Tackling starter rebuild this weekend!

Okay, doing the starter rebuild this weekend if my rebuild kit arrives. Just have one question. When I’m lightly sanding the commutator. (3000 grit) do I sand it down it’s length or in a circular motion, or does it make a difference? Thanks in advance.

 

Around the axis. Be careful, and make sure that all you are doing is removing corrosion and any light scoring. Sanding too far will require re-cutting the mica between each bar. Oftentimes you only need to clean the commutaor with a hard art eraser.

 

Thank you. The commutator doesn’t look bad actually.

 

YouTube should have plenty of videos on rebuilding a starter or any dc electric motor or generator. Even an aviation manual can tell you the correct way to bed the brushes.

How many on here have used a growler? There used to be one on the bench in every auto garage.

 

No wonder those mechanics couldn't turn out quality work - a bunch of drunken morons.

 

Growler

 

Where I'm from, a growler is a big ol jug of beer!

 

where i'm from its a pork pie.
stu

 

Good tip!
Put the shaft end near the commutator in a drill press on low, use a very fine file, cleaning often, to even out the contacts, then hit with scotch brite.
After, use a pick to clean out the grooves lengthwise, smidge of low temp grease on busings and washers... Presto!

 

I don’t think you should put a file to it. Just use fine garnet paper.

Use an ohmmeter to verify none of the commutator segments are shorted to the shaft.

 

Especially if your changing brushes, you want to even the commutator as mentioned above.
It wears convex. ) ( emery paper wont correct this and its harder for the brushes to seat, plus they dont make proper contact. ]) ([ Filing solves this, giving you more power and longer brush life ][ ][
Just dont forget to clean the groves, they will build up with copper dust and short out the starter.
Then, rub wit scotch brite, blow dust out, like new.

 

To add, if you are ever in a starter, when you are done its a good idea to hook up the starter NOT turning the engine and spool it up a few times NOT under load, this not only tests your starter before you put it in, but better seats the brushes and shims etc you just messed with.
(Use Booster cables on the floor even)

 

When i recently checked my starter, it barley had black marks on it, i just rubbed it with scotch brite quick and hit it with an air gun... Done

 

I believe emery cloth is a no no, IIRC. Garnet paper because it isn’t conductive. There are quite a few ways to ruin the commutator. That would be a shame if it just needs a little cleaning.

 

Correct. Emery is made from naturally occuring form of aluminum oxide, but often silicon carbide is substituted. Both conduct, so having any bits left in the starter is a not-so-good thing.

 

Emery cloth, garnet paper, silicon carbide tungsten alluminum oxide alloy carbon impregnated whatever...
All im getting at is that any form of sanding is never even, if scotch brit cant clean it, a super fine file with the armature rotating is the only way to get an even, flat surface.

 

Unless you ahdere to standard practice and glue the paper to a flat block.
You can (well I can, you might not be able to at home) turn it on a lathe, which will eliminate the possibility of your hand not keeping the file (or block) flat to the armature.
Many ways to skin a cat, and so long as one takes care in setting things up all will be well.
Checking the armature for linear flatness with a straight edge first is a good practice as well.

Most of the time none of that is necessary though. Carbon brushes are very soft, and starter motors only see intermittent use, so little if any wear will occur on a rarely ridden motorcycle.

 

crocus cloth is suitable for use
"Unlike sandpaper or emery paper, crocus cloth is a super-fine, cloth-backed soft abrasive that doesn't "shed" particles during use, and is just the thing for burnishing and polishing of copper electrical contact, like the alternator rotor and starter motor commutators." XJ4ever.com

 

Well, I finished the rebuild and installed it and hit the start button and got sparks and a poof sound. Uggg! Guess I will be looking at ebay today for a new/old starter.