steppers randomly stop as DRO still counts w/video

[evermax]

Hi All

I am new to the forum as I have just finished (nearly finished) my 19x38x8 cnc router after getting the bug last month.

I used electronics from Robotix pre-wired into a case.
Working with Uni-polar Stepper Motor Drivers, PBX-RF, and the RBX-1 relay board to turn on the Spindal (Bosch 2.5hp)

Problem is on occasion, a jog action, would turn ON the relay. This would happen about one out of 10 or so attempts to a jog. When it happens all 3 green led light up on the relay board. The DROs would move in Mach but the motors do stop turning when in this state. Attempting to jog in a different axis will eventually move the motors resetting the condition, turning the lamp and all 3 leds off.

I removed the relay board and my homing switchs to eliminate them from the equation, Below is a vid of the anomaly and pics of the wiring setup and table.

Video
Untitled Document
Photos of the electronics and cnc
CNC relay trouble

Manufacturer first blamed mach3 then windows, so I switched to Linux and EMC2 which changed nothing, its still happens and if the relay board were installed it would trip the relay ON when the drives lockup. Im not an electronics wizard so Im at a loss, hence the reason I went with the plug n pray option and had Probotixs do the wiring. He states its like a big patch bay and not his boards but I running out of things to eliminate.

Has anyone seem anything like this before?
I checked the parallel cable.
Swithched OS and software.
Removed my home switches.

So close yet so far.
Thanks for any help

I will try a different computer later and pule out a parallel port malfunction.

Someone mentioned ground loop but not sure what that is.

Thanks Again

[bobsch]

Start by checking to make sure all your equipment is grounded. Also, are all your control cables shielded?