[Drakkmore]

Hi Folks,

I posted this elsewhere but this looks like a more appropriate spot.

Not many threads on this topic, and not for a long time. Maybe someone can lend me some wisdom.

I recently purchased an old D&M 5 CNC Lathe.

I converted it to run Arduino Due flavoured TinyG, with the origional stepped drivers, and was pretty dissatisfied.

So I converted it to Centroid Acorn, with TB6600 Steppers and it's working significantly better.

I am trying to figure out if I can control the existing DC spindle motor driver which has a 0-10V input, with the Acorn 0-10V Output.

The question I have is of DC common isolation, is it safe to connect the acorn to the dc drive?

Happy to discuss and share what I know so far.

Cheers.

[Jim Dawson]

That's the way I have always done it. I don't know of any way but to connect the commons together without a signal conditioner. There are isolating signal conditioners available, but normally not required.

https://www.digikey.com/product-deta...227-ND/3595569

[Drakkmore]

Yeah I agree with you. This is the schematic of the driver board. And to me it seems like the DC output from the acorn should be safe. But I saw one guy on YouTube who fried his acorn doing something similar so I am trying to be cautious. Attachment 407712

Sent from my SM-G930W8 using Tapatalk

[Jim Dawson]

Maybe get an opinion from Centroid just to be safe. Based on the schematic, it looks like the analog input is transformer isolated from the world, but has a center tap ground that is connect to 0V on the board. I suspect that the 0V is isolated from earth ground. Just make sure your system earth grounds are wired up properly.

[DICKEYBIRD]

Marty over on the Centroid forum strongly recommends an isolation device when connecting to a KB (or the like) speed control. Having fried a couple BOBs back in the Mach days myself, I took his advice and installed a KBSI-240D isolator board with the KBCC-125R motor control on my ORAC/Acorn lathe conversion. It works perfectly.