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i2i
25-07-2012, 11:56 AM
Hi guys, has anyone rewired a stepper.
I have a triple stack nema 34 stepper manufactured in the 80's, which seems to be breaking down and loses direction and stalls regularly.
I've swapped drivers and tried the same type of motor on the existing driver, so it's definitely the motor.
I've also replaced the original wiring which looked a bit rough.
i've stripped it and tried to make sure there's no crap inside it, and it looks as though the existing insulation on the coils is failing in places. I've also noticed faint traces of rust forming between the core laminations in one or two places.
Any ideas, it would be a shame to just replace this stepper motor.

irving2008
25-07-2012, 12:59 PM
it possible to rewind motors, tho I've never tried it. In concept its simple, in practice I guess getting it right isnt so easy. I also read somewhere that dismantling a stepper can have an adverse effect on the magnetisation of the rotor so you lose a shed load of torque. Here's a thread on rewinding hi-performance motors for RC cars... I guess the techniques are much the same... http://www.xmodsforum.co.uk/showthread.php?t=761

i2i
25-07-2012, 01:25 PM
thanks for the help, after my intrusion into the motor it seems to be as good (when working) as before. It feels as though a coil is partially shorted as there is a bit of physical resistance on part of one revolution. Each of the two coils (windings) has the same resistance of 1.25 ohms, and there are no shorts to the case.

Jon S
25-07-2012, 03:20 PM
Are the bearings falling apart?

i2i
25-07-2012, 03:25 PM
no, they're in great condition

Jon S
25-07-2012, 03:46 PM
carwood.co.uk will take on just about any motor but the cost adds up, paying for UK engineer time verses buying new will be a close call. DIY will certainly be the cheapest way forward but have no advice to give on doing it, like so many things it seems like a reasonably simple process ;-)

i2i
25-07-2012, 06:29 PM
sounds expensive, i'll double check the performance against a good motor and work out the windings.

boldford
20-08-2012, 07:26 PM
sounds expensive, i'll double check the performance against a good motor and work out the windings.Any progress?

John S
20-08-2012, 09:29 PM
I have a triple stack nema 34 stepper manufactured in the 80's, which seems to be breaking down and loses direction and stalls regularly.



Which makes it as powerful as a double stack modern Type 23 :thumbdown:

i2i
21-08-2012, 04:10 PM
Any progress?i've not had a chance to do anything with it.