The Siren Board

Hello all,
I was wondering how I would go about shortening two brushes (the ones that turn on the electrical ring assy.) I recently recieved from Federal?

N/A

It depends on how much you need to shorten them, if it's a lot, use an extremely fine jewelers' saw, then smooth it out. If it's a little, just use some fine emery cloth (found in the plumbing section of your local hardware store) Don't forget to have good ventilation when you do this. Carbon dust is not particularly good for you.

Sanding down the brushes seems kind of odd to me. First off, I am guessing you want to shorten them as they protrude too far out past the holders and will not stay in place when you are trying to reassemble the siren. Cause you are looking at the chopper unit and when trying to stick it back onto the collector rings you have these two brushes sticking out too far to where they will not go back into their slots. Or is it a different thing you are talking about? Depending on how far they are sticking out, what you are supposed to do is turn the brush while holding the metal back in place. This will twist the little copper jumper cable inside and pull the brush back. Do not over twist it as you could snap the wire. This will put tension on the little cable, but once the brush is pressing against the rings, the tension will be relieved. Those brushes get virtually no wear and tear on them compared to the ones that run against the commutator on the chopper motor so they should last a really long time. Hope that helps.

Oh also, those brushes are supposed to run with a flat face on them against the rings. The ones against the commutator are supposed to be curved/molded to the arc they are rubbing against to prevent commutator damage.
-Adam

Hey thanks Adam, the brushes twisted in fine. It works now. All I have left to do is bolt the horn on.

there is no need to shorten the brushes. if you bought the right ones, they are specifically made to fit the siren w/o modification.

Adam explained very well how to "shorten" the brush wires.
It's in the Thunderbolt manual. I posted an explanation how
to do it a while back on the old board complete with pics.

there is no need to shorten the brushes. if you bought the right ones, they are specifically made to fit the siren w/o modification.

The brush wires are too long to use in the T-bolt collector ring brush
holders. You have to twist them like in the manual to "pull" them up into the holders. The chopper motor and collector rings use the same brushes.
The brushes have to be up in the holders a bit so they will retract into the brush holders without
being smashed while installing the chopper motor into the housing.