Software & Electronics for Mini-Lathe?

[GlennW]

You'll need CAM software to convert the CAD file to G code, and then DNC software to send it to the machine, but that depends on the software you are using to actually run the machine.

[FLSTEAM]

You'll need CAM software to convert the CAD file to G code

Any suggestions on Lathe CAM software. I use MeshCam after Alibre STL files for my mill.

John B.

[GlennW]

I have not done any work with a CNC lathe, so I can't comment on suitable CAM software.

[ken572]

Steve,

These might be helpful.
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http://www.dakeng.com/lathe.html
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http://7xcnc.com/
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http://www.mini-lathe.com/CNCmlrs.htm
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http://www.cncfusion.com/Links.html
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Ken.

[SteveHGraham]

Thanks for the info. So my hopes of describing a part orally into my cell phone and then coming home to find it already made may be a little unreasonable.

The 7xCNC link is really good.

[GlennW]

So my hopes of describing a part orally into my cell phone and then coming home to find it already made may be a little unreasonable..

Just wait for the iPhone 6.

[hammermill]

Steve as I understand Ethernet connected systems offer higher communication speeds and the ability to run w.o. the pc being connected
http://www.bevelcutting.com/ethernet-cn ... c-et1.html. here is a Ethernet controller.

[ctwo]

Steve, just wait for the luxury of machining from the comfort of your living room la-Z-Boy to wear off...

[ivatt260]

Steve;

I've been using my little Unimat CNC lathe, as my larger almost-completed lathe looks on.

I've put in some "conversational programming" bits in to my LinuxCNC config - taper turning, etc, etc. I also have CamBam, which has a Lathe option.

But, I generally just code in GCode. It's not like a mill, where you are doing complicated shapes.


eg, latest bits for model safety valves; looks kind of like a toilet plunger; long handle 2.3mm diameter, then 2.7mm for a shorter bit, then 5.75mm for 6mm long.

One subroutine, set starting point, end point, starting diameter, ending diameter, and call the GCode subroutine. 3 calls to the subroutine, and parts done. Subroutine simply turns to a set distance along the Z axis, to a set diameter, exactly as you'd do if you were doing this manually.

As I don't part off in this lathe (no power nor rigidity), I take bits out and hacksaw them.

2nd operation is to face ends (plungers turned around, and in lathe chuck); take the turning subroutine, modify it to take the starting Z position from it's current position, and turn to 0mm diameter. I put the tool close to the part in the lathe chuck; the "take from current position" means that it'll face parts with varying lengths, all to the same finished length, without wasting time, or having a tool dig-in.

3rd operation, drilling for a stainless ball will happen in another lathe, one with a tailstock.

[SteveHGraham]

I had to look Unimat up, because I was not sure what sizes they offered. I thought they had stuff up to maybe 8 x 18, but it looks like they're even smaller than my Big Dog. So I see why you're not parting. I have tried parting on the Big Dog, and it was a very weird experience. The bar flopped around like crazy.

[sncf141r]

I had to look Unimat up, because I was not sure what sizes they offered. I thought they had stuff up to maybe 8 x 18, but it looks like they're even smaller than my Big Dog.

Much, much smaller. In addition, the one I have is one of the first, so it has a short bed, and a motor barely strong enough to turn the spindle! So, doing brass/bronze is literally a case of "whittling" the material away.

My bigger lathe that will be CNC'd is a lot stronger, with 3 phase motor (so I can easily change the speed via software).

This little one goes to exhibitions, etc, so is really only for display. Your larger lathe will be much better.

I am tempted, however, to put the sensors on it for threading; we'll see...

[hanermo]

My opinions and experiences..
For lathes, and perfect threading, you need a good motion control board, and a servo indexed spindle, or an encoder on the spindle.

All other options have failed to work well.
I have about 2000 hours of work invested in lathe threading, with mach3.

Some observations:
Steppers dont do the pullout fast enough.
Normal sensors dont produce a good enough signal for single index signals to work well.
The signal must be crisp, and it must work at various speeds, so you can thread at 60 rpm (large steel pieces) and 1200 rpm (small alu or steel pieces).
Only servos have high dynamic range - ie they are accurate (needs high resolution), and fast, at both low speed and high speed.

I am fitting a CSMIO-IPS 4 Mhz motion control board, from Cslabs, and ac brushless servos.
My step size is about 0.2 / 0.3 microns on the lathe.
With a 10.000 count encoder, thats 300 kHz at 3000 rpm (servos), and at 1:3 with belt drive, thats 1000 rpm at screw (x and z).

I also feel that direct-driving steppers, especially on a lathe, is far too inaccurate.

Servos can work, obviously, as industrial users do so.
However, they use very accurate, quite large servos, and very accurate (very rigid) couplers.