Please don’t take this the wrong way, as nothing happened this time, but be very careful and aware of how far the jaws are sticking out while machining.


@RobinHood ...I would be an idiot to take good safety advice the wrong way! That is why I hang out with you guys...I don't know way more than I know....

Thank you for the specifics.....interesting. I did not know about the 1/3 rule but I did know that it did not look good at all......but, yes, I did it anyways..... I only ran at the slowest speed the lathe would go 150? I think, and took very light cuts. Thank you.




Crosche said:


> @ShawnR you are correct about the surface speed; however I don't think drive wheel temperature will be an issue.
> Chad



I was not too worried about drive wheel temperature. Misinterpretation? But maybe just never thought of that . Thanks for the input on the drive wheel positioning. I am starting to look at chassis options.

I finished the drive wheel today. As you suggested, I crowned it a bit. about 1.5 degrees per side. I think it looks good but running a belt over it will be the deciding factor. I made a mandrel for it so if I have to rechuck it, I should be able to to increase the crown. I also ran the assembly on the bench. It seems really smooth but have not even done a static balance on it. I just want to see how it looked. Hard to tell but the motor is running. I should have put a line on it.


----------



## ShawnR (Mar 13, 2021)

@RobinHood Back a few posts, I made a comment about "If I do this again, I would do it differently". I think part of the reasoning in making that statement, at the time,  was how precarious this setup was, and time consuming flipping back and forth, trying to true it with rough surfaces, etc. With a fresh pipe piece, I would grab on the inside and clean up the outside and half to 3/4 of the inside, up to the jaws. Then turn it around, grab it on the now clean inside, true the piece, and then finish up the other half of the inside.... and touch the outside if I have to. Could even do the crown now. But that is based on what I learned through this operation. I pictured a heavy press job, not a drop it in evolution.....That method probably would have saved me a ton of time too, and been safer.

Or go to a friends house who has a bigger lathe....but that would be no fun. 

Thanks
Cheers,


----------



## RobinHood (Mar 13, 2021)

To be honest, I did not see the part where you go “if I’d do it again...” before I posted my concerns which the set-up. 

Your lathe has plenty of swing for the project at hand. The chuck was too small for that particular operation. It happens.

That wheel is running nice and true and quiet. Well done.


----------



## ShawnR (Mar 14, 2021)

I truly am doing what has been done. A nice build with some tips at the end about things to watch for.


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## ShawnR (Mar 14, 2021)

At the cost of severe embarrassment, I am going to post a picture to give an idea of where I am going, with hopes of input.  My choices now are learn CAD or keep making chips so I am choosing chips.... 

The more I get into this, and with the number of plans available on line, anyone wanting one, especially with this group of talented individuals is going to do what I am doing, using what is in stock and winging it, buy plans and order what is needed. But when I started this, I hoped to end up with a set of plans (or group of ideas) that drew on input from a few and that we can post as original (or semi original) 

So, I have been trying to do something slightly different but yet, you still need a drive wheel, platen and tension wheel. Hard to vary too much from that. The thing I have been hung up on is building the motor mount and platen around a round piece of stock (pipe or bar) instead of building a hinge assembly to allow the platen to go vertical or horizontal. I think horizontal has more appeal with those that work with wood (sanding end grain.....hate sanding end grain...) and vertical more for metal workers, especially knife makers as proven that these sanders are mostly promoted by knife makers.....Chad......  Looking at my stockpile. I have lots of 1.5 " pipe, and other sizes. But I also have a couple lengths of 1x2 tubing from a project that did not materialize. So today, I kind of settled on a directtion to go in, but not sure of the specifics. This is where you come in. Don't be afraid to say it is not good but at the same time, have an open mind. 

Remember, I have not even seen one of these things so experience is squat! 

So here goes the embarrasement .....unless you are one of those guys that goes right to the photo first! 

Some explanation...... 
The motor drive wheel is on the left side, looking at the platen. Picture is kind of goofy there. The video above mentions this due to the left hand threads on the motor.
Motor mount and platen rotate as one with the round pipe being the "axle". 
Bushings and collars will be used where necessary but the axle must be removable so not welded at both ends. I picture the motor mount assembly being welded in place.
The axle passes through the 1x2 tubing, bushed for stability.
The platen has 2 different sized wheels so if you need a narrower wheel, rotate (tilt) it back and for a wider wheel, rotate it the other way. Vertically, it has a flat surface. This establishes a 3 in 1 attachment instead of needing more attachments. Downside I can envision is having the tensioning mechanism flexible enough to accomodate a single wheel contact set up with the platen set up. Know what I mean? 
Will the 1.5" pipe be rigid enough for an axle? I am thinking a solid insert from the front to the first bulk head might be necessary.

I think that is all I got for you right now. I probably missed some points that are spinning around in my head but hoping this gets the conversation going. 

Let me know what you think.

Cheers,


----------



## YYCHM (Mar 14, 2021)

I don't get this thread.....






Why does it have to be so complicated?


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## Crosche (Mar 14, 2021)

ShawnR said:


> At the cost of severe embarrassment, I am going to post a picture to give an idea of where I am going, with hopes of input.  My choices now are learn CAD or keep making chips so I am choosing chips....
> 
> The more I get into this, and with the number of plans available on line, anyone wanting one, especially with this group of talented individuals is going to do what I am doing, using what is in stock and winging it, buy plans and order what is needed. But when I started this, I hoped to end up with a set of plans (or group of ideas) that drew on input from a few and that we can post as original (or semi original)
> 
> ...



Just my 2 cents, but I think that you are going to make your life really difficult if you choose to use the 1.5" pipe because it doesn't provide you a flat surface to reference off of. Alignment of your platen will become a hit and miss affair every time it is removed. Please bear in mind that the fit between the sleave and the tooling arm doesn't have to be a tight fit, you just need two flat surfaces which are parallel to register from. Round pipe will not provide you with surfaces to ensure repeatable alignment of the wheels on the platen to the drive wheel and tracking wheel. 
Getting the alignment of the 4 wheels can be tricky and poor alignment will either cause the belt to wander side to side or come off the machine completely.


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## ShawnR (Mar 14, 2021)

@YYCHM

lol...true....good point

I like making stuff I guess.....

With the number of plans, kits, and premade models available, some over $2000 US, I figure there must be something to the grinders. I won't know if it was worth it till I am done, but in the meantime, learning.


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## YYCHM (Mar 14, 2021)

I can see the belt width being a plus.  What magical about the 72" length?


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## ShawnR (Mar 14, 2021)

Crosche said:


> Just my 2 cents, but I think that you are going to make your life really difficult if you choose to use the 1.5" pipe because it doesn't provide you a flat surface to reference off of. Alignment of your platen will become a hit and miss affair every time it is removed. Please bear in mind that the fit between the sleave and the tooling arm doesn't have to be a tight fit, you just need two flat surfaces which are parallel to register from. Round pipe will not provide you with surfaces to ensure repeatable alignment of the wheels on the platen to the drive wheel and tracking wheel.
> Getting the alignment of the 4 wheels can be tricky and poor alignment will either cause the belt to wander side to side or come off the machine completely.



mmmmm...makes sense. Maybe that is why none of the plans I have seen so far does it. That is the kind of input I need. Thanks


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## Dabbler (Mar 14, 2021)

@YYCHM Longer belts allows more cooling of the abrasive media at high SFPM speeds.  72" is because of the popularity of some very expensive knifemaking grinders in the 80s.   3X79 was another popular size at the time, machines are still available, but mostly tailored to the woodworking industry.  3X79s are good for metalworking as well and allow superior cooling at SFPM speeds of 3000FPM+

I use 6X48 machines because it is what I learned on, and I like that format.


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## ShawnR (Mar 17, 2021)

I started a furnace many years ago and the thought of this sander got me going to finish it. The build is documented on the home foundry site. I finally got to melt aluminum on Monday. On the right road to making more wheels.  Another learning curve to climb...

The turned pieces actually feel better than they look, but it is not great. I made a few mistakes that I think doing more will help make a better cast


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## Tom O (Mar 17, 2021)

Nice what did you use for a mold? I have been toying with the idea of trying a steel tube and see if it will release due to the contraction of the aluminum.


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## ShawnR (Mar 17, 2021)

Tom O said:


> Nice what did you use for a mold? I have been toying with the idea of trying a steel tube and see if it will release due to the contraction of the aluminum.



I just used soup cans in varying sizes. They looked like they would have released except for the undulations in the side of the cans. I am wondering about that too. This was my first time melting anything so I am good with learning as I go. According to my sources, I probably heated the aluminum too long. I thought longer was better but turns out it is the other way. As soon as it melts, pour. 

Guess I got my tomato sauce recipe mixed up with my molten aluminum recipe...hate it when that happens! 

I had to cut the cans off to free the cast. 

Also, consider if the steel pipe should be hot before pouring in the melt. I wonder about temp shock and how it might affect the cast or at least the surface. 

I wondered too about pouring the aluminum into aluminum pipe.....now hear me about this before you laugh....I have large (2-5 inch) aluminum pipe. If the diameter is good but you want to make a solid wheel, what happens if you fill it with aluminum? I wondered if it would solidy before melting the pipe. If it worked though, you have the finished surface ready to go. If I try it, I will do it in a pan first though should it go south and I have a meltdown, it will be contained......


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## Tom O (Mar 17, 2021)

I would say it would pop through on the other hand if your going to machine it anyways why bother I’d keep the pipe for that future project that hasn’t surfaced in your head yet.


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## ShawnR (Mar 17, 2021)

Yea, true enough.


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## ShawnR (Mar 21, 2021)

Tom O said:


> Nice what did you use for a mold? I have been toying with the idea of trying a steel tube and see if it will release due to the contraction of the aluminum.



