Hey all,

I have one stepper motor that likes to run backwards sometimes.
Its on the Y axis...with dual motors.
When I disconnect the the motor in question and the gantry runs smooth...no vibration or change in direction.

When I disconnect the good stepper motor and jog with the bad stepper in one direction on the key board> stop > hit same direction and some times it will go the opposite direction.
Also a bit of vibration.
Any tips or advise?

Thanks

Hi,
sounds like either noise (possible) or a bad connection (probable) to the DIR terminal of your driver.

Can you connect your nominally 'bad motor' to the good driver?

Craig

Hi Joe,
I conected the bad motor to the other Y driver, and it does the same thing.

It has a China # on it
Is this something that can be rebuilt in a local motor shop?

Hers a pic of the motor

Hi,
bad luck...I don't think it can be rebuilt. Some of the service information I've seen prohibits disassembly as it
can permanently degrade the 'permanent' magnets inside.

Craig

Thats ok, Can I upgrade to new steppers?
Should I change both motors on this Y axis?

Thanks for your help


I would think both motors should draw the same amps

Hi,
would have thought that having both motors identical would be the ideal.

Even if you found another motor with the same current rating would the  resistance and inductance of the windings
be the same?

Given that one motor is faulty would you consider another/better brand?

Craig

I'm certain that motor is bad
I lay them both out on the table top
And it vibrates and switchs direction
The other side runs smooth.

I gather I should change them both
I'm ok with upgrading

I find the idea that the motor is faulty with random direction changes almost inconceivable. Stepper motors just don't do that - they can't do that.
I would immediately expect that either the driver is faulty, or the Dir pin connections (between the PC and the driver) are faulty.

Hook the problematic motor up to a different driver and see what happens.

Cheers
Roger

This motor is 1 of 2 on the Z axis.
#1 motor is bad
#2 motor is good

#2 motor connected to #1 or #2 driver motor runs one direction and smooth.
#1 motor connected to #1 or # 2 driver runs but with vibration also can change direction by jogging on keyboard.
I haven't checked parallel port cable