Scored a PM motor off E-bay

[Phssthpok]

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=280033570919&ru=http%3A%2F%2Fsearch.ebay.



com%3A80%2Fsearch%2Fsearch.dll%3Fcgiurl%3Dhttp%253A%252F%252Fcgi.ebay.com%252Fws%252F%26fkr%3D1%26fr



om%3DR8%26satitle%3D280033570919%26category0%3D%26fvi%3D1

36v, 1125RPM, 5/8" x 2" shaft, 7" long x 4" diam. Almost an exact dupicate of the dead power head that came on my genny/tower. Heck, it even LOOKS like the one that's dead.

The only thing that worries me is that it's listed as being rated at 1.0 amp. Hopefully I can get more out of it than that, but for roughly $30 shipped, I can't really complain as long as it gives me enough power to learn off of. The (dead) powerhead that was on the tower allegedly was seen to put out 10A@24V in a good stiff wind.

It should arrive sometime later this week. With any luck I'll have photo's of it mounted and test spinning on the top section of tower within a week or two. There's a lot of trees around here, but the main powerlines from BPA cut a large swath through them that borders our backyard and, at times, acts like a wind tunnel, so with any luck I'll be able to get a good feel for it's potential/work the bugs out without having to mount it at a full 30 feet. A 10' section is MUCH easier to tilt up and down!

[Chagrin]

For precision motors like these it's not uncommon to see them underrated on the amperage. As to how it will perform is a little hard to determine.

[Slingshot]

That looks like a good motor.  For a 4x7 servomotor, particularly only 36 volts, 1 amp sounds very low.  No-load current would probably be more than 1/2 amp, and my guess is that current at rated torque should be several amps.  I expect you can get 5 amps out of it with relative ease.  You'll know as soon as you get it in your hands and characterize it as a generator.

[Phssthpok]

Well, the motor arrived yesterday. Spitting image of the old one save three differences:

>Only two throughbolts holding the case together instead of four (big deal)

>There's a 90deg brass fitting (vent?) tapped into the case that appears to have had a rubber hose attached to it at sopme point (not an issue since it's inline with the wire leads which will be mounted facing down)

>Front shaft is 3/8" shorter (not an issue) and there's no rear shaft (a good thing as far as I'm concerned as it will be easier to weather seal the rear bearing that way!)

All in all I'd say for $30 I didn't get hurt.

A quick dabble with the Multi-meter netted me the following:

With a good 'hand spin' I could spike about 15v, and JUST break 1A on a spike.

Wrapped with a string, 36+ volts was easily attainable, and I even broke 2A (with a good deal of resistance from the motor)

I have a sneaking suspicion that the motor resistance will help keep the blade speed in check....at least I hope so. As it is I'm going to have to futz around with finding lighter springs for the airbrakes, since it was origonally set up for 24v, and I'm only running a 12v system.

The pisser is that I transported my tower up to a friend's place (2 hrs away) for storage, so as to not clutter up the yard any more than it already is, and since the mount uses sliprings I'll have no way to really play with this thing untill I reclaim at least the top 10' section.