2x72 sander

[ShawnR]

@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]

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]

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

 

[ShawnR]

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]

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

Why does it have to be so complicated?

 

[Crosche]

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,

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.

 

[ShawnR]

@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.

 

[YYCHM]

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

 

[ShawnR]

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

 

[Dabbler]

@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.

 

[ShawnR]

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

 

[Tom O]

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.

 

[ShawnR]

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......

 

[Tom O]

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.

 

[ShawnR]

Yea, true enough.

 

[ShawnR]

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.

 

[Tom O]

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.

 

[ShawnR]

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.

 

[Dabbler]

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.

 

[DavidR8]

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.