[Joey2point0]

Retrofitting a D&M lathe with a AcornCNC motion controller and am a little weary of how to hook up the DC drive to the motion. However I could just be making a mountain out of a mole hill in my head. Here's what I know:

*The motion controller supplies a 0-10 vdc signal to the spindle drive
*The DC drive uses a 10 volt reference signal and an external 10K POT to control spindle speed

Is it as simple as connecting the motion controllers 10 volt signal to terminals 2&3? (see the attached photos)

Any insight into this would be greatly appreciated!

Thanks,
Joey

[Jim Dawson]

Is it as simple as connecting the motion controllers 10 volt signal to terminals 2&3? (see the attached photos)

That's the way I read it. Looks like pin 2 is the common or signal ground.

[Joey2point0]

Adding the DC Drive manual, if additional information is needed.

[Jim Dawson]

According to the manual schematic pins 2 and 3 form a standard 0-10V comparator input circuit. Pin 2 is common, Pin 3 is the 0-10V command signal.

[Joey2point0]

After a little more research I have good reason to believe that it is not possible and will fry my Acorn. The DC Drive is not isolated from the AC supply.

From a quick search/read KBSI-240D Stand-Alone Signal Isolator should solve my problems but I need to do some deeper digger to be sure.

If anyone with experience can shine some more light on this it would be greatly appreciated, otherwise I am going to move to Acorns Forum since it seems more fitting. Ill report back when I have a surefire solution

[Jim Dawson]

Using the KBSI-240D can't hurt, another layer of isolation is a good thing and will give you piece of mind. If you look at the schematic, the signal lines are isolated from the AC input power by transformer T1 in the drive. 0V does not seem to be connected to earth ground at any point.

[Joey2point0]

Using the KBSI-240D can't hurt, another layer of isolation is a good thing and will give you piece of mind. If you look at the schematic, the signal lines are isolated from the AC input power by transformer T1 in the drive. 0V does not seem to be connected to earth ground at any point.

I suppose I could do a simple conductivity test to determine this, will give it a go when I get home today.