Spindle interference with Z axis

[galyion]

Ive been having issues with my z axis repeating. seams to be falling a little every tool. put an indicator on it today and got .015 inch drop over 4 cycles of the z from home to 0. only seams to happen when the spindle is running. i will post a report soon. any ideas???

Machine specs.
pm25mv
procut cnc conversion
dmm servos and dyn2 drives.

[Gary Campbell]

Leave the Z stationary, put the dial indicator on the Z axis, monitor with spindle off, start the spindle, monitor with spindle on. Does it move?


If Z is ballscrew, you can usually grab the coupler and feel the erroneous steps, same for the pinion gear

[galyion]

Ill try that after work today.

[galyion]

when z is stationary there is no movement. i did run z down 5 inches and back to tool check a few times and it lost .015 with the spindle running at max 2500. was only about .002 lost when the spindle is not running. in searching the forum i found i should have my dyn2 hooked up through the db25 connector on the acorn i have it now to the normal screw terminals.

[galyion]

switched my wiring over to the db25 plug and z seems fixed but now i have a new problem. will make new topic