Sticky What Machines Do You have?

[CalgaryVB]

What machines do you have, what do you like and dislike about them, any upgrades you're looking at?

Personally, I have a Craftex Mini Mill (CT133)
-- I like that I have access to a mill in general. Dislike that I have to work within the little guy's limits. Hope to upgrade to a bridgport or similar manual mill in the next couple of years.

I also have a Craftex 10X18 lathe (B2227L)
- This machine is actually perfect for what I've been working on. Need to get it a quick change tool post, as it has the lantern style, which is a pain. Wish it had a quick change gear box, as changing out the gears is a bit tedious!

What about you guys?

Well. I'm new to this site

What machines do you have, what do you like and dislike about them, any upgrades you're looking at?

Personally, I have a Craftex Mini Mill (CT133)
-- I like that I have access to a mill in general. Dislike that I have to work within the little guy's limits. Hope to upgrade to a bridgport or similar manual mill in the next couple of years.

I also have a Craftex 10X18 lathe (B2227L)
- This machine is actually perfect for what I've been working on. Need to get it a quick change tool post, as it has the lantern style, which is a pain. Wish it had a quick change gear box, as changing out the gears is a bit tedious!

What about you guys?

I'm new to this site and to the hobby as well. Always been an handyman so now I'm interested in Metal Lathes. I'm looking for a mini metal lathe. Any suggestions on what and where to buy would be appreciated. Also, if this is not the place to post this thread, I apologize

 

[jcdammeyer]

Hi all,
New to the group.
I have the equivalent of a Grizzly G3616 mill, I made my own Gingery Metal Lathe using my gas foundry, sheet metal roller and power hack saw. Since then I've upgraded to a 1942 SB Heavy 10L and sold the roller and hacksaw. I have a 7" metal band saw. A 3:1 Brake/Shear/Roller and Corner notcher from Busy Bee. Air tools, small mig welder and oxy setup. Plus the usual set of tablesaw, bandsaw, drill press, jointer and planer. The gingery metal lathe is full outfitted with stepper motors on Z and X with a Electronic Lead Screw (no gears). The SB lathe has only a stepper motor on the carriage Z axis and a VFD and 3 phase drive on the spindle. Again I use an ELS to do all the power feed and threading.
I've also got a JGRO based CNC router run with MACH3 and a really cheap (but it works) 3D printer.
Working on adding CNC to the mill right now as the major project.

 

[PeterT]

Welcome to the group, jcdammeyer.
Sounds like you have some nice machines & know-how too. After ?some number? of posts I think the site allows picture uploading. Feel free to post some pics.
I'm very intrigued by the ELS.

 

[jcdammeyer]

Thank you. This group looks really interesting and active.
I've upgraded my profile to link my web site which is very out of date but has some project pictures. I posted a link to a youtube video in the posting about my mill. I then later read that links aren't allowed for 3 postings.

 

[Janger]

Welcome
Gingery lathe with ELS let’s see! Does it do threading? very cool project

 

[jcdammeyer]

Welcome
Gingery lathe with ELS let’s see! Does it do threading? very cool project

This is very old (2008) using one of the first prototypes. Now that I have a nice NIKON with 1080P capabilities I really need to make some new videos. Never enough hours in a day and I have no idea what the best video editing software is nowadays.

I've also used it as a rotary indexer. Set up the distance per jog step and each press of the button moves it so many degrees.

And here's an example of turning a taper.

 

[Dabbler]

Really cool! Nice work!

 

[jcdammeyer]

Really cool! Nice work!

Thank you. The rotary table episode was for drilling matching holes in stepper motor holders and covers and caps. All interchangeable for this project (JGRO CNC Router) which can be an entirely different thread.

 

[PeterT]

Very cool. Now with the ELS, is it tied to or somehow sensing the main headstock motor as part of its parameter setup, or can it be run independently
(ie. retrofil on lathe with plain vanilla stock single phase non-VFD motor).

 

[jcdammeyer]

Very cool. Now with the ELS, is it tied to or somehow sensing the main headstock motor as part of its parameter setup, or can it be run independently
(ie. retrofil on lathe with plain vanilla stock single phase non-VFD motor).

Like MACH3 CNC it uses a single pulse per rev sensor. I've used both optical and hall effect sensors for that. The pulse needs to be about 5 degrees of rotation wide. There is a minimum speed of about 30 RPM and a maximum of I think 8,000 RPM.

One idea I investigated but haven't taken further is porting the ELS code onto a BeagleBone Black so it can use a quadrature encoder. Or run MachineKit for full CNC. So you can use it mostly as a manual lathe, which is how the user interface is set up, or switch over and use it as a CNC lathe which requires a totally different frame of thinking.

