Fadal 4020 y axis runaway issues:
Model number 906-1 (4020)
Serial number 9603353 (1996 machine)
Glentek servos and amps.
Machine had somewhat excessive reversal spikes according to the renishaw ballbar program… suspected a bad resolver and changed it out. From then on during power up the machine would runaway for a couple inches of travel and fault out due to over current. Then changed out whole servo for a rebuilt thinking something went wrong with the resolver that was rebuilt for us. No change.
Tried another servo… No change.
Swapped X for the Y axis amps just to check...no change
Swapped axis controller cards…no change.
Sealtight was old and brittle and had to be flexed to remove servo… thinking a wire was broken I replaced sealtight and pulled a new tach wire,checked over the resolver connector and wires…(seemed good). Motor cables seemed good also. Have measured 1.75vac on the lower brass bullet connector on the axis controller card. Have tried many different scenarios of the wiring combo’s for the motor leads to tach leads (i.e. red to black vs. black to black, black to clear vs. red to clear, you get the picture) problem still persists.
Any ideas from the techs on the forum would be very helpful.
Thanks
Perry Brokaw
Plastic Ingenuity Maint Dept.