[RussellSt]

I have a 1993 Citizen L20 that is having a new problem...Spindle will no go over 2810 RPM...All works well at lower spindle rpm but any call over 2810 just yields 2810 rpm..program 4000 you get 2810.
Inverter is FR-A520-3.7K No alarms happen

Another new problem...sporadically the gang will be making parts fine and then all of the sudden the parts will be .039 to large in diameter...(hmmm 1mm) if I keep running it every part is a little smaller until it gets back to where it was....usually about 50-100 parts...So what I have been doing is take the bar out and cut air for 50 to 100 parts then put the bar back in and all is fine ...this happens every few weeks...
No alarms happen .....Anyone have any ideas?

[rcs60]

I had the same kind of problem with an A32-7 citizens all of a sudden the parts are .025 big the next day or two the parts are small by the same amount
turned out to be the X axis encoder
we checked it out by swapping the x and z encoders the problem with the x axis went away so we replaced the encoder

take a look at your parameters to see if the max spindle speed has been changed
can you call your nearest citizen dealer to ask about the problem

[slidingheadman]

If its the sub spindle the speed is set low if the chuck is not closed if its the main spindle try running this spindle in C axis if it alarms out possible the PLG needs to be replaced