Steppers stalling at a certain speed

[themule]

Hi - I would appreciate some advice. The x and y axes steppers on My Boxford 190 VMC whine and jerk and stall, but only at a feed rate of around 800 mm per min (say 750 to 850) - all other feed rates have no problem and run smoothly. The motors and drivers are originals with a breakout board added. Can anyone advise where I should start to diagnose the issue? Cheers and thanks in advance. TheMule

[RICH]

Are you meaning  just at or near that feedrate or anything above it?

RICH

[themule]

Fine below and above - up to 1500 which is the limit of the machine. It's just that narrow range that is the problem.

[Tweakie.CNC]

If it's 'mid-band resonance' there are 'easy to make' mechanical devices that can be fitted to the steppers if there is room. There are also electronic solutions as built into the Gecko drives etc.
There is much information on this subject both here and on the Zone if you do a search.

Tweakie.

[themule]

Ah - that makes sense and exactly matches the symptoms I am seeing. Now I know that resonance is the issue I can progress. Many thanks