Slipring maintenance

[moe1942]

I haven't been able to find any info on when, how and with what to maintain slip rings.

I inherited my Bobcat because the PM wasn't performed by the factory where my son works and the brush wore down to the spring holder and scored the slipring.

I am in the final stage of restoration of this unit and don't want to repeat previous mistakes. I have found sites that show cleaners mounted on wooden handles, but no info on how and when to use them.

moe1942

[ASKANDY]

Basically it's a honing stone on a block of wood. You need to take the slip ring assy out of the unit and just start the engine and redress the rings. If there is enough ring material left, you should be able to do this. If the grooves are too deep, you will need to take the rotor out of the unit and have it re-slip ringed at a motor rewind shop.
Most of the time it's the positive brush that wears out faster.

Good luck....You will need it.

Andy-

[moe1942]

Slip rings

Andy,

Thanks for the feedback.

I did turn the ring down in my lathe but it's at the max. I really want to prevent having to replace the slip ring unit.

The reason I mention this is because I have never seen any mention of slip ring maintenance. Everyone with a engine driven welder might be interested in this subject. This should fall under the category of operator maintenance.

I'm hoping that someone familiar with this procedure, and that may be you, will chime in with details.Mainly what type stone, is it a dealer item, etc.

Also you are right about brush polarity. Found mention of that in my search. Is that a simple matter of swapping the leads at the brushes?

moe1942

[ASKANDY]

Moe,

Do not change the brush polarity! The reason the positive brush wears out faster is that current goes from - to +...Therefore, 70% of heat generated at an arc is on the positive side. It's like pooring water out of a bucket, the bucket gets dryer and your shoe gets wetter
This is also why polarity is important while welding...Electrode positive welding like typical mig and stick is used to consume the electrode, TIG is a electrode negative setup to reduce the heat on the tungsten.
Well I guess I got off on a tangent there, sorry.

Good luck on the rotor.

Andy

[H80N]

Moe
as with many things cleanliness is the key to longevity of these critters... periodically blowing the grit out with compressed air.. wiping the slipring surfaces with an alcohol wipe from time to time will help to minimize abrasive crud... And help to eliminate less conductive material that could promote arcing and thus accellerate wear.. also pay attention to brush alignment and spring tension.. the sides of the brushes will wear in the guide due to vibration.. and can **** in the guide promoting gouging and premature wear..
and if you want to extend slipring life to the absolute max.. you could replace standard carbon/graphite brushes with copper/graphite or silver/graphite... they are expensive but may be worthwhile...
hope this helps
Heiti

[moe1942]

Slipring maintenance

Thanks Heiti,

Good info. I will put the better grade brushes in mine.

Glad to have you back.


moe1942

[LesleyIlic]

Hi glad to say the slip rings are cleaned it was some job(done in the MH).Made my own cleaner out of a part of a large paint stick and 320 paper as Bob had suggested it worked just fine.The brushes were ok but they made that a chore out of removal as they used silicone on top of the cap screws,so the problem stops at the control board as I have checked the voltage reg. and it would appear to ok by Onan's check procedure in the service manual.When I get the new board installed I will report back. slipring

[cruizer]

White comstone takes the ridges off, then I follow up with the brown erasure type stone. If its a deep groove I take the pointy edge of a box cutter and run the engine till its gone then do the white and brown stones.

If its just basic cleaning I use the purple scotchbrite pad.

I don't use a stick, I just reach in and do it.

[H80N]

Resurrection of an 8 year old thread....

[cruizer]

I never look at that date, geezzzz

[H80N]

I never look at that date, geezzzz

not to worry... info is still good... and it helped somebody out..

did surprise me to see it after all these years though....

Just wish more people looked at old posts for answers to questions that have been asked many times before....