Centroid Community CNC Support Forum

Hi All,

I have a C3 Mini lathe (7 x 14) that I had recently converter to CNC using Acorn. Its been working great. I would like to add spindle control to it. The lathe has a 230V DC motor that runs at 350W - 6000 RPM. I want to be able to add speed and direction control to the spindle. I would like to hear suggestions on the best way forward for control hardware. If I have to replace the motor, that will be fine as well.

Thank you.

Take a look here:
viewtopic.php?f=60&t=1594

Hi. It can be done. Here is a video that may give you a few ideas: https://youtu.be/fs44aTeAkhk

Here is another video that you may find interesting: https://youtu.be/xIQZ8dCUcwg

Long story short, the DC motor controller in the Asian mini lathes and mills does something strange with the ground. I've burnt up several pieces of hardware fumbling through that problem. The KB boards provide true signal isolation and prevent the ground loop from happening.

I hope that helps,
-Franco

Thanks for both the replies. I had read that thread about kbic and I have seen Franco's and Marty's videos. I am not clear about direction control. I see that kbic with proper isolation boards will provide speed control on a DC motor but what about direction? If I want to do rigid tapping, cnc12 should be able to stop and reverse the spindle. Is there a way to achieve that with kbic?

Thanks.

Go read this thread. Looks like the KB Electronics KBSI-125R controller and the KBSI-240D Signal Isolator are what you need.
viewtopic.php?f=60&t=1305&hilit=Spindle ... Fcontactor

martyscncgarage wrote: ↑Sat Sep 28, 2019 8:29 am Go read this thread. Looks like the KB Electronics KBSI-125R controller and the KBSI-240D Signal Isolator are what you need.
viewtopic.php?f=60&t=1305&hilit=Spindle ... Fcontactor

Thanks Marty. Looks like this might work. Just need to figure out the connections with acorn.

Here is another thread on the subject that has a schematic to show how I hooked mine up.viewtopic.php?f=60&t=1594&start=10

martyscncgarage wrote: ↑Sat Sep 28, 2019 8:29 am Go read this thread. Looks like the KB Electronics KBSI-125R controller and the KBSI-240D Signal Isolator are what you need.
viewtopic.php?f=60&t=1305&hilit=Spindle ... Fcontactor

Those are the exact items I’m using on my mini lathe. They can be found for a very good price on eBay. Using Milton’s wiring diagram in the link he provided makes it very easy to wire up and it works perfectly!

DICKEYBIRD wrote: ↑Sat Sep 28, 2019 12:16 pm Here is another thread on the subject that has a schematic to show how I hooked mine up.viewtopic.php?f=60&t=1594&start=10

This is perfect. Thank you.