Tom, I used steel pipes today for molds as I needed that dimension. It seemed to work great! I just cut random sizes cause I just wanted stock dowel and tack welded it to a plate. When they were cool, I cut the welds and banged the aluminum casts out. They did not fall out but it did not take much to get them out.


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## Tom O (Mar 21, 2021)

That nice to hear from what I have read the shrink rate is 1/4” per foot for aluminum so it should be good for larger sizes and it is nice to see the idea proven.


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## ShawnR (Mar 25, 2021)

Back on track with this project the last few days. I decided that my best option is to combine ideas from those ones easily viewed on line rather than try to be too different.... And, I guess, I am not that original...I like the revolution model best but need to make the whole motor part different. I will probably do feet instead of the flat plate he uses, all minor changes.

The next step for me was to get the stock material. I needed one piece of 1 1/2" square tube. I, as previously discussed, then needed to remove the inner seam on the 2" tube. I started making one of the tools that guides the 3/4" burr ...had bearings out, steel plates, was going to weld, etc...it became a project in a project. I also looked at the seam and realized it was not centered so to make a guide for the one piece of tube with an off centre seam or make an elaborate tool that is adjustable....well,....no. I decided to use a piece of wood as a guide. I drilled a 1/2" rod to accept the burr shank and tapped a couple of set screws to hold it. I then turned down the other end to fit in a regular drill. I filed the first few inches down and then used the wooden guide. It worked great and did not take too long. The guide allowed me to work the burr back and forth laterally. I found that I had more control by using a push stick to push the guide to the end and then cut while I pulled the burr back. Not the most Gucci way to do it but got er done.

On to the frame/body next.


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## Dabbler (Mar 25, 2021)

I've been thinking a lot about this over the past few weeks. 

--There are two sets of plans all ready available and affordable.  Phil Vandelay's, which is less intricate, and more for a machinist, and Jeremy Schmidt's, which needs a lot of welding, but is more versatile.  They both tilt, but it is easy to edit that part out of the plans.

They both have youtube channels, and describe in detail their grinder and the build.

Phil: https://www.etsy.com/listing/823825...eprints?ref=landingpage_similar_listing_top-2

Jeremy: https://www.etsy.com/listing/969297...ing-belt-grinder?ref=shop_home_active_1&crt=1

[edit]  I should add that if I were to build a 2X72 belt sander, I'd use a 3/4 horse or 1 horse 3phase motor/VFD and do a very different design, more likely based on typical vertical sanders, like post #45.  The knifemaking ones look cool and are neat, but I don't think I'd need the versatility.  My 2c worth.

My 2 - 6X48  sander/grinders are  1HP and 3/4HP fixed speed models.


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## David_R8 (Mar 25, 2021)

Mark Winquist built a really simple belt sander that I've thought about building (like I need more projects!)
Would need to have a tilting table for my needs though.


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## Dabbler (Mar 25, 2021)

That's closer to what I'd build....  Thanks for the link -  I really like Mark's videos.


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## ShawnR (Mar 25, 2021)

Dabbler said:


> I've been thinking a lot about this over the past few weeks.



That is good. 



Dabbler said:


> --are two sets of plans all ready available and affordable.  Phil Vandelay's, which is less intricate, and more for a machinist, and Jeremy Schmidt's, which needs a lot of welding, but is more versatile.  They both tilt, but it is easy to edit that part out of the plans.



There are several plans available. The ones I have been leaning towards are the revolution model

https://www.etsy.com/ca/listing/767...-set-of?ref=landingpage_similar_listing_top-2

All have features that are appealing to to us, depending on what we want I guess. I feel Vandelay's model is complicated to build ie lots of parts and Schmidts model seems finicky with the welding of the bar stock to fit the tube and for me, I did not have convenient flat stock to work with. I, so far, ( ie not committed yet to much) have the sliding parts working so now just onto structure. Yes, the 48" models would be much easier and in hindsight, might have been a good way to go. A wannabe knife maker pointed me towards the 2x72 Schmidt version, and I fell into the rabbit hole (as I am prone to do) so here I am. There are lots of great plans out there. I, originally, when I started this thread, was hoping to develop a set of plans that we could post as our own but it looks like this will just become a build thread. At least we have all had some good input. For future visitors, hopefully, they can gain from it.

Thanks
Cheers


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## ShawnR (Mar 25, 2021)

Cleaned up the last of my aluminum castings today. Some are good, some look a little roughish but I think they will all work. Need to decide what size wheels I want.

@Crosche any suggestions? Does different size wheels at the top and bottom of the platen make sense for having the versatility to rotate the platen for different size radius? Or does that bring other issues? I am wondering about maintaining belt tension. Would have to plan that out carefully with dimensions. 

I was thinking of doing my platen like the one shown below. I like the idea of the wheels being supported on both sides though and have 1x2" material so it should be easy enough. I think it would be more rigid than a one sided axle for the wheels. Most platens that I have seen are made of 1/2" plate.


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## Crosche (Mar 25, 2021)

ShawnR said:


> Cleaned up the last of my aluminum castings today. Some are good, some look a little roughish but I think they will all work. Need to decide what size wheels I want.
> 
> @Crosche any suggestions? Does different size wheels at the top and bottom of the platen make sense for having the versatility to rotate the platen for different size radius? Or does that bring other issues? I am wondering about maintaining belt tension. Would have to plan that out carefully with dimensions.
> 
> I was thinking of doing my platen like the one shown below. I like the idea of the wheels being supported on both sides though and have 1x2" material so it should be easy enough. I think it would be more rigid than a one sided axle for the wheels. Most platens that I have seen are made of 1/2" plate.




The different wheel sizes are nice to have, but I would only do that if the wheels are rubber coated; bare aluminum isn't great to grind hard materials on so you probably won't use them much. Stick to the same diameter wheels if your wheels are bare aluminum, because it will simplify your build. Also, I would reconsider building an adjustable platen. Please see attached photos of my platens.
Nice castings BTW.


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## ShawnR (Mar 26, 2021)

Crosche said:


> The different wheel sizes are nice to have, but I would only do that if the wheels are rubber coated; bare aluminum isn't great to grind hard materials on so you probably won't use them much. Stick to the same diameter wheels if your wheels are bare a
> Nice castings BTW.



Thanks Chad. That is a heavy duty sander! I am going to look at options today and decide what direction to go in. And will go with the same size wheels. 

Cheers,


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## Tom O (Mar 26, 2021)

Couldn’t you make a slide/press on plastic or rubber that would slide onto the axle?
 You would have a good assortment from gas line to water line available.


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## ShawnR (Apr 1, 2021)

Tom O said:


> Couldn’t you make a slide/press on plastic or rubber that would slide onto the axle?
> You would have a good assortment from gas line to water line available.



Probably...depending on what one has access to. I have no idea what will be wanted yet with it but I like your idea....adds options.

@Crosche what size shafts do the platen bearings use? Would half inch be heavy enough? I might make the wheels next. I have the base plate and vertical components cut but then bogged down with other projects. I keep moving the chunks of aluminum around my bench so might as well make them into something useful. I can order the bearings for them too once I know what size shaft I should be using. I am considering a 2 sided support too so I guess in that instance, half inch would be lots but I am wondering what the one sided platens use for bearing supports. I don't know what kind of tension gets applied to the belt.


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## Crosche (Apr 1, 2021)

@ShawnR Yes, both of my platens have 1/2" shafts for the pulleys. Shoulder bolts work well for the pulley shafts.


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## ShawnR (Apr 6, 2021)

Started putting some stuff together today. I have been trying to come up with a drawing in FreeCAD before I put stuff together but losing too much time so I decided to just go at it. But then..... realized that it would be nice to be able to have an idea of where to put parts and how long to make them so back to FreeCAD... but only to layout things out 2 dimensionally. I don't have my head around planes exactly yet so positioning parts forward and aft has me a little puzzled. But I was able to get what I needed, and that is practical lengths for the components. The only actual metal stuck together right now is the two posts and the flat plate bottom. If anyone wants to have my FreeCAD drawing to load into their FreeCAD to practice with or play with, I can email it but can't upload it here so just a pdf for now.


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## YYCHM (Apr 6, 2021)

Post it in a zip file.


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## ShawnR (Apr 6, 2021)

YYCHM said:


> Post it in a zip file.



mmmm...learn something new everyday.....

Thanks!


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## ShawnR (Apr 8, 2021)

Little more progress....
Disregard the "Front" and "Motor" designations . Plate is symmetrical and I just needed to work on this side. I had some old pipe that fit the motor diameter so it formed my motor mount.


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## Mcgyver (Apr 9, 2021)

Dabbler said:


> @YYCHM   72" is because of the popularity of some very expensive knifemaking grinders in the 80s.   .



Dabbler, curious see what these look like - any particular brand names?

Shawn, I'm watching the build...thanks for posting it all.  Did you get the drawings from Jeremy Schmidt as a precendent or entirely your own design?

I've decided I want one of these but am waivering on what to build - the tug on war making the the perfect swiss army knive version that is does everything....or just getting on with something simple.  I do see the benefit of tilting, quick and easy belt changes....maybe a tilting table as well as something that is very solid and smooth running.  Is variable speed much of a desirable feature?  why - more control over the removal rate or some such thing?


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## ShawnR (Apr 9, 2021)

Mcgyver said:


> Dabbler, curious see what these look like - any particular brand names?
> 
> Shawn, I'm watching the build...did you get the drawings from Jeremy Schmidt as a precendent or entirely your own design?
> 
> I've decided I want one of these but am waivering on what to build - the tug on war making the the perfect swiss army knive version that is does everything....or just getting on with something simple.  I do see the benefit of tilting, quick and easy belt changes....maybe a tilting table as well as something that is very solid and smooth running.  Is variable speed much of a desirable feature?  why - more control over the removal rate or some such thing?



Slow build...getting distracted and trying to learn FreeCAD along the way. Spending too much time in front of the computer and not enough time making chips.....so be patient....

