Recommendations for stepper motor debug / repair

[Cotswold Woody]

Hi all,
I have a home made (not by me) cnc which I have been using for 5 years with no problems. Yesterday one of the stepper motors stopped working so I only have a y & z axis. The motor makes its usual wizzing & whistling noises but the spindle doesn't move. I am looking for someone, preferably in the Britol/Bath/South West area who could troubleshoot & hopefully fix the stepper. I am wondering if it could be the controller though? Any help, advice, pointers gratefully appreciated. The motor is a Sanyo Denki 103H89222-5241.
Thanks.
Steve

[MikeyC38]

Hi all,
I have a home made (not by me) cnc which I have been using for 5 years with no problems. Yesterday one of the stepper motors stopped working so I only have a y & z axis. The motor makes its usual wizzing & whistling noises but the spindle doesn't move. I am looking for someone, preferably in the Britol/Bath/South West area who could troubleshoot & hopefully fix the stepper. I am wondering if it could be the controller though? Any help, advice, pointers gratefully appreciated. The motor is a Sanyo Denki 103H89222-5241.
Thanks.
Steve

Hi Steve

Just for testing you could swap the y or x axis stepper for the z axis and if the z axis works correctly, then you know it is the stepper motor which is faulty. As far as I know, there is no repair you could do and it would be simpler to replace the stepper with a new one. If the same thing happens then check is the connection between your z axis ballscrew and the stepper motor. This could be slipping. After that, check the stepper motor cabling etc. The standard type of fault checking process. Check every element in the connection from pc to z axis.

Hope this helps.

Mike

[magicniner]

Could be anything.
Photos and details?
Guessing otherwise!

[Cotswold Woody]

Thanks for the reply Mike.
The Z & Y axis stepper motors are a lot smaller than the X axis motor and have 6 wires, where the X has 4, with different wire colours, so it doesn't look like a direct swap. I did disconnect the motor completely from the ballscrew & it was making noises but the spindle was still not moving. I know the forum here is full of enthusiasts who know their machines inside & out, but I use my machine as a tool to quicken up production of parts for my business so I don't mind paying someone to fix it for me, it's just finding someone who can.
I am assuming that the motor is similar to a normal motor so can be tested & fixed - the only replacement units I can find online are in the states & cost $900 - so based on that if the motor can't be fixed then I may just get a X-carve.

Cheers,

Steve

[cropwell]

Highly recommend you check all mechanical connections first. If the motor is 'whizzing' it could be something as simple as a loose coupling.

If you do get to the stage of replacing the motor, you would probably be better off changing the motor and maybe the driver. Without knowing what driver you have, and how it is wired, then it is difficult to advise you properly. 6 and 8 wire motors can be wired in different configurations and I would GUESS that you have a fairly common bipolar connection where the centre taps of the motor coils are ignored.

As Magicniner says - more details please !

[john swift]

its possible the motors OK and the stepper driver has failed and is only driving one of the 2 coils

a quick web search found a new motor at Newark.com for $378

http://www.newark.com/sanyo-denki-sa...ase/dp/20T1472

103H89222-5241 - Stepper Motor, SANMOTION F2, 1.8° per Step, Circular, Bipolar, 13.2 N-m, 6 A, Two Phase, 0.45 ohm


photos & details of the X axis stepper driver will be useful



whats the part number of the Y & Z stepper motors ?

Photo & details of the Y & Z stepper drives will be useful
to work out how the motors are being driven
6 wire unipolar or 4 bipolar with 2 wires not being connected

John

[phill05]

I did disconnect the motor completely from the ballscrew & it was making noises but the spindle was still not moving.

Have you run the motor disconnected from the ballscrew? have you tried turning the ballscrew by hand? first check if the screw turns without the motor if it does then check the motor turns and put some weight on it to make a load on it.
If none of this works then time to buy a new one.

Phill

[cropwell]

its possible the motors OK and the stepper driver has failed and is only driving one of the 2 coils

Or a coil connection wire has broken.

[magicniner]

I am assuming that the motor is similar to a normal motor so can be tested & fixed

If it's just a connection that's externally accessible then yes, but as a rule a dismantled stepper is scrap the instant it comes apart.

[Cotswold Woody]

I've just broken open the controller box to see what type of driver I have & looks like I've got a blown fuse on the board. Hopefully this is the cause of my problem - if it is I think even I cn fix this one!