[AndrewCNCRP]

My Y axis motor is fluttering badly ie- If I jog with the pulse wheel in thou I get one thou - ok, two thou - ok, three thou massive stuttering, four thou ok, five thou ok, etc.

A friend suggested it may be a bad tachometer on the Y motor, and I happen to have several spare motors (which are no good, otherwise I'd just swap them) which have potentially functional tachometers.

I am wondering - has anyone successfully cleaned a tach and eliminated this sort of problem? Has anyone successfully replaced a tach from a different motor? Is there anything I need to know besides basic disassemble - reassemble? Is there an orientation to the tach like the resolver? (I don't think there is...)

Thanks!

[ianagos]

Are you sure it’s the tachometer and not the resolver? The resolver is an easy switch. No clue on the tachometer but calmotion I believe does sell replacement tachometers so they must be interchangeable.

[ASIGuy]

Yes, they are replaceable and we sell them all the time. We also use them in our rebuilds. Give us a call and we can get one out the door to you today. The part number is MTR-0090 and we have plenty of stock.

As far as the problem goes, I would tune the motor and see if you can tune out the stuttering. This is usually from a bad resolver which is the feedback device on DC motors. We have them as well with a part number of ENC-0008. Pull yours out and spin the shaft by hand. See if it turns rough or has much end play or side to side play. If so, replace it. This might solve the issue. Also, check your motor brushes and commutator to make sure they are still long enough to not short out and the commutator should be clean with no shorts from winding to winding.

Take a look at these things and email me back if you need more help.

FadalCNC.com Tech Support
[email protected]
208-888-9236

[AndrewCNCRP]

Thanks ASIGuy, I'll look into the parts you mentioned, hopefully that will do it!