Bridgeport VMC 1000 22 - spindle not oriented

Hi all,

have searched through the many many posts regarding similar issues, figured its time to actually post my issue

have a 1994 BP VMC 1000-22 with a heidenhain 2500 controller, simodrive 611's

the spindle rotary encoder is heidenhain ROD 420.0000 1024

having intermittent issues with the spindle orientation being picked up

If i unplug the rotary encoder and test it i can see the signals from all 3 channels

when plugged into the BP while its already on it will see the encoder signal, if I switch off the machine and back on it wont pick up the signal

have tried to chase potentially old wiring but seems to have a clean signal all the way to the board.

can anyone suggest a troubleshooting sequence to assist in narrowing down the issue

cheers,

so far I've now tested the control board with a scope and I can see the encoder signal going in on A,B, 0 channels with a clear marker for every rotation,

checking the spindle drive unit simodrive 611a 6sn1135 I can see voltage in relation to rpm, although the voltage is very weird on M3 vs M4, on M4 i can slow the spindle down to 40 rpm and i get a clean input analogue voltage on .035 v if i push the rpm up to 60 i get a voltage in of .053v on m3 if i set the spindle rpm to 40 i get -.04v and the spindle barely spins, if i set the spindle rpm to 60 i get +.061v

does this give any clue to as to the issue?

Cheers,

Adam

Semi FIXED

the spindle motor drift setting on the Siemens simodrive 611a is located on P.015 once this was adjusted so that the spindle with S0 M3 was near zero rotation the spindle encoder worked again on M19 and M06.

only issue now is the encoder is reading 360 degrees over 3 full revolutions rather than on 1 revolution.


I am trying to work through this issue now