I do have Jeremy's plans that a friend purchased but not using them. I do refer to the Revolution model ( link below) but just from photos from the websites, no plans. So mine will be kind of based around that. 
I also received plans from a member here so am referring to them a bit too.
Yes, my personal requirements are tilting belt and tilting, independant table. I am working on the platen now, using a 1x2x10" tube instead of one sided half inch plate. Mostly because I have lots of 1x2 and not much of 1/2" plate. I also think the bearings would be better supported by being supported on both sides but honestly, most of the belt sanders out there use one side support with a half inch shoulder bolt. Sometimes I have to swim up stream...

I also want variable speed. I think it would be important and I have several treadmill motors with controllers so that aspect is pretty easy for me. Why not? 

But, I have no experience with them so really fumbling along. @Crosche , as you would of seen, has been giving me good input since he has and uses one. 

Thanks for hopping in. 
Cheers,

https://www.etsy.com/ca/listing/767...XE-zw_uMZDYrJiPqyICIs0KfEhPswIkhoCWLMQAvD_BwE


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## Dabbler (Apr 9, 2021)

Mcgyver said:


> Dabbler, curious see what these look like - any particular brand names?



I don't remember any brand names, probably out of business by now.  I know of one in Airdrie, but I haven't heard from the owner in 5 or so years.   Sorry I can't help with exact information, but arrangement of the pulleys is similar to all the designs out now.  they ranged from 2000$ to 3000$ back then...


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## Crosche (Apr 9, 2021)

Mcgyver said:


> Dabbler, curious see what these look like - any particular brand names?
> 
> Shawn, I'm watching the build...thanks for posting it all.  Did you get the drawings from Jeremy Schmidt as a precendent or entirely your own design?
> 
> I've decided I want one of these but am waivering on what to build - the tug on war making the the perfect swiss army knive version that is does everything....or just getting on with something simple.  I do see the benefit of tilting, quick and easy belt changes....maybe a tilting table as well as something that is very solid and smooth running.  Is variable speed much of a desirable feature?  why - more control over the removal rate or some such thing?




Have a look at Nexus Grinders from Lethbridge.


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## Mcgyver (Apr 9, 2021)

Dabbler said:


> I don't remember any brand names, probably out of business by now.  I know of one in Airdrie, but I haven't heard from the owner in 5 or so years.   Sorry I can't help with exact information, but arrangement of the pulleys is similar to all the designs out now.  they ranged from 2000$ to 3000$ back then...



I've seen ones where you can change the front of them, basically switch from a flat platen to largish diameter wheel.  I wonder if that's the style you thinking of?  I can see how the large wheel would be useful for someone making a knife, i.e. to get the hollow grind...not sure I'd ever use it.  Doesn't matter, was just thinking that having a look the rolls royce might spruce up the chev 

There's also a bunch of drawings and ideas on grab cad (free)


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## Crosche (Apr 9, 2021)

Mcgyver said:


> I've seen ones where you can change the front of them, basically switch from a flat platen to largish diameter wheel.  I wonder if that's the style you thinking of?  I can see how the large wheel would be useful for someone making a knife, i.e. to get the hollow grind...not sure I'd ever use it.  Doesn't matter, was just thinking that having a look the rolls royce might spruce up the chev
> 
> There's also a bunch of drawings and ideas on grab cad (free)




You could always build the chassis for the grinder and buy the accessories; that will probably save you the most money with the least amount of time invested in the build.


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## ShawnR (Apr 9, 2021)

Good progress today. Made the axle for the rotating motor assembly. Just a half " rod with threads at either end. Still fascinating to be able to cut threads on a lathe.  I have little goals in life.... 

Then fitting up of the pivots for the main motor mount. In the revolution plans, and many others, there is a receiver below the main bar (aka top bar, rotating motor assembly...) for attaching a rest/table of some sort. I did not commit to it yet but looks like I am going that way, after being able to rotate the main bar today, I was trying to figure out another way of doing it but that looks best. Another example of either "don't reinvent the wheel" or "most plans have it that way for a reason". But regardless, good progress today. Some work on the platen too. Bearings for wheels are due this weekend so should be able to make them up. I actually am torn between getting this project done and saving the wheel making for the new lathe so I had a good project for it. But will plunge on with this one.


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## ShawnR (Apr 10, 2021)

@Mcgyver  a couple that look interesting....not plans though, although the vashti looks like a kit. I did not spend much time on the website

https://vashtigrinders.com/products/rift-2x72-belt-grinder-package
https://reederproducts.com/


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## Mcgyver (Apr 10, 2021)

nice, but wow on price...4600 US$!   I'd love to make one, but just don't know when I'll get to it.  I started another project today, top to bottom reconditioning of a very beat up Schaublin 70.  Like I need another project, but I've a promised trade pending so had to...and its a train wreck that needs everything.   I'll keep  the want of a belt grinder in mind and see if serendipity or the universe can work its magic


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## ShawnR (Apr 10, 2021)

Yea, kind of insane, eh? Some say why need one at all, some say a few features would be nice like tilting belt or table and some say gotta have the Reeder. Each to our own. I think a simple one would have been great for me but I wanted the project and to see what I would do with it, hence the adventure to make a "better mousetrap". It has also been the catalyst to finish the furnace to pour the wheels and now looks like it is becoming a FreeCAD adventure too. And learning lots else along the way so all good. 

Gotta admit, had to google "Schaublin 70"...that looks like a rewarding project! Trumps the sander....

Cheers,


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## ShawnR (Apr 10, 2021)

@Crosche Chad, how important/beneficial is it that the platen tilts? I am thinking that if the table tilts (easier to do I think) is it necessary or worth it for the belt to tilt too?


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## ShawnR (Apr 11, 2021)

Crosche said:


> The different wheel sizes are nice to have, but I would only do that if the wheels are rubber coated; bare aluminum isn't great to grind hard materials on so you probably won't use them much. Stick to the same diameter wheels if your wheels are bare aluminum, because it will simplify your build. Also, I would reconsider building an adjustable platen. Please see attached photos of my platens.
> W.



I see you answered my question in post 64.


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## Crosche (Apr 12, 2021)

ShawnR said:


> I see you answered my question in post 64.



If you are not grinding on the platen wheels very much or using different size wheels on your platen, then you may only want to build in enough adjustability so that you can square the platen to a grinding rest or table.


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## David_R8 (Apr 12, 2021)

Ran across this today @ShawnR
Nice build here. Perhaps some ideas for you. Like you need more inputs 




Interesting options for containing the mess that 2x72 grinders create.


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## ShawnR (Apr 12, 2021)

David_R8 said:


> Ran across this today @ShawnR
> Nice build here. Perhaps some ideas for you. Like you need more inputs



lol....input is good! I started watching both those before but never finished. I just looked at the design and finished project, and, well, you know....

But as my sander evolves, nice to see that some of the things I am doing or adopting (cause I don't recall where I saw it) are incorporated into that design. I ordered those pressure tubes yesterday to use instead of a spring. Today I was bent on changing the position of my wheel. I cut off the motor mount previously mounted and started looking at it in line with the platen main tube and platen, offsetting the motor more. I could hardly wait to get to the shop and try it out......But then, after cutting the motor mount free (only a few tacks) I saw some disadvantages to that and put it back where it was. When I get a little more done, I will post some photos.  I am still fumbling around. 

Yes, having never used one, I was not aware of the dust/grind that it produces. Goes hand in hand with the rapid material removal that they are popular for I guess. No surprise there. The dust shield Vanderlay is really nice. Definitely something to consider. 

Vanderlay does some nice projects and videos. He does a power feed mod to his mill, which is the same mill I have, that has me ....planning..... 

Thanks! 

Cheers,


----------



## ShawnR (Apr 22, 2021)

Made a bit of progress and a bit of learning in the last week or so. I made a mandrel and turned the first wheel, thinking I needed the mandrel, but have since decided that, although I think it might be the best way to do it, it might not be necessary for this project.  Reducing the stock and turning it around seemed to work ok, for me. I put the wheels on the shafts and spun them by hand and they seem to have very little eccentricity (is that a word?) 
So all the wheels are done. I probably should have saved the job for the new lathe but wanted to get this step done to move on. Completing the platen is next. It is mostly done as well. Now that the wheels are done, I can position the wheel brackets and tack weld in to place. I can then figure out the mounting brackets for the platen to the chassis. The wheels have a little porosity. Certainly not beautiful aluminum but I am ok with it considering it was my first time melting and pouring/casting aluminum so it is kind of a novelty for me. I think I mentioned earlier in this thread, they feel better than they look. Should work fine.


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## ShawnR (Apr 24, 2021)

Wishing I had a rotary table yesterday....and still today,...

Any tricks to finishing this without a rotary table or DRO? I am thinking just keep grinding away...literally, once I have the bulk removed. 

Pivot plate


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## ShawnR (Apr 24, 2021)

After posting this, I am thinking that a tool grinder with an end mill mounted in the tool post on the lathe. Then the material in the 4 jaw or on a faceplate. Off to explore...


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## YYCHM (Apr 24, 2021)

ShawnR said:


> After posting this, I am thinking that a tool grinder with an end mill mounted in the tool post on the lathe. Then the material in the 4 jaw or on a faceplate. Off to explore...



What is it that you need to do to that piece?


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## RobinHood (Apr 24, 2021)

Drill and ream a ”fixtuing hole” at the center of the arc. Mount a corresponding pin vertically to your table. Slip the piece over the pin - now it will pivot around the pin. Move in either x or y the required radius amount. Clamp the part, drill a hole, undo clamp, move part a bit, clamp, drill, repeat until you are done your arc. Use an end mill to clean up the slot.


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## ShawnR (Apr 24, 2021)

YYCHM said:


> What is it that you need to do to that piece?