But I've also got PIC32 processors which also do quadrature. So not decided yet. In either case I'll make something that plugs in place of the 40 pin DIP processor that is currently in a socket on the ELS. I went from a surface mount package to one that was in a socket so that this sort of upgrade could be done a decade or more later rather than trashing an investment.
John

 

[jcdammeyer]

Very cool. Now with the ELS, is it tied to or somehow sensing the main headstock motor as part of its parameter setup, or can it be run independently
(ie. retrofil on lathe with plain vanilla stock single phase non-VFD motor).

I think I may have misunderstood your question. The normal motion on the ELS is tied to the spindle speed. So if you want 0.003" per rev then the Z axis will move at a rate based on how fast the spindle is turning to move 0.003" for every turn of the spindle.

But there's also a flag you can set called BROACH mode. The spindle doesn't turn but you can still do multiple passes moving the X in or out on each pass duplicating the motion to cut a key way. That's how it could also be used on a rotary table.

 

[PeterT]

I guess I don't know what I don't know LOL

I understand that the carriage has to advance X linear mount per spindle rotation as an underlying principle of threading. So on my manual lathe, the correct gear combinations are selected, that turns the threading lead screw at some specific reduced ratio of spindle. The threading clam shells are engaged on the lead screw & the carriage advances according to the desired screw pitch.

So in my simple mind, an ELS would have to 'know' when the spindle has completed a revolution & then drive a lead screw some specific fraction of that related to the desired thread pitch. So I guess I'm asking, what is the minimum hardware required to retrofit a manual lathe with this capability? For example:
- some kind of sensor that knows the spindle clock position or I guess RPM if that makes more sense
- a new lead screw of some appropriate pitch or maybe ball screw & matching nut? Does this then replace the original lead screw which must be removed?
- a stepper motor that drives the lead screw. I assume it sits on the tail stock end
- the magic program box that accepts the threading inputs & coordinates turning the lead screw?

I kept this ELS link which has neat features
https://www.rocketronics.de/els/
But I haven't really come across a conversion/retrofit pictorial build post that shows the parts, what stays & what goes. Features like taper cutting would be super cool, but now I guess you need a stepper motor & ball screws on the cross carriage axis. So is this essentially a CNC lathe now other than no VFD control/feedback from the spindle motor. Or is that a prerequisite too?

Does your system have stop capability while its feeding? Like you can thread to a shoulder & the ELS knows to disengage?

 

[jcdammeyer]

I guess I don't know what I don't know LOL

I understand that the carriage has to advance X linear mount per spindle rotation as an underlying principle of threading. So on my manual lathe, the correct gear combinations are selected, that turns the threading lead screw at some specific reduced ratio of spindle. The threading clam shells are engaged on the lead screw & the carriage advances according to the desired screw pitch.

So in my simple mind, an ELS would have to 'know' when the spindle has completed a revolution & then drive a lead screw some specific fraction of that related to the desired thread pitch. So I guess I'm asking, what is the minimum hardware required to retrofit a manual lathe with this capability? For example:
- some kind of sensor that knows the spindle clock position or I guess RPM if that makes more sense
- a new lead screw of some appropriate pitch or maybe ball screw & matching nut? Does this then replace the original lead screw which must be removed?
- a stepper motor that drives the lead screw. I assume it sits on the tail stock end
- the magic program box that accepts the threading inputs & coordinates turning the lead screw?

I kept this ELS link which has neat features
https://www.rocketronics.de/els/
But I haven't really come across a conversion/retrofit pictorial build post that shows the parts, what stays & what goes. Features like taper cutting would be super cool, but now I guess you need a stepper motor & ball screws on the cross carriage axis. So is this essentially a CNC lathe now other than no VFD control/feedback from the spindle motor. Or is that a prerequisite too?

Does your system have stop capability while its feeding? Like you can thread to a shoulder & the ELS knows to disengage?

When I built my Gingery Lathe I used a couple of sewing machine belts to drive the Z axis (carriage) lead screw. The half nut would be engaged when I wanted motion. But for thread cutting I would need all sorts of gears and the associated hardware to mount and engage them. I'd have to build the shaper or mill to cut the gears. So instead I took the easy way out (for me) and started initially with the idea of electronic gearing.

That's just where an encoder on the spindle generates pulses that turn the stepper motor on the lead screw. With extra hardware counters/mutliplier/divider chips it would be possible to set ratios. But you still have to watch the threading indicator and where the tool is and release the halfnut on time. Or stop the spindle and run it in reverse (not possible on the Gingery) to return back to the beginning.

Instead I looked at MACH2 CNC and they used one pulse per revolution for threading. And, as it turns out for threading that's more than adequate if your spindle speed is consitant. Which it is if it's an AC motor synchronized to the AC line.

