Need Help!- Y axis jumping

[Anthony Dimock]

I have a milltronics Partner 1 cnc machine and the y axis motor jumps real bad unless my feed is real slow or real fast. Called milltronics and they said it sounded like the tach was dirty. I cleaned the tach to the best of my ability but still same problem. It doesnt seem to be losing position so I didn't think it was the encoder. Anyone have any ideas?

Thanks

[nimrod_uk]

Hi - Sorry I can't help with this problem but I have a similar problem on a Pacer Cadet 1220 - Our current problem (and this is urgent - as I work for a sixth form college and it is coming up to Easter when all A level projects have to be completed) is this. The machine skips about 14.5 mm to the right on the Y-axis and starts accurately cutting the pattern at this offset - on one design it skipped for a second time - by the same amount

I am a competent ex-computer engineer who now works as a technician at the college but have no documentation and given the way the machine is housed cannot gain acces to the housing on the right hand end of the gantry which I assume contains the stepper motors etc. without cutting an inspection access into the perspex panel of the surround - I am perfectly happy to do this if I feel I can do anything worthwhile once inside does the machine use encoder wheels or indexing devices or any similar technology for confirming position that may benefit from cleaning?

I would appreciate any suggestions

Thanks - Nigel