Cut an arc in it. The part is the bracket that secures the grinding belt when you rotate it from vertical to horizontal or any angle in between. I just need to cut an slot for the bolt.





RobinHood said:


> Drill and ream a ”fixtuing hole” at the center of the arc. Mount a corresponding pin vertically to your table. Slip the piece over the pin - now it will pivot around the pin. Move in either x or y the required radius amount. Clamp the part, drill a hole, undo clamp, move part a bit, clamp, drill, repeat until you are done your arc. Use an end mill to clean up the slot.



I had that kind of set up but was considering (briefly) trying to rotate the part by hand. Securing it between cuts would have been better than what I did, which was to adjust the xy each time.  Now I am at the file file file stage but almost done. Thanks. I will know for next time.

I think the lathe idea would have worked but all I had in a 1/4" shank was a carbide burr. If I had a 1/4" mill that fit in my die grinder, it might have worked with light cuts.


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## Doggggboy (Apr 24, 2021)

Lacking both a mill and a lathe, and for that matter any basic machining skill, I did mine the old fashioned way with the drill press and a carbide burr in the die grinder. Clean up with a file and you're gold.
On my build at least the curved slot is not a critical dimension as long as it clears the clinch bolt and allows for the rotation of the platen.
But yours is going to be better looking for sure


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## ShawnR (Apr 24, 2021)

Doggggboy said:


> Lacking both a mill and a lathe, and for that matter any basic machining skill, I did mine the old fashioned way with the drill press and a carbide burr in the die grinder. Clean up with a file and you're gold.
> On my build at least the curved slot is not a critical dimension as long as it clears the clinch bolt and allows for the rotation of the platen.
> But yours is going to be better looking for sure



lol...thanks but doubt mine is better looking. That is what heavy coats of tremclad is for!  However, it did work out ok. I mentioned the part today was for the main belt part but is actually for the platen. The contraption is starting to look like a belt sander. I realized that when I made the platen up, I did not think about the height above the bench so I will need to add feet to the bottom of the base. The lower wheel contacts the bench (just) so I need to elevate the whole thing an inch or so....


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## Doggggboy (Apr 25, 2021)

ShawnR said:


> lol...thanks but doubt mine is better looking. That is what heavy coats of tremclad is for!  However, it did work out ok. I mentioned the part today was for the main belt part but is actually for the platen. The contraption is starting to look like a belt sander. I realized that when I made the platen up, I did not think about the height above the bench so I will need to add feet to the bottom of the base. The lower wheel contacts the bench (just) so I need to elevate the whole thing an inch or so....


Yours looks great!
Will your drive wheel be doing double duty as a contact wheel? I'm not sure if that is even a thing but it looks doable.
You are freestyling  much more than I am. I bought the House Works plans for the Revolution grinder. So far so good.
The only change I made was to use a treadmill motor rather than 3 phase. I know he says a treadmill motor will suck in the grinding dust and die sooner but I have a free one and am starting there. I lucked out on the motor and found that it has a 5/8ths keyed shaft rather than the standard threaded shaft for treadmills. The wheel kit I bought from Nexus Grinders has a 5/8 drive wheel hub. Sweet.
I also found that a 36 grit ceramic belt will remove your fingertips just by taking it out of the box. Ouch! Made cutting up habaneros for supper not pleasant at all.
I still have to make the platen and the platen mounts and the work table but it is inching along with the help of my HS & G mill, (hacksaw and grinder)


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## ShawnR (Apr 25, 2021)

Doggggboy said:


> Yours looks great!
> Will your drive wheel be doing double duty as a contact wheel? I'm not sure if that is even a thing but it looks doable.
> You are freestyling  much more than I am. I bought the House Works plans for the Revolution grinder. So far so good.
> The only change I made was to use a treadmill motor rather than 3 phase. I know he says a treadmill motor will suck in the grinding dust and die sooner but I have a free one and am starting there. I lucked out on the motor and found that it has a 5/8ths keyed shaft rather than the standard threaded shaft for treadmills. The wheel kit I bought from Nexus Grinders has a 5/8 drive wheel hub. Sweet.
> ...



Ours look very similar from a glance. Yours looks heavier duty. I am wondering if mine will be solid enough. I am trying not to over build it but hopefully, I don't make it too light. We are both using treadmill motors too. Cool! No, I don't plan on using the drive wheel for a contact wheel. It is crowned and it seems wrong to me...don't know why. I am working on the tensioning mechanism today. Almost have it done, I think. My motor had to go on the other side due to its direction of rotation and left hand threads holding the wheel on. With yours being keyed, it does not matter I guess as you can switch the power leads. As for dust, I think some good filter material around the air intake will take care of that. If you have an extra set of leads coming out of the motor, I believe they are for an over temp sensor. That could be wired into to an indicator as a warning or even a relay and power relay. Nice looking shop. Looks huge! 


Cheers, 




.


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## Doggggboy (Apr 25, 2021)

ShawnR said:


> Ours look very similar from a glance. Yours looks heavier duty. I am wondering if mine will be solid enough. I am trying not to over build it but hopefully, I don't make it too light. We are both using treadmill motors too. Cool! No, I don't plan on using the drive wheel for a contact wheel. It is crowned and it seems wrong to me...don't know why. I am working on the tensioning mechanism today. Almost have it done, I think. My motor had to go on the other side due to its direction of rotation and left hand threads holding the wheel on. With yours being keyed, it does not matter I guess as you can switch the power leads. As for dust, I think some good filter material around the air intake will take care of that. If you have an extra set of leads coming out of the motor, I believe they are for an over temp sensor. That could be wired into to an indicator as a warning or even a relay and power relay. Nice looking shop. Looks huge!
> 
> 
> Cheers,
> ...


The plans for mine called for 1/4 inch wall 2x2 tubing and 1 1/2 inch tubing. I used 3/16 wall for the 1 1/2 as it's all I could find. Seems pretty solid. The base plate is 1/4 and the motor plate and D-plate are 3/8. The 4 pivot plates are 1/2 inch which is serious overkill.
The square tubing gets tapped in a few places so the 1/4 inch thickness holds a thread securely. Platen support plate is supposed to be 1/4 inch with a high carbon steel platen on top. I guess lots of guys are using heat resistant glass for the platen now to avoid wear. I won't be making knives, I don't think, so not sure what I'll use. One Tuber just used regular glass tile and it seemed to hold up for him even making knives but that was a 6 by 48 sander I think.
Yeah, the shop is a blessing and a curse. 30 by 60 with 12 foot walls. It was just bare metal until a few years ago when I treated myself by insulating and finishing the interior, having it wired and heated and putting in a four  post lift. It's a nice play to play but I seem to be genetically incapable of keeping it tidy or organized. 
My wife and I laugh about it. Her hobby is honeybees and unless you are going to eat 1500 lbs of honey yourself you have to sell it, so she does. She is an all in kinda girl so to sell honey she got CFIA certified and we built a 30 by 30 extraction facility. Because she produces certified safe honey she does well. Makes money even.
My shop is the kinda place that money goes in and is never heard from again.
What are you using for motor control?
I use the old control board with a cheap pulse generator from Amazon. Works like a charm.


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## ShawnR (Apr 26, 2021)

Doggggboy said:


> The plans for mine called for 1/4 inch wall 2x2 tubing and 1 1/2 inch tubing. I used 3/16 wall for the 1 1/2 as it's all I could find. Seems pretty solid. The base plate is 1/4 and the motor plate and D-plate are 3/8. The 4 pivot plates are 1/2 inch which is serious overkill.
> The square tubing gets tapped in a few places so the 1/4 inch thickness holds a thread securely. Platen support plate is supposed to be 1/4 inch with a high carbon steel platen on top. I guess lots of guys are using heat resistant glass for the platen now to avoid wear. I won't be making knives, I don't think, so not sure what I'll use. One Tuber just used regular glass tile and it seemed to hold up for him even making knives but that was a 6 by 48 sander I think.
> Yeah, the shop is a blessing and a curse. 30 by 60 with 12 foot walls. It was just bare metal until a few years ago when I treated myself by insulating and finishing the interior, having it wired and heated and putting in a four  post lift. It's a nice play to play but I seem to be genetically incapable of keeping it tidy or organized.
> My wife and I laugh about it. Her hobby is honeybees and unless you are going to eat 1500 lbs of honey yourself you have to sell it, so she does. She is an all in kinda girl so to sell honey she got CFIA certified and we built a 30 by 30 extraction facility. Because she produces certified safe honey she does well. Makes money even.
> ...



I used similar tubing only to get the 1.5 sliding nicely within the 2x.025. Other than that, I used whatever else was handy. That is why I did not want to purchase plans. I would deviate anyways so I scaled from pictures on websites to get starting dimensions. It seems to have worked out ok, except for the platen lower wheel being about a 1/4' lower than the base. I am adding feet to the bottom of my base to compensate. My platen surface will be the glass, eventually, probably,...  so I positioned the wheels to give me room to put something in there as a wear surface. Re motor control, I am using the MC60 boards I got from some treadmills. There are some different variations and only one that I have requires a separate PWM circuit. 2 others just require a control. I have the components to make up the circuit as it is pretty simple but I also purchased a small DC Motor control to use as the PWM source. Have not experimented with that yet. 

How long does it take for bees to make 1500 lbs of honey? Is that an annual production? What does an extraction facility look like? Are you in Canada? Your profile says Germany so wondering if you are from there and living here now, or the other way around, or just like hanging out with us Canadians....I could see that....

