7 x 12 Mini Lathe Conversion

[TomS]

This has been done a million times already but I wanted to run this past the forum brain trust before making the purchase. I bought a nearly new 7 x 12 Chinese mini lathe with the intent of converting it to CNC. This is a kit offered by Automation Technologies that I believe fits my needs. https://www.ebay.com/itm/2-Axis-Ste...403686?hash=item2a4b076aa6:g:B5sAAOSw-W5UwaQJ. I intend to run these in direct drive configuration in conjunction with 1605 x 5mm pitch ball screws and nuts. The motors may be overkill but looking at what's available this kit is close on price with offerings by Wantai Motors or Longs Motors. I'd like to hear your thoughts and opinions.

 

[cs900]

those motors will be MASSIVE overkill for a 7" lathe. I think even the 270oz-in motors they offer will likely be more than you need.

https://www.automationtechnologiesi...-2-axis-kits/cnc-stepper-motor-2-axis-kit-sm/

 

[TomS]

cs900 - thanks for responding. Will the 270'S have enough power for drilling in a gang tooling setup? I'm planning on direct driving the X and Z.

 

[cs900]

well there's a lot of factors that play into that question. The key ones being, what material are you drilling, with how large of a drill, and how much spindle torque do you really have? The 270 oz-in motors with the 1605 ballscrew will have roughly 10lbs of feed force

Kennametal has a neat little calculator you can play around with to see what exactly you'll be able to drill given that feed force.
https://www.kennametal.com/en/resou...lemaking-calculators/torque-thrust-power.html

also keep an eye on the torque required as your spindle motor may end up being the limiting factor.

 

[TomS]

I knew there were a lot of factors, just didn't know how to go about it. Got it now. Thanks.

 

[cs900]

you're welcome!