Hello, i just got my retrofitted hurco cnc mill working.  I have a package from kelling, nema 34 servo motors, breakout board, 320 gecko drivers, 500 line US digital encoders.  I wrote a program using mach3 to run +11 inches to zero 240 times and i lose about .030 from position.  US digital offers a board which keeps tract of exactly the position of the encoders. (It seems) http://www.usdigital.com/products/interfaces/pc/internal-card/
will mach3 work with this card so can be sure i wont lose posiition?  Can anyone tell me a way or something i can buy so i know i wont lose postion?  i already tried to increase the frequency width,  (doesnt work).
Thanks

will mach3 work with this card so can be sure i wont lose posiition?  Can anyone tell me a way or something i can buy so i know i wont lose postion?  i already tried to increase the frequency width,  (doesnt work).
Thanks

Tracking how much position you lose wont fix the problem.  Something is wrong with the way the machine works... closed loop is just reporting it back to you.

I dont recommend using US Digital encoders with any type CNC. Slow the feedrate way down and see if it is the encoders. They should count correctly at slooow speed.