Cheers,


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## Doggggboy (Apr 26, 2021)

ShawnR said:


> I used similar tubing only to get the 1.5 sliding nicely within the 2x.025. Other than that, I used whatever else was handy. That is why I did not want to purchase plans. I would deviate anyways so I scaled from pictures on websites to get starting dimensions. It seems to have worked out ok, except for the platen lower wheel being about a 1/4' lower than the base. I am adding feet to the bottom of my base to compensate. My platen surface will be the glass, eventually, probably,...  so I positioned the wheels to give me room to put something in there as a wear surface. Re motor control, I am using the MC60 boards I got from some treadmills. There are some different variations and only one that I have requires a separate PWM circuit. 2 others just require a control. I have the components to make up the circuit as it is pretty simple but I also purchased a small DC Motor control to use as the PWM source. Have not experimented with that yet.
> 
> How long does it take for bees to make 1500 lbs of honey? Is that an annual production? What does an extraction facility look like? Are you in Canada? Your profile says Germany so wondering if you are from there and living here now, or the other way around, or just like hanging out with us Canadians....I could see that....
> 
> Cheers,


Germany? Lol.
Kronau, Saskatchewan. 
Facebook thinks my wife's apiary is in Germany sometimes as well. Drives her crazy.
The honey was just from one year's production from about 10 or 15 hives. Saskatchewan has some of the highest per hive production in the world because of our short but intense growing season where everything flowers at once. That and the oceans of canola.


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## Bofobo (Apr 26, 2021)

Just started using mine, and steel dust collection is now my enemy. All scrap No plan and thread to follow soon. Thanks for the write up


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## ShawnR (Apr 26, 2021)

Doggggboy said:


> Germany? Lol.
> Kronau, Saskatchewan.
> Facebook thinks my wife's apiary is in Germany sometimes as well. Drives her crazy.
> The honey was just from one year's production from about 10 or 15 hives. Saskatchewan has some of the highest per hive production in the world because of our short but intense growing season where everything flowers at once. That and the oceans of canola.



Well, that is embarrassing. The first google hit for Kronau is Germany and that is as far as I went. I have never heard of it so ....well...  Welcome to Canada.....lol

I toyed with venturing into honey bees. We live semi rural and hearing about the need for bees, I thought it would be an interesting venture but the idea dwindled the more I looked into it. I should pursue it. More for the bees than the honey, although we do use honey, a bit. That is the extent of my knowledge though....bees equal honey and pollination...pollination equals food....I like to eat.  Seems worth it. We have a bit of a bee keepers community here.


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## ShawnR (Apr 26, 2021)

Made more good progress today or since last reporting. I made of feet for the base to get the bottom of the platen off the bench. I also shortened the front of the base a bit. I saw one set of plans with the base made with angled legs and liked the look so went with a variation on it. I also have the tracking wheel sort of set up. It pivots but I don't think I have enough room for a compression spring under the arm so need to figure something else up. An external tension spring working against the bolt would work but I don't like it so maybe an internal compression spring (internal to the arm)...still pondering. 
Got the tensioning tube in place. I am pretty happy with that. The spacer for the tube against the main tube was a PITA! Broken tap #1, crappy tap #2, missed a hole - rewelded then the broken tap! Weld all holes up and go to imperial screws which look like crap.....but it works. Need to find 8-32 capscrews. Funny how the smallest simplest parts can take the longest time sometimes! 

Once I get the tracking wheel mechanics figured out, I can apply power and watch the belts fly! 
and then figure out how I am going to mount a table. Been a fun project so far. Lots like LOTS of head scratching but looks like it might work. 

Cheers,


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## ShawnR (Apr 26, 2021)

Bofobo said:


> Just started using mine, and steel dust collection is now my enemy. All scrap No plan and thread to follow soon. Thanks for the write up



Yea, There is an earlier post from @David_R8 about dust collecting. It is good. I have not considered that much yet. Good on you for going no plan and using up stuff you have. Sometimes the best projects. 

Cheers,


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## ShawnR (Apr 27, 2021)

It lives!  Powered up the belt sander today. After working on the tracking mechanism this morning and finally coming up something that I like, I had to make up some bushings for the wheel bearings.  The standard washers for 12 mm bolts contacted the outer race so I made up bushings. Then set up the power supply. The full console you see in the video is not needed. I just needed the variable speed control for testing purposes and have not broken down the console. I won't even use the control from the console as it is pretty open so the dust will destroy it in short order, I think. I will make the electronics box as dust proof as possible but, well, you know,...it will get in there.

Next, I need a stop for turning the belt horizontal, then make up a box for the circuit board and do the final controls. Not sure if I will do a tach now or leave it for now. Getting into spring, my list of to do things is growing. Great the sander is running but still lots to do. I am pretty happy with the way it has evolved.


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## Doggggboy (Apr 27, 2021)

ShawnR said:


> It lives!  Powered up the belt sander today. After working on the tracking mechanism this morning and finally coming up something that I like, I had to make up some bushings for the wheel bearings.  The standard washers for 12 mm bolts contacted the outer race so I made up bushings. Then set up the power supply. The full console you see in the video is not needed. I just needed the variable speed control for testing purposes and have not broken down the console. I won't even use the control from the console as it is pretty open so the dust will destroy it in short order, I think. I will make the electronics box as dust proof as possible but, well, you know,...it will get in there.
> 
> Next, I need a stop for turning the belt horizontal, then make up a box for the circuit board and do the final controls. Not sure if I will do a tach now or leave it for now. Getting into spring, my list of to do things is growing. Great the sander is running but still lots to do. I am pretty happy with the way it has evolved.


Sweet.
Tell the truth. When you turned it up to 11 did you have your hand on the exit door to bail?
I fired mine up yesterday to work on the tracking as well. Scared the crap out of me but no casualties.


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## ShawnR (Apr 27, 2021)

Doggggboy said:


> Sweet.
> Tell the truth. When you turned it up to 11 did you have your hand on the exit door to bail?
> I fired mine up yesterday to work on the tracking as well. Scared the crap out of me but no casualties.



Yea, ok..I might not have had one hand on the door, but I definitely did not take it off of the control and I don't even think I turned it up to max. I think with my calculations, the belt surface speed at max motor speed would be stupid fast so I only revved it up and down to see the transition. Not sure how far I went with that control. When I do the control circuit, I will set up limits according to a surface speed of about 6000 fpm. I think the knife makers like 5 to 6000 fpm

https://www.redlabelabrasives.com/blogs/news/optimal-speed-for-a-belt-grinder


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## 6.5 Fan (Apr 28, 2021)

Very nice. When do you start production.


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## ShawnR (Apr 28, 2021)

6.5 Fan said:


> Very nice. When do you start production.



Production of knives or production of sanders?..if you mean sanders, .at the rate I work, they would be very expensive or I would need to give up beer I think and food.....


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## 6.5 Fan (Apr 28, 2021)

No need to give up beer and food, you will just go to bed hangry.


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## Darren (Apr 28, 2021)

I'm thinking of building something like a 6x48 soon. I may have missed it Shawn, but are you planning to buy abrasives locally? Where? Or is there a good Canadian source? I know nothing about where to source belts from. I do know that i want something that can hog metal fast. I have a spare 5hp 3ph motor and this might be the project for it.


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## ShawnR (Apr 29, 2021)

dfloen said:


> I'm thinking of building something like a 6x48 soon. I may have missed it Shawn, but are you planning to buy abrasives locally? Where? Or is there a good Canadian source? I know nothing about where to source belts from. I do know that i want something that can hog metal fast. I have a spare 5hp 3ph motor and this might be the project for it.



I could not find any locally so ordered some on line, Amazon I think. I have more than I need. But having said that, apparently, Superior coatings on Fort William Road has them in stock, or the 2x72. For 6x48, GP carry them? They have a wall of belts, iirc


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## Doggggboy (Apr 29, 2021)

ShawnR said:


> I could not find any locally so ordered some on line, Amazon I think. I have more than I need. But having said that, apparently, Superior coatings on Fort William Road has them in stock, or the 2x72. For 6x48, GP carry them? They have a wall of belts, iirc


I ordered from Nexusgrinders.ca. They are in Alberta but mostly deal with 2x72 stuff.


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## PeterT (Apr 29, 2021)

Local supplier sellings belts. Don't know about brands or price comparison. But he did some heat treating for me & was a good experience.
https://www.knifemaker.ca/Heat-Treat-Service/


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## ShawnR (May 20, 2021)

It has been a while since I updated but I have been working on the sander between other projects and life. It is almost done. I did the wiring today. I want to put a tach on it yet and thought I could steal the power for the tach from the control board but I will need to look more closely at that later. It won't be as easy as I thought it would be.

Since posting last, I capped the vertical supports, installed the horizontal stop plate and did the control box stuff, wiring and mounting, etc. I have yet to do final welding, make the wheel supports on the platen a little more pretty, and make up some nice handles and knobs for the various locking screws and tracking screw. I need the platen surface too. Might just be a piece of steel for now. Might try melamine and see what happens to it.  Nothing locks the sander in either vertical or horizontal position so a lock screw/gadget of some sort. 

The table mount caused me some delays but in the end, I like it. A piece of 1 3/8 round  bar turned down to slip into the 1.25" square tube with the full diameter left as a mounting point for the table. I stressed over how to make the table tiltable but realized that since the whole belt tilts, I probably don't need the table to tilt too. It will tilt when lifted to the highest position, only practical if using the belt vertically.

You will see the ammeter. I was measuring the current draw so that I can choose the right fuse value. It looks like it can go as high as 12 amps under load. The DC Motor says 21 amps on it but since this is out of a residential treadmill, I doubted it, however since retrofitting the treadmill motor into another piece of equipment, anything goes.... I thought better to fuse accordingly.

As always, open to input.


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## David_R8 (May 20, 2021)

Well done Shawn!


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## Brian26 (May 20, 2021)

In addition to adding a DRO to my Grizzly milling machine, I am also going to build some Kant Twist clamps - posted elsewhere. In addition to those projects, I am planning on making a 2 x 72 inch grinder, based closely on Brian House's design, which is all over YouTube...  Working with a family member who also wants one, so we will build a pair of these. Planning on using a 2HP, 3 phase motor with Chinese VFD. I like House's design and think I can handle the issues around getting two square tubes to slide together, one inside the other.


