EXTREMELY strange positioning problem ! A bug?

Briefly, I have rapids set to 100IPM (1.6666 in INI file). A G1 Y0 F100 move to a position and a G0 Y0 move end in MUCH different locations every time!! (over .030" different) I have only tested the Y axis, all this started with a dimensional problem.

Some data, machine is a bridgeport servo mill, 2048 encoders, LCNC ver 2.7.14 with AXIS screen, following error set at .001, max ferror at .0015, backlash set at .001, mesa 7i77 hardware, monitoring Y PID error is x.xx e-5 or x.xx e-6 in position in all cases. ALL tests were done with Y axis ONLY moves of 1-2 inches using a .0005 test indicator in the spindle touching the fixed vise jaw.

Setting the indicator to zero when touching the vise jaw, ANY G1 Y0 move reads dead on zero in position on the indicator. I did it at f25,f50,f75,f90 and most importantly F100. Each time the PID Y error is x.xx e-5 or e-6

Doing the SAME test except using G0 rapid overshoots by more than .030 inches EVERY time !! (indicator has .030 travel and it exceeds that) PID Y error shows same x.xx e-5 or e-6 when in position.

SO........ Why would a G0 Y0 move overshoot badly when a G1 Y0 F100 moves stops dead on every time??????? (rapid speed set at 1.6666 (100IPM in INI file)

HELP please !
George

Can you post your hal/ini files?

Hal and INI files as requested. ( hal file has a fair amount of code for shuttle jogging pendant which although unusual, works great)

Nothing really stands out in the hal/ini files

Are you saying the ~30 mill error is a static error (miscounts/something loose) or just short lived overshoot?

A short lived overshoot should be caught by the following error limits so is it possible this is a mechanical problem?

Found the problem. Stupid operator !

I transposed digits in the MDI window when testing.... resulting in a .060 difference in the command line. THEN kept scrolling back in the MDI window to repeat the erred commands.

Definition of insanity at work ! LOL

Thanks anyway Pete, your support is always fast and great.