CNC lathe conversion

[Pete92]

Hello,

I reacently posted about converting my mill to CNC control, I have now got that pretty much planned out.

I am just wondering is converting a lathe any different as to parts required?

Any advise on the subject would be much appreciated.

Cheers,

Pete

 

[Tin Falcon]

If you have done a mill IMHO a lathe should be relatively easy to convert.

tell us what lathe you have and I expect someone can help.

I converted a small taig like lathe and just adapted the plan I used on the mill.
Tin

 

[Pete92]

I have a Warco WM180. its a few years old now, and parts and the acme screw and nuts are getting a bit tired.

Is it just the stepper motors and such or are there any extra bits i need?

 

[DICKEYBIRD]

You'll need a spindle speed/index sensor if you're planning on doing any threading, a good spindle speed controller or VFD, a very accurate homing sensor on at least the X-axis and a QCTP system that repeats well...oh yeah, ballscrews too.

Make sure to post lotsa pics of the project.

 

[Pete92]

Any particular parts people have used?

 

[Tin Falcon]

if you have not done so you may want to read my getting started in cnc thread and the build thread for my lathe and mill projects.

you will need the stepper motors a way to mount the motors and a connection between the motor and the drive scews. either a timeing belt and pulley system or a direct drive with a coupler. A coupler can save the motor in a crash as well as make up for small misalignment in the system . you may want to add thrust collars and thrust bearings.

 

[DICKEYBIRD]

Any particular parts people have used?

Pete, here are a couple of the parts I mentioned above. If you're not electronically challenged like I am, You can buy just the opto sensors for dirt cheap and make your own circuitry but I knew better than to even try. Both of these worked flawlessly straight out of the package for a reasonable price.


http://www.cnc4pc.com/Store/osc/product_info.php?products_id=129

http://www.ebay.com/itm/Optical-End...109?pt=LH_DefaultDomain_0&hash=item19d6e2c0c5

I used a CD (painted black of course) with a hole drilled in the edge attached to the spindle to go with the C3.

The opto was used for the X-axis. I went the extra mile to get very precise homing because I think it's important on a lathe, much more than a mill. My X stepper motor is double ended so I made a half-circle disc to go on the rear shaft to trigger the opto. I put a N.O. mechanical micro-switch in series with the opto and connected them to Mach so that the opto homing signal is ignored until the X-axis gets near home and the micro-switch closes, allowing the opto signal to get through. This gives a very precise homing signal due to the ratio of the stepper motor reduction belt drive and the ballscrew pitch. This allows precision & repeatability when changing tools in the QCTP using Mach’s tool table. That's my plan anyway as I'm just now finishing the set-up of 4 or 5 different toolholders and an ER16 collet chuck mounted in a QC boring bar holder for drilling.

[FONT=&quot]I have another one of the above linked optos on the Z axis but used it without the added stepper indexing since the Z isn’t as critical as X. Once you have homing set up you can use Mach’s soft limits to reduce the chance of crashing. (Yeah, RIGHT!)[/FONT]