Is This Good? Late December, 2004
Nathan is prepping the motor. Our adapter plate is on the way, so we need to get this thing ready to install.
Nathan has already removed the motor from the Ohmsmobile. He found this custom dust and dirt filter attached to the motor with duct tape. On the right you see the custom filter, disassembled. While I'm pretty certain it will protect the motor from dust and the like, I'm concerned about heat. Anybody care to say if this is going to be a problem? Should we replace it with chicken wire?As a newbie, I'm not really certain what to say about these brushes. They appear to be concave, as required. There also appear to be some grooves in one of them, visible in the closeup. Is this something I should be concerned about? For reference, I've also included a picture of the commutator. I can't say I love it. Is that streaking normal?
Since Honda motors run backwards from normal motors, I had to advance my brushes in the opposite direction from normal brush advance. But, as you can see from these pictures, my motor only has two sets of holes for the brushes. One is for normal rotation. The other is for dead-center advance. Nathan made a template out of cardboard, using a protractor to measure the appropriate 10 degree advance for the Honda's engine rotation. I think his methods were somewhat ingenious; perhaps I'm easily impressed. Anyway, here's what he said, in (mostly) his own words:
I marked where the holes should go and placed the cap back on the motor, located at it's final location. I placed the bolts through the cap to use as pointers. I used the cap as a guide for the drill bit so the holes would be properly located and straight.
Unfortunately, this meant using an extra long drill bit.
It took 3 hours to obtain the drill bit, a tap, and the tap wrench. I stuffed the motor with rags and taped up the lower holes with packing tape (in abundant supply around here) to prevent any metal filings from getting into the motor.
I was mostly successful about that.
Then I drilled the first hole. First I measured how far the drillbit would have to drill, and marked that on the bit using a piece of electrical tape wrapped around the bit. Then I drilled, stopping frequently to use a magnet to remove the steel drilldust and to spray cutting oil on the bit and down the hole.
When the hole was drilled I removed the cap and tapped it, frequently using the magnet to remove the steel filings. I deburred the hole with a flatfile. I put the cap back on and bolted that bolt in.
Worked great. So I repeated the procedure for the opposing hole.
That one didn't work so great.
The cap doesn't make a perfect guide, so this hole was a little cockeyed and the bolt went in at a slant. I had to use a 1/4" drive socket because the 3/8" drive was too thick to fit between the bolt and the cap. But it did bolt down tight.
With 2 bolts securely in, it was time to test. So I got the battery out of the Honda, rigged some wires as connections, set the motor on it's side and chocked it with a big wrench so it wouldn't roll off the table. I jumped power to my creation.
Nothing happened.
The battery only had 6 volts in it after sitting so long. I also hadn't removed the rags or reset the brushes. So I got the battery and jumper cables out of my truck, removed the rags, reset the brushes, and jumped power to my creation. It sparked and bucked and spun up in a counterclockwise direction.
IT LIVES!!! After silently laughing like a mad scientist I got back to it and made the other 2 holes. Before I put it back together the final time I installed the set screws that plug the holes we aren't using. I'm not really sure why they are there. I figure they are to protect the threads, but you would think the cap bolted tightly over the holes would do that adequately. But it must not, so while I was out buying tools, I bought 4 more set screws and used them in the 4 holes the bolts were previously in. Then I put it all back together and tested it for the final time.
Worked like a champ. The only problem is that the holes aren't perfectly placed and/or straight and I had to finesse getting all the bolts in. But they are within the margin of error and do work.