Re: [CAD_CAM_EDM_DRO] Re: Can my CNC controller blow my motherboard?

No those all need to be connected for safety. But and this is a big but,
the current flow from the drive power supply to the drives must not try
to return through the PC LPT port. The best way to do this is connect
the neg. of the drive PS to the drive neg. input and likewise with the
positive. Stated a different way, the negative of the high current power
supply should be isolated from ground except through the drives internal
ground (for safety). That way, high current from the drive power supply
negative flows to the drive power input and then back to the drive power
supply through the positive.

Mark

mrgamber wrote:

> Yes, indeed, pins 18-25 show a connection to the common ground on the
> controller box which is shared with 120v AC as well as the power
> supply gounds.
>
> Is this the problem?
>
>