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## ShawnR (May 20, 2021)

Brian26 said:


> In addition to adding a DRO to my Grizzly milling machine, I am also going to build some Kant Twist clamps - posted elsewhere. In addition to those projects, I am planning on making a 2 x 72 inch grinder, based closely on Brian House's design, which is all over YouTube...  Working with a family member who also wants one, so we will build a pair of these. Planning on using a 2HP, 3 phase motor with Chinese VFD. I like House's design and think I can handle the issues around getting two square tubes to slide together, one inside the other.


@Brian26  , I would say my build is based mostly on Brian House's, although ideas from other builds came into it. And input from members here. I did vary in order to use stock I had.  As for sliding tubes, see post #58. It worked well for me. There are also comments and links earlier in the thread. The 3/4" burr makes removing the internal seam very quick and painless. I used the block of wood just as a hand support, being able to move it around. Not as slick as a custom made block to slide into the tubing but pretty versatile. I threw it into my tool box and then dragged it out last week again for another task.


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## ShawnR (May 21, 2021)

Today, working on finishing stuff....knurled knobs for adjustments mostly. Welded nuts on wheel screws. Seems to make sense. . Put the melamine platen plate in. I will see how the melamine finish stands up. A glass platen is a possibility. I think from what I saw on ebay, they are common in a size that will fit.

The knurling was kind of a test of the new knurling tool that came with the new lathe. In the past, I had the "scissor" type of knurler and it worked great. Maybe I just got used to it. The one that I tried today is the normal 2 wheel tool press it into the stock type. Not sure if it has a name. . I will have to practice I think. Not sure how hard to press, do I need a center? feed speeds, etc....Not overly impressed with the knurls but they are ok. If they really bug me, I can make new knobs...but that is down the list right now...

I am really happy with the lever to remove/install the belt. I looked at several options and material sizes but ended up with the 3/8 rod you see (and my first new knurl tool trial run) It is easy enough to just pull the tracking wheel to release the tension but the lever feels more .....professional? (More gooder..)

When I started sanding, it became evident that shrouding/shielding will be necessary. Sparks everywhere!  @David_R8 those video links might come in handy!

But the sander sands!  Speed works well. Popped the little 13 amp breaker in the power bar it was plugged into so will need to skip the power bar when using it. Not a problem for my planned location for it.

There seems to be a bump or something going on. Not sure if you can tell in the video. It might be a sander seam, or an issue in the speed controller. Not a problem at higher speeds. I thought it might be a platen issue but after moving the stock around, I don't think so.

Here is the test run.


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## Doggggboy (May 21, 2021)

ShawnR said:


> Today, working on finishing stuff....knurled knobs for adjustments mostly. Welded nuts on wheel screws. Seems to make sense. . Put the melamine platen plate in. I will see how the melamine finish stands up. A glass platen is a possibility. I think from what I saw on ebay, they are common in a size that will fit.
> 
> The knurling was kind of a test of the new knurling tool that came with the new lathe. In the past, I had the "scissor" type of knurler and it worked great. Maybe I just got used to it. The one that I tried today is the normal 2 wheel tool press it into the stock type. Not sure if it has a name. . I will have to practice I think. Not sure how hard to press, do I need a center? feed speeds, etc....Not overly impressed with the knurls but they are ok. If they really bug me, I can make new knobs...but that is down the list right now...
> 
> ...


MIne has a little thump in it as well. Realized it gets better if you don't have the belt on backwards but it's still there. I think it's the seam.Knocked mine off the stand and bent the motor shaft a good 3/8th on inch. Managed to get it pressed straight enough for only about a thousandth runout. Whew, I thought i was going to be motor shopping. And yes, nobody talks about the mess. Holy!


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## ShawnR (May 22, 2021)

I should have added some photos for those into....photos....


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## RobinHood (May 22, 2021)

That’s coming together nicely!


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## Tom O (May 22, 2021)

From what I have seen watching videos that is the seam of the belt and can be eliminated by rubber coated wheels.


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## ShawnR (May 28, 2021)

Still plugging away.  Some tasks take way too long! Took days to build the box for the tach, (figured out a nice size in aluminum, found some rectangular tubing that would work, cut ends, practiced tig welding before I started on the box, ran out of argon Sunday, after I actually started on the box,.... decided that steel would work, repeat process above, Migged it together, layout and cut a nice hole for the display, found out no room for connections in the back, and so on.....   ) and then get the tach working. Lost a couple of magnets along the way....apparently centrifugal force beats magnetic force. I heard them fly but no idea what they are stuck to in the shop....  And then I found out that the sensor only works on one pole of the magnet. I was wondering why it worked only sometimes. Spent sometime trying to fix an alignment issue when it was really a North South issue. Discovered that after reading the instructions that come with the tach... But the speed sensor works well now. The magnets are magnetically stuck to the inside of the drive wheel and epoxied into place too. ("they" cause one is the trigger and the other, opposite pole out, is there for balance. Probably don't need it but thought it wouldn't hurt)

Today's shop was mostly spent on the shrouding. I watched Vanderley's video again (see post #86) for ideas but did not get as particular as he did. Youtube does not need any more really good hobbyists so I am shooting for mediocre.  I am pretty happy with the shroud actually. I was not sure where I was going with it this morning when I started but found the pebbled aluminum tucked away and sizing seemed good. I tapped 1/2" aluminum rods for rests to hold the 2 tops covers and the motor rest is just a piece of 1/4" rod, welded to the motor mount and bent so that the shield rests on it. The top 2 shrouds have to move for belt changes and they seem to accommodate that ok.

Can't say I am 100% happy with the motor control circuit but I was waiting to get the tach installed to have an idea of what is going on. I seem to be able to bog the sander down by pressing the material too hard, and then when it catches up, it over shoots and over revs. The trick might be simply not to bog it, let the belt do the work. Also, the motor can go way too fast I think so now I will be able to tell where I am at. The drive wheel is about 21 inches circumference so looking at the tach, multiply for 20 for a quick value of belt speed, or 21 if particular (or 20.625 if really really particular...but I ain't) I had aspirations of using an arduino to display actual belt speed but not now. Maybe later.


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## Tom O (May 29, 2021)

Not bad it would probably help with the slipping if you extended the arm out more allowing  you to have the tracking wheel in a lower position that would give you more purchase on the drive wheel.


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## ShawnR (May 29, 2021)

Tom O said:


> Not bad it would probably help with the slipping if you extended the arm out more allowing  you to have the tracking wheel in a lower position that would give you more purchase on the drive wheel.



I don't think the belt is slipping. The motor is actually slowing down due to the control circuit, I believe. I have other MC60 controllers to try as well as another type so might experiment a bit. I would think the treadmill motor is strong enough since it drives a much larger belt with  a person on it, although the roller it drives is about 3" from this 6"+ drive wheel where I am direct drive so losing that advantage.


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## ShawnR (Jun 10, 2021)

Paint day! Best thing I can do for my welds...

One coat of epoxy primer. Hopefully paint later today.


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## Tom O (Jun 10, 2021)

Ah the final touches! So how do you find it now that you have used it for a while? Has any hindsight kicked in for any improvement?
I have just machined the rollers for mine I have a used belt that will serve to decide wheel placement then I can design the frame.


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## ShawnR (Jun 10, 2021)

Tom O said:


> Ah the final touches! So how do you find it now that you have used it for a while? Has any hindsight kicked in for any improvement?
> I have just machined the rollers for mine I have a used belt that will serve to decide wheel placement then I can design the frame.



mmm....have to think about it (or rather, I should but apparently, I am going to start babbling...)

For what time I did use it, I really liked it! It will be a great addition to the shop.

I don't like that I can bog the motor but that is a motor controller issue or user error. Letting the sander do the work with speed and not pressure should be fine. A couple of the "evolutions" I really like. I feel like it has been a long project but when I looked back to my first post, it has been just over 3 months. That was from no solid plan to casting wheels to painting. A lot of other stuff happened in there too so not too bad I guess. If I had a plan to follow, and it was my only project, from the beginning, it would have been faster. My whole backhoe took me a year to build. Each day, out to the shop and work on the next page in the manual. On this project, lots of sketching, head scratching, posting and reading responses, etc.....the base is a good example. I started out with the flat plate, but made the platen too big for that to work. I then added the feet and really like the look of it, and it made it more stable.

Tension and tracking mechanism work great! Tilt function in platen works great. Even the horizontal option works well and that was a real head scratcher! I wanted things to look good but of course function well. So I feel like I just kind of fumbled along. With the talents here on this forum,  I often thought others would do things differently but for me, it was a successful and rewarding project. After using it, it quickly became obvious that a shield was needed. That worked out well. I might do a pan like Vanderley did but it will most likely sit on my welding bench so not sure it will be needed. As long as sparks are not flying back in my face, it should be ok. The shield, as shown, does that. And it is light and adjustable.

I still need to decide on a platen. The melamine looks like crap but with the hard smooth surface, it actually works well. But I will be changing it out for something...maybe I will splurge on the tempered glass ones available on ebay..... Maybe those with these sanders can chime in and tell me what they use.....?

Thanks for asking @Tom O . If you look back through my posts, you will see most of what I did. If you have any questions, ask away but I have seen your work so pretty sure you don't need my input!

Cheers,


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## combustable herbage (Jun 10, 2021)

Hey Shawn looking great on the paint job, you've built yourself a nice machine and you learned a lot, and with a lot of guys on here you can always see improvements in the things we build even though we may never change or fix it we know it can be done better and that knowledge is valuable to other members looking at a similar project.    This is a quote I recently heard and its very true 
"Every model is wrong, but some can be useful"


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## Brian26 (Jun 12, 2021)

Brian26 said:


> In addition to adding a DRO to my Grizzly milling machine, I am also going to build some Kant Twist clamps - posted elsewhere. In addition to those projects, I am planning on making a 2 x 72 inch grinder, based closely on Brian House's design, which is all over YouTube...  Working with a family member who also wants one, so we will build a pair of these. Planning on using a 2HP, 3 phase motor with Chinese VFD. I like House's design and think I can handle the issues around getting two square tubes to slide together, one inside the other.



