Eric, I would not think it was the encoder at this stage, especially if the error is repeatable, the 50 thou error I suspect may be due to backlash?
If you use an encoder cable with independant pairs, it is customary to use a twisted pair for the A,/A & B,/B pair etc
The shield should only be grounded at one end, Usually the amp input end as this is usually closer to the main cabinet gnd.
Due to noise problems I had on one installation, I have been using belden 9891, I believe this is an ethernet cable, but it has one pair which is larger than the other conductors which I use for the power pair. I have had no problems since with any of the retrofits I have done.
Is your encoder on the motor or on the final motion actuator, i.e. ball screw or slide?
Al
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CNC, Mechatronics Integration and Machine Design.
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E. |