Motor Brush saga - Success!

First, thanks to all of you who chimed in on this and offered to help. Very much appreciated.

When we last left our hero....

So after hitting all of the easy to get to hardware stores and coming up dry, I finally had a bit of time to do some off the path searching today. A few of the hardware places had some, but not the size I needed or anything oversize, that could be altered to fit.

There is a auto electric place the next town over from where I work, so I stopped by there. Lots of different sorts of DC motors, not just auto stuff. It looked really promising. The guy there was very helpful, but they did not have the size I needed. He took some time and dug around in their odds-and-ends boxes and managed to find one brush that was right in one dimension, and a bit wide in the other. But only one. He was almost apologetic, and he gave it to me and refused any money. I like places like that. Anyhow, I really needed two, (one was damaged, the other worn down to a stub) but he did say he could get them in any size in about a week, if need be. So at least I had an option. I figured that maybe what I had would at least allow me to try the thing out and decide if it is worth further investment.

On the way home, I happened to pass by a Sears Hardware place, and remembered that DT here had mentioned that he saw a bunch of them there. So I turned around and went in, as I had a stripped ratchet to swap there (been carrying it around in the van for months) anyhow. Got my ratchet, and checked the hardware isle. Sure enough, 3 trays of assorted brushes! In the box of brushes for things like electric lawnmowers and chainsaws, I found the exact size I needed. 4 bucks each! The little brass plates at the ends of the springs were different, but I just removed the plates from the old ones and soldered them onto the plates of the new brushes. The commutator on the motor looked a bit rough, so I ran it between centers on the lathe, and did a few light cleanup cuts with a sharp roundnose tool. Cleaned out all of the slots, reassembled the motor, and the thing runs great! I am running this on a KB variable speed controller, and can run this down to maybe 5 or 10 RPM, smooth and strong. When the worm drive box is attached (10:1 reduction) this should work great for the bandsaw.

Thanks again for all who offered ideas and help. In spite of all of the BS, sporge and trolls who just won't shut up, RCM is still a great place!

-AL A

Reply to
Al A.
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Truly excellent! - a good feeling to do something like that, fix something rather than throw it out.

An old electricians trick is to get brushes, bigger, and file them down to size. Messy, but it can be done. You have already figured out changing the contactor caps....

Regards,

Andrew VK3BFA.

Reply to
vk3bfa

Woo hoo! Glad to help. Those small parts drawers in Sears have some neat things, even if they have cut back on them recently. I have one right near me, so I've picked up the odd metric bolt, allen cap screw, various keys, knobs and spacers, etc.

Reply to
DT

It is great to get something like this going. I was going to do that "sand them down" trick, but could not seem to find any that were oversized in the correct way. And boy, it IS messy!

Thanks, AL A.

Reply to
Al A.

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