Clamp project update - have the second prototype of the 10ga metal arms for a 4.5" clamp here at home. Cut by a local company using their laser cutter. Very nice. I left the holes undersized enough to allow for reaming, but now I wonder if I should have specified them exactly. One hole (to be reamed to 5/16") I specified as .300", and it measured .2995 - plus looked great as well. 

2 x 72 inch grinder update. I had all the parts cut from 3/8 steel plate by the same local company that is doing the clamp parts. Very nice work using the computer files I bought from Brian House. Struggling a bit with the seam welds - not enough air to run my new 1/2 x 18-inch belt air grinder.

Just ordered a Chinese DRO for the large Grizzly, so that one no longer for sale. Kind offers from several of you to assist with the install and I may get back to you on that. The smaller tabletop Grizzly round column mill is now for sale and I have had a few expressions of interest. I will be replacing the Kijiji ad with a better description.


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## ShawnR (Jun 14, 2021)

I think this mostly wraps up this project. I am still fiddling with the power supply for the tach, or rather, the housing and wiring of it.  There is not a lot of room in the control box for additional wiring. The tach needs a separate 12 volt (ish) power supply. As mentioned earlier, I do not want to draw from the control board..so that lead to another supply (wall wart) which meant two plugs (ugly and not efficient) but then the stand was not designed for a second electrical box...yada yada yada...spent way too much time on this minor aspect of the project and still not happy with it so going to walk away. Should have just remounted the circuit board into a larger box from the beginning.  Need to make a nicer knob/lever on the table lock. Right now, it is just a 1/4" wing nut. I guess I missed it when I was doing the other knurled knobs. Future use will show if I need to make any major modifications. 

But otherwise, on to other projects. 

Thanks for following along and the input along the way.

Cheers,


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## Chris Cramer (Jul 24, 2021)

What motor did you use for this project? After making several knives with a cheap craftex belt sander, I've become determined to build a 2x72 belt grinder. I got some single phase 1hp motors for free, but I've read that 2hp is recommended for 2x72. Would 1hp work for a smaller sized square belt grinder that still uses 2" belts?


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## Chris Cramer (Jul 24, 2021)

Looking at the Grizzly g1015. If this grinder works well for steel as a vertical 2 wheel design with a 1hp motor; then do you think a 1hp 3450 rpm motor would be good enough for a 2 wheel 2x72 design?


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## Janger (Jul 24, 2021)

I think you should go with 2HP. Anybody got one in Calgary for Chris?


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## Crosche (Jul 26, 2021)

I agree with John, 2HP would be best. I am running 1.5HP on mine and it's OK, but not great.


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## Chris Cramer (Jul 27, 2021)

I decided to go for a 2hp motor on kijiji. The price was still $200 but I already have all the metal I need for the frame, and most of the other components that are needed.


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## ShawnR (Aug 5, 2021)

Chris Cramer said:


> What motor did you use for this project? After making several knives with a cheap craftex belt sander, I've become determined to build a 2x72 belt grinder. I got some single phase 1hp motors for free, but I've read that 2hp is recommended for 2x72. Would 1hp work for a smaller sized square belt grinder that still uses 2" belts?



Sorry @Chris Cramer , I have been away a lot this summer chasing fish and doing the cottage thing. I see you have good input already. My motor is 2.5 hp from a treadmill. I think the motor size is good but I believe my issues are with the controller. If I bog it, the controller takes a while to catch up. I find if I am patient (need work in that area), and let the belt do the work, the machine works great. A straight up 2 hp with no speed controller will work great. If you want variable speed, then the controller and motor type will determine your satisfaction, imho. 

What kind of 2 hp did you get? AC?DC? RPM?  

Are you planning on variable speed?


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## Brian26 (Aug 7, 2021)

I have started to build a grinder like this. After watching a lot of videos on the Internet, I decided to go with the Houseworks design - the Revolution 4 I think Brian calls it. I bought an air belt grinder for taking out the welds inside the square tubing. My compressor is not up to a continuous grind, so I have to do this about 1cm at a time - then let the compressor catch up. I bought the electronic files from Brian and had a local metal fabricator cut out all the parts for me (except for the tubing) using 3/8" steel plate - as recommended. This company did a fine job and I am very happy. Not just a great job, but a lot cheaper than buying the parts and having them shipped from Florida.

I got the square tubing locally. Turns out that 1.5x1.5x.25" square tubing is nearly impossible to find locally. I did get a quote from MS, but their price for this was more expensive that for solid bar stock. So, I think I am going to go with solid square aluminum. I have a milling machine to take off the corners for a great fit - a 3/16" round-over bit does the job. Planning on a 2HP 3-phase motor with a VFD. I considered a motor from a treadmill, but got freaked out a bit by those who report a short life for those motors because they are not sealed, and dust from any sanding operation could play havoc with the bearings. I plan on buying the wheels from Nexus in Lethbridge.

Also, I am not happy with the tracking assembly that comes with the plans from Houseworks. So, I plan to use the milling machine to make one that fits properly and is wider. There is about 1/16" of play in the design from Houseworks and while it might work OK, it seemed very sloppy to me. Even when I wear my woodworking hat, I generally aim for about .01" closeness of fit, so this part of Brian's design seems very odd. Should be quite easy to get a fit of 1 or 2 thou using the milling setup.

I am not a welder and have no plans to learn. I am working with my grandson who is also building one of these and he is a capable welder and will do that part for the both of us.


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## Chris Cramer (Aug 7, 2021)

I got a marathon electric 2hp 3450 rpm single phase motor. I'm confident that this motor will be powerful enough for metalwork, but since it is only single phase I will need to use a pulley system for variable speed.


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## George (Aug 16, 2021)

ShawnR said:


> So, to get the discussion going, here is what I am starting with. ....the pulley (more like a flywheel) on the motor is about 5 3/4" in diameter and about 1" wide. The grooves you see are for a micro v belt. So, to me, the wheel is too narrow to be a direct drive pulley, and I would like a larger diameter to increase surface feet per minute. Most knife makers ( correlating to efficency) seems to be about 5000 sfpm. I would like to keep the RPM in a reasonable range, although not sure what that is yet for these motors. Having said that, I have not tested the motor to see what it actually like to run at. But  I had a 7 inch diameter in mind ..about 2700 RPM. I would start with anything from the existing diameter to a custom made 7 incher (when stock avails itself to me. )
> The thread holding the flywheel on is a 1/2" left hand so easy enough to make a whole new drive pulley. Casting one? Making one out of pipe and plate? Modifying the flywheel? I have seen plans for shop built stuff before using MDF as the pulley. On a machinist's forum, this would be frowned upon but practically speaking, to bond a piece or two of MDF to the existing fly wheel  to have a 2" wide drive pulley,with the cast iron flywheel as the base ...... might actually work....
> 
> Mounting the motor...I don't like the existing mounting brackey but would reuse the holes in the motor chassis.
> ...


A good thing about stripping treadmills is the rollers are seamless you get 4 decent bearings and excellent tubes for casting aluminum inside,  once the aluminum is cooled it just slides out, i also have 3 treadmill motors for planned projects. Always on the lookout for treadmills FREE ones are always being advertised on a local buy and sell site, also get some nice smaller gauge steel round square and oblong, and if the driver board is fried, just buy a PWM off AliExpress, cheap as chips.


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## Chris Cramer (Sep 3, 2021)

I tested what I have built so far, and it doesn't really look like it does any more than my craftex belt sander. The craftex has a 1/2 hp motor  that reaches 3500 rpm, but the marathon 2hp motor only reaches 3450 rpm. Does the rpm make more difference then the torque?


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## Dabbler (Sep 4, 2021)

A 3450 rpm motor never reaches a full 3450 rpm except under non-loaded ideal conditions  the speed of the ebelt depends on the size of pulley.  The HP rating of the motor will tell you how much force it can overcome when sanding.  For instance:

I run a 1HP on a 6X48 sander on an 8" drum at 1725 RPM  that works out to about 3500 spfm with enough torque for everything I do.  My other 6X48 uses a 3/4 HP 1725 on a 4" drum or about half the sfpm at about the same  (or a touch more) torque.  the both cut about the same (for the work I do)  I run 2" 4o grit belts on the 3/4 Hp sander and 6" 80 grit belts on the 1HP model.

I like working slow and careful, so these sanders suit me.

Your concern should be that you have enough torque to not stall the motor (or heat it up too much)  The speed is just how fast you can remove the metal under non-stall conditions.

I've been toying with building a 2X72, but I'd probably go for a 1HP 1725 motor, with about a 10" driving wheel.  that gives 4500 sfpm, which is a little fast, but will make for nice finish with fine belts.


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## Chris Cramer (Sep 4, 2021)

Right, a 2 hp motor is probably recommended so it can drive a 72" long belt and withstand the force of both the tensioner and the user. It may be that the force of the tensioner is too high. I used a 100N gas spring for the tensioner, what would be recommended?


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## Dabbler (Sep 4, 2021)

Lots of guys overpower 2X72 sanders.  They want enough torque to *almost* break the belt, in order to increase metal removal.  I want less removal, as I don't like burning the metal.  Fireball tool build a sander with (i think) a 5HP motor.


