Faulty stepper?

[kong]

I just got my machine wired up, and one of the motors is not turning properly. It will turn in both directions, but will occasionaly lock up. I have disconnected the leadscrew nut, so there is no friction there, but still locks. If I remove the motor and try to turn it by hand, it seems very stiff compared to the others. So is this a lubrication problem, or just a dodgy stepper?

[balsaman]

It sounds like a bearing problem. You could try that motor hooked to another axis.

Eric

[kong]

Nope, I've just tried it wired to a different axis, not even on the machine now, just won't spin. Seems to move a fraction, then stops, then won't move at all. Dare I lubricate the bearing on it? I'm just worried about the oil getting inside?!

[balsaman]

I doubt oil will fix it. You need to take it apart and change a/the bearings probably. The bearings in most steppers are sealed, so I doubt trying to lube them from the outside will do anything. It may be easier to locate another stepper.

Eric

[kong]

Thanks Balsaman, I just contacted the guy actually! Just gotta wait for it to be delivered from the US now!

[WOODKNACK]

Hey Kong.
I just had a stepper do the same thing! Then my Z axis blew a chip! Maybe it was a bad chip. Thank god Jeff at Xylotex is a great guy. He said to just send it to him and he'd fix it. What service! Cant beat that!

[kong]

Thanks woodknack, but it's the motor. I tried it wired to different axis, and it still won't run at anything over about 4 IPM before losing all torque and jamming up. The other two steppers are lovely. Damn, that xylotex board is good! I'll probably just put that stepper on the z-axis for now until the new one comes. Can't wait to get something cut - just gotta figure out all' the software!

[WOODKNACK]

Kong,
What I meant to say is, My motor was doing the exact same thing. I too must have a bad motor. THEN IT BLEW A CHIP ON MY BOARD. I would'nt use that motor. id wait till you got another one!

[kong]

Actually, that's good thinking. I guess the stepper will be drawing more current now to turn it, so could blow the chip. Damn it! i will go check shortly. And i haven't even cut anything yet!

[WOODKNACK]

Kong,
take a mutimeter and check the ohm's on all your a's and b's. If you get to one draw alot less the its a bad chip! oh ya unplug all you power supply to the board and all the steppers first! Let me know what happens!