Now the rest of it is math. With a steady 600 RPM for example and a thread that matches the pitch of the lead screw (10 TPI) then the leadscrew also has to turn 600 RPM. If the pitch you want to cut is 20 TPI then the leadscrew has to turn half that speed. That's what the gears do. So as long as you start the leadscrew from a known point, accelerate up to speed over the same distance, the spindle will have turned N degrees. At that point the spindle and the lead screw are now synchronized.

The tool enters the previous pass and continues to cut until a set distance. It decelerates to a stop in the same runout area required for a manually operated half nut. If you don't have control over the cross slide X axis then at that point my display tells you to remove the tool. So you wind back the cross slide and press START. The carriage now returns to the starting position. And tells you to insert the tool.

How far? Well that depends. If you don't have a compound slide set at 29.5 degrees or so then the ELS is configured to tell you how far in to set the cross slide and it didn't return to quite the same place. In effect the tool follows the 29.5 degree angle deeper for each pass depending on the depth per pass setting.

Now if you have a compond slide you wind the cross slide out at the end of the pass. Tap START. The carriage returns and you then set the cross slide back to 0. I have an actual cross slide clamp that I can bump up against if I want to install it. Then the ELS tells you how far to move the compound slide, base again on depth per pass. And you can program a number of spring passes.

After each spindle index pulse the speed is recalculated and the carriage speed is tweaked but only enough for minor variations.

John

 

[jcdammeyer]

And just to elaborate a bit more in case you still have a few questions. Forget about the RPM now. Think of how many 20kHz TICKs can occur between a spindle index sensor pulses. That's a TICK every 50 milliseconds.

Say it's 2000 TICKs at the current spindle RPM. And say your leadscrew is driven with a Gecko Microstepping drive that does 10 steps per step resulting in 2000 steps per revolution.

So if you are cutting a lead screw pitch then you have to produces 2000 steps for the 2000 ticks that happen every revolution. Or, more precisely, at each TICK, create one step pulse. If you wanted to cut that 20 TPI thread then you'd create a step pulse every second TICK resulting in half the spindle speed and 20 TPI.

Internally the math takes care of a spindle speed of 1725.3333 ticks per rev to generate N step pulses per rev which work out to 1725.3333 steps per rev. So the math takes care of missing the occasional TICK and not generator a step pulse so the average number of step pulses over a revolution work out to 1725.3333 step pulses spread over the entire single revolution.

The devil is in the details but then I also released the source code so it's been available for the last 13 years or so. I published an article on electronic gearing for the lathe in Circuit Cellar Magazine November 2006.

 

[DavidR8]

Hi all, I’m a new machinist with just a 7x14 mini lathe to my name at the moment.
I also have a Miller MIG welder.
I have a full complement of woodworking machines, 1965 Unisaw, jointer, and a planer.
I’m trying to rid my garage of a load of junk from the previous owner (long story) so I can have some space to work.


Sent from my iPhone using Tapatalk

 

[jcdammeyer]

And just to elaborate a bit more in case you still have a few questions. Forget about the RPM now. Think of how many 20kHz TICKs can occur between a spindle index sensor pulses. That's a TICK every 50 milliseconds.

Note that should have been "That's a TICK every 50 microseconds. So 2000 TICKs per rev is 0.1 second which is 10 RPS which is 600 RPM.

 

[DPittman]

Hi all, I’m a new machinist with just a 7x14 mini lathe to my name at the moment.
I also have a Miller MIG welder.
I have a full complement of woodworking machines, 1965 Unisaw, jointer, and a planer.
I’m trying to rid my garage of a load of junk from the previous owner (long story) so I can have some space to work.


Sent from my iPhone using Tapatalk

Welcome to the forum. Do you have any first projects in mind?

 

[DavidR8]

Thanks.
I need to get my lathe cleaned up and in shape the I need to make some adapters so I can run a 1lb spool on my Millermatic.
It’s jury rigged now and I’m not fussy about it.


Sent from my iPhone using Tapatalk

 

[jcdammeyer]

Thanks.
I need to get my lathe cleaned up and in shape the I need to make some adapters so I can run a 1lb spool on my Millermatic.
It’s jury rigged now and I’m not fussy about it.

That's a great project!

 

[sanderzTM]

Hi all, I’m a new machinist with just a 7x14 mini lathe to my name at the moment.
I also have a Miller MIG welder.
I have a full complement of woodworking machines, 1965 Unisaw, jointer, and a planer.
I’m trying to rid my garage of a load of junk from the previous owner (long story) so I can have some space to work.

Forestry tools and heavy machinery equipment are one of the most important in our areas of Quebec. But there are a lot of difficulties with financing all the projects, which have heavy machinery and facility needs in it. When we've been starting our own business, we had to visit all the main creditors in Quebec and all the nearby provinces take some credits in exchange of our facility's guarantees.