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## Chris Cramer (Sep 4, 2021)

Yeah, I read online that the recommended speed of the delt depends on numerous variables, like the grit and type of abrasive, and the intended purpose of the tool. I'm using zirconia belts, the grit is 85, and my main purpose for this grinder is stock removal. Ceramic belts require high speed to work well, and fine belts would heat up too much over higher speeds - but that is not my intended use. If the motor does reach 3450 rpm with a 50N(11lb) gas spring, then the belt would run at 3643 SFPM with a 4" drive wheel.


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## Chris Cramer (Nov 29, 2022)

I made an upgrade on my 2 x 72 belt grinder. I decided to add a 6" contact wheel to the system to use for grinding a blade bevel more accurately. Many commercial grinders have a set up that allows you to change the contact point between the use of a contact wheel and a metal plate. I also purchased a single phase VFD from ATO that I can use to add variable speed to the 2hp single phase ac motor as well as the direction that it spins.


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## Degen (Nov 30, 2022)

I built mine a few years ago to solve a need using a single speed motor.

Personal observation is that it does a lot more than regular grinder with quick material removal.

Its is among the the top tools used in the shop.


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## Doggggboy (Nov 30, 2022)

Chris Cramer said:


> View attachment 28400
> 
> I made an upgrade on my 2 x 72 belt grinder. I decided to add a 6" contact wheel to the system to use for grinding a blade bevel more accurately. Many commercial grinders have a set up that allows you to change the contact point between the use of a contact wheel and a metal plate. I also purchased a single phase VFD from ATO that I can use to add variable speed to the 2hp single phase ac motor as well as the direction that it spins.


I never realized you could control a single phase AC motor with a VFD. I assume that is a better option then the old dimmer switch trick.


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## Chris Cramer (Nov 30, 2022)

It isn't recommended to use a three phase vfd for a single phase motor. The single phase output VFD that you can get from ATO is available for different sized motors the 2hp VFD cost 218 USD but cheaper single phase to 3 phase VFDs should only be used with 3 phase motors. 
Dimmer switches don't adjust the frequency, they only change the voltage which also changes the power of the motor. A VFD will change the speed with the frequency but the voltage will remain the same  for power.


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## Susquatch (Nov 30, 2022)

Chris Cramer said:


> It isn't recommended to use a three phase vfd for a single phase motor.



I totally agree, but I'd use much stronger words than that! How bout - *3phase VFDs will not work with a single phase motor*....... Heck, you can't even wire it up!


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## Degen (Nov 30, 2022)

Chris Cramer said:


> It isn't recommended to use a three phase vfd for a single phase motor. The single phase output VFD that you can get from ATO is available for different sized motors the 2hp VFD cost 218 USD but cheaper single phase to 3 phase VFDs should only be used with 3 phase motors.
> Dimmer switches don't adjust the frequency, they only change the voltage which also changes the power of the motor. A VFD will change the speed with the frequency but the voltage will remain the same  for power.


The better VFD's change both frequency and voltage as it prevents over  current, fail to do that and you greatly reduce motor life.  i was involved in selling the first VFD elevator drives in Canada.


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## Chris Cramer (Nov 30, 2022)

there is a way to wire it up, if you have it drawing power from all 3 phases, that is how the single phase VFD works, neutral is connected to one terminal, and the other 3 wires are all connected to the life terminal.


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## Susquatch (Nov 30, 2022)

Chris Cramer said:


> there is a way to wire it up, if you have it drawing power from all 3 phases, that is how the single phase VFD works, neutral is connected to one terminal, and the other 3 wires are all connected to the life terminal.



Really...... My brain just fried!

I would have thought that wiring all phases to one would create a massive short circuit and even if not they would all add to zero. But I confess I've never tried it. (And prolly never will.... ..... At least not from within the same room! LOL!) 

But I'm always open to learning new things!


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## phaxtris (Nov 30, 2022)

I can't imagine what @Chris Cramer is suggesting is ideal with a normal 3ph vfd, the phases being 120 apart and not 180 apart like in normal residential 240v power

I would also wonder if that third phase being returned to ground would cause some kind of load imbalance withen the circuitry of the vfd ?

Just some thoughts


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## Dabbler (Nov 30, 2022)

I can see that the wave forms will not be ideal for a 1ph motor, but in a garage-tinkering-way  it might work. -- Certainly not intended to be used that way.  I'm prety sure a 1ph motor will also have problems with the balancing on the run capacitor winding because of the timing differences.  It *should* cause extra heating in the primary winding, but most mills utilize only a fraction of the torque, so not so bad.

Hmmm might be worth a try one day...


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## Chris Cramer (Nov 30, 2022)

Sorry, you don't use all three phases, you use only one phases. Commercial buildings that use 3 phase power still have single phase power outlets by dividing the 3 phases into different areas, and the lights only use single phase. They just need to balance it to make sure a cable does not make connection with the same phase.


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## Susquatch (Nov 30, 2022)

phaxtris said:


> I can't imagine what @Chris Cramer is suggesting is ideal with a normal 3ph vfd, the phases being 120 apart and not 180 apart like in normal residential 240v power
> 
> I would also wonder if that third phase being returned to ground would cause some kind of load imbalance withen the circuitry of the vfd ?
> 
> Just some thoughts



I wonder too. Here is a phase graph. 





Note that every 60 degrees, two phases are opposite the other but half the voltage. A quick look says the voltage sum is always zero (what I guessed before). However, I think it results in some really nasty short circuits too. Again, kinda what I guessed before. 

However, vfd control systems do read their own outputs and Lord knows how they might adjust their outputs with such a connection. I stopped being so sure of myself on such things 30 years ago.


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## Susquatch (Nov 30, 2022)

Chris Cramer said:


> Sorry, you don't use all three phases, you use only one phase. Commercial buildings that use 3 phase power still have single phase power outlets by dividing the 3 phases into different areas, and the lights only use single phase. They just need to balance it to make sure a cable does not make connection with the same phase.



Ah, I see. I thought you said all three wires were connected to one pole. 

That makes more sense, but I can't imagine that the vfd would be very happy about it!


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## Chris Cramer (Nov 30, 2022)

You can't do that with the input of the vfd. For single phase to 3 phase VFDs the output could be divided.


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## Susquatch (Nov 30, 2022)

Dabbler said:


> Hmmm might be worth a try one day...



I wanna watch.......... from across the street! 

Jk! You could rig it up with a volt or two.......


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## Susquatch (Nov 30, 2022)

Chris Cramer said:


> You can't do that with the input of the vfd. For single phase to 3 phase VFDs the output could be divided.



I think I am not understanding you. Why do you mention the input? And what does divided output mean?


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## Chris Cramer (Nov 30, 2022)

When you said the VFD wouldn't ne very happy about it, I'm saying that the VFD input would still be wired correctly to single phase power. Then the 3 phase output could be divided to power a single phase motor.


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## Doggggboy (Nov 30, 2022)

Apparently there are single phase output VFDs.




__





						Wait? There are Single-Phase VFDs? | Wolf Automation
					

Yes, indeed! With the correct fittings there are single-phase motors that can include single-phase VFDs. Our tech support goes into details here!




					www.wolfautomation.com


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## phaxtris (Nov 30, 2022)

Chris Cramer said:


> When you said the VFD wouldn't ne very happy about it, I'm saying that the VFD input would still be wired correctly to single phase power. Then the 3 phase output could be divided to power a single phase motor.



i believe the question is that because the 3 phase is artificially generated in a single to 3 phase vfd that the output stage may not be happy only using 2 of the 3 output phases

single to single vfd i would imagine has some different electronics internally


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## Chris Cramer (Nov 30, 2022)

Yeah, that is why it isn't recommended to use it that way like I said the first time. The single to single phase VFD is different than the single to 3 phase VFD.


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## Susquatch (Dec 1, 2022)

Chris Cramer said:


> Yeah, that is why it isn't recommended to use it that way like I said the first time. The single to single phase VFD is different than the single to 3 phase VFD.



Sorry for confusing your information.  I got it now.

It still seems like a bad thing to do, but I get the idea now. As @Dabbler says, I'd be interested in doing some simple tests. Not doing that with the VFD's I have though. Someday I'll get a cheapo VFD and try it. @Dabbler can hit the go switch. 

Yes, a single phase to single phase VFD is the way to go. But I'd still rather use a 3phase motor.


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## Dabbler (Dec 1, 2022)

Ah!  not using a single phase VFD to a 3 phase VFD but only on one leg....  Rather using a 1ph to 11ph VFD designed for the purpose....  Now I get also!!!


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## Degen (Dec 1, 2022)

All I can add to this my motor shop (that I've know for over 30 years), when I suggested the topic answer was DON'T! With a strange look.  Short answers like that mean something.


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## Art M (Dec 1, 2022)

I'm a little late to the party here, as usual.
If anyone is interested in a bolt together grinder with side tilt check out Saber opensource grinder project.
Guy (Canadian I believe) named Dan Comeau who is a knife maker posted plans. looks really nice.
Was very good of him to put the time into it to post online.
I'm thinking of building that one or a KMG clone as we have one at work to copy.
The KMG is simpler to build just some flat bar and a bunch of holes to drill, the one we have at work I use for just general shop stuff I actually quite like it. I think a belt grinder of any kind is an extremely useful tool for any home shop.
Art


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## Dabbler (Dec 1, 2022)

@Art M are there any images or videos of a working Saber 2X72 grinder?

[update]  I found one myself:


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## Art M (Dec 1, 2022)

__





						OSG the Open Source Grinder project
					





					www.sayberosg.com
				



Link to cut files if you have access or a buddy with a water jet or laser table. I tried with a plasma table at work but the kerf from the plasma torch eats up too much. If someone way smarter than me knew how to modify the cut file you could cut it and drill the holes. 
Art


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## Art M (Dec 1, 2022)

__





						SAYBER OPEN SOURCE BELT GRINDER PROJECT - CAD Files, Build Instructions, Schematics BOMs and more for a world class 2" x 72" belt grinder
					






					dcknives.com
				



I think this is the home page
Art


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