feedback error on CSM84

Views: 8769

I have an old CSM84 with the brush motors, model PA130620. ... - Dec 10, 2017 by jmelson  

You should replace the Brushes first. If it continues.. you... - Dec 14, 2017 by Jeff R  

I checked the brushes, there is lots of length left on them,... - Dec 14, 2017 by jmelson  

OK, I think you are right! The one brush I can get to looks... - Dec 14, 2017 by jmelson  

Well, I fixed it. I had resisted taking the motor off becau... - Dec 17, 2017 by jmelson  

jmelson

#79444

feedback error on CSM84 | 10 December, 2017

I have an old CSM84 with the brush motors, model PA130620. I had a few intermittent feedback errors, now they have gone solid. But, I found slowing the machine to 85% lets it run without the error. So, I'm thinking there may be drag on the axis.

The error message is :

252:R feedback error

I assume the :R means the R axis. Does anyone know how to clear this up? Is there something that needs to be lubed that I'm missing?

Thanks in advance for any help!

Jon

reply »

Jeff R

#79485

feedback error on CSM84 | 14 December, 2017

You should replace the Brushes first. If it continues.. you must check the wire continuity back to the controler and possibly replace the Motor

reply »

jmelson

#79486

feedback error on CSM84 | 14 December, 2017

I checked the brushes, there is lots of length left on them, and the springs and pigtails are in good shape, too.

I have been checking various cables, and reseating connectors, but making a resistance measurement from the brush holders back to the servo amp sounds like a good idea.

I'm also going to replace the capacitor in the 24 V supply and on the servo amps, too.

Thanks,

Jon

reply »

jmelson

#79487

feedback error on CSM84 | 14 December, 2017

OK, I think you are right! The one brush I can get to looks fine, the other one is on the back, and there's no way to get to it without removing the motor. Even the front brush was VERY hard to get back in. But, there are rubber plugs that allow you to see inside the motor, and it is FULL of brush and commutator dust! So, this motor is much more worn that I thought just looking at the brush.

I'm going to look at getting a replacement motor. Hope it isn't insanely expensive.

Thanks,

Jon

reply »

jmelson

#79493

feedback error on CSM84 | 17 December, 2017

Well, I fixed it. I had resisted taking the motor off because of the recalibrations that would be required. But, it got bad enough I had to. Under the microscope, I could see copper dust packed between the commutator segments. I removed that, and the machine is back running!

Thanks,

Jon

reply »