If you have access to a steel recycler look for DC motors from industry equipment.
Better and cheaper if you can find them :)
I played with treadmill motors, and the ones I got are DC, mostly around 90-180Vdc ones. They do work, but they have brushes to wear out, probably many will be brass bushings not bearings ect. They can be usable, but better motors exist and can be found fairly easy cheap.
At the recycler I have been getting industrial DC motors for cheap! I pay about 12-16 cents a pound for motors.
Some of these are brush types but they are large heavy duty brushes. Most have nice large bearings too, nice for long life.
I just got some EFKA DC 3 phase motors for a couple dollars each from old sewing machines (probably T-shirt company) and these have no brushes to wear out and nice heavy bearings to last a long long time. Probably a ready built gennie just add blades :)
The Efkas I bought from a new place I found right before I went to Canada to visit Picmillian so I haven't tested much yet. On the milling machine at 300rpm only 2 wires I light a quartz driving light about half brightness, at 900rpm I thought I was going to blow it out. That seamed pretty good power for only 2 of 3 wires and connted direct, no rectifiers!
Using all 3 wires on rectifiers and a 12V dc fan as a load, the fan spins about as fast as I spin the motor by hand. Pretty slow, but it's making more power than most the treadmill motors I played with so far and at a far lower speed. I'll test it better soon.
Now that I am home I plan to get it up and flying hopefully later this week. Just got home about 5AM Sunday (other places to go on the way home)
Personnaly I am not messing with treadmills much, I will take the motors when I find them nearly free but that's about it. I am just finding too many larger better DC motors at the scrap yards right now. I got 2 larger brush types with heavy bearings also when I picked up the other Efkas before I left. They were from some kind of pumping equipment, one is complete and working, the other I have to make an end for since one end was cast into the pump it was mounted on. Same motors so if nothing else I have extra parts for one if needed. For a bunch of motors at the scrap yard (about 7 including 2 smaller ones) I paid about $10 at this new place I found. So if you have the places to look and the time it's worth the effort to do so.
Smaller scrap yards are probably better than the big ones for getting stuff, it just depends really if they want to mess with it or let you poke around yourself.
Most motors have a name plate that will show it's AC or DC, amps, volts, HP etc.. I have found some it's missing from or can't read. Often I can tell by just touching a steel wrench or such to the case, if it feels sticky then it's probably a DC permanant magnet motor, but they aren't always sticky. I don't think the EFKA motors are?
If they can be spun and you have a meter handy or maybe a test light etc.. easy to test if they make power. Alot of what I am getting is mounted to equipment and I have to take it off before I can spin it, so if I can't read the plate I try to test with a steel wrench for stickyness on the case. But I buy most motors now that I find anyway as long as they look powerfull and usable for something. I use AC motors for things too.
And for those interested, Canada was great, and Pic is a great guy too. We did not do much with gennies but lots of other stuff and he builds great log homes, which I learned alot about building myself now. Will post about it elsewhere latter probably.
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nothing to lose
Spelin and tpying are my strong points, not electronics.
