Re: Parallel Port to Power Supply Grounding Differential

One thing I haven't seen mentioned here is that the AC input to the
components of the system which includes the PC, controllers, and machine
motors etc, all need to share a common ground, and that is the building
ground.

Each electrical outlet should be tested to insure that it is properly
wired. Two wire extension cords are a no no. When checking frame to frame
grounding, use an analog VOM. A digital will some times pick up transient
voltages and give bad readings. Your ground system should be like a tree.
One point of grounding to earth ground, and only one path to earth ground
from any point in the system. For example, if you use shielded leads to
your steppers, the shields should be tied together at chassis that holds
the drivers, but not to the motor end as the machine frame should also be
tied back to ground. Signal ground and machine ground should be tied
together at the chassis end, IE at the power supply, IF you are using a
grounded signal.

The one path is important as you will set up what it termed "Ground Loops"
which can induce some very intermittent problems, as well as some
spectacular sparks at times if multiple paths to ground are
available. Back in my old Main Frame Computer days, we would survey a
customers computer room and almost always would find ground issues. And
almost always, when the issues were fixed, the problem rate would drop.

I also have a question for the group that relates to this subject. What
kind of cabling do you use, Plugs and sockets. Routing, Etc. I am just
building up my Taig, and am finding the cable issue to be a problem, some
needs to be very flexible, all needs shielding. What AWG sizes do you use
for the motors, IE for 55v 7a motors. How are you routing your
cables. And last does anyone have a source for reasonable priced AMP
connectors?

Don