Motors for DIY generator

[William Baumann]

I would like some input on a few 3-phase motors that I have available to me. I know they are relitively high RPM for what I am trying to do, but I thought I would see if I would be able to make any of them work. Here goes...

1) Baldor Electric Co. 3 phase.. 1a) 3/4HP..1725RPM..Frame 56
1b) 10HP..3450RPM..Frame 213JM
1c) 1.5HP..3450RPM.. Frame 56


2) Marathon Electric 3 phase...1HP..1725RPM.. Frame 56-70


3) Dayton Electirc MFG. Co. 3 phase...
3a) 1HP..3450/2850RPM...Frame F56


4) Rockwell Manufacturing Co. 3 phase...3/4HP...1725RPM...Frame 56YZ

5) Century Electric INC. 3 phase...1HP...3450/2850RPM...Frame J56

6) Magnetek 3 phase...3/4HP...1725/1450RPM... Frame LA56

I was thinking the Marathon (#2) might be the closest as it has the highest HP and lower RPM range, but I am thinking that even at that the rpms would still be too high unless I did some gearing. I like the 10hp (#1) also, but at the very high rpms I think it would be very difficult to make it usable.

I look forward to anyones input. Thanks.

[Stewart Corman]

maybe I am missing something basic here?

there have been many who have taken this route, but I have a very obvious question:

besides the work machining the armature
and the cost of purchasing the expensive magnets for mounting on the armature,
and you still end up with generator that requires gearing to get from 300rpm rotor to 1700 generator rpm ...
AND it may not end up particularly efficient or may cog?

why not just get a new PM 3 phase 460v servo motor from a large eBay surplus dealer such as "hgrauctions"
http://shop.ebay.com/hgrauctions/m.html?_nkw=&_armrs=1&_from=&_ipg=25
he posts about 100 new items per day and one or two servo motors are always listed

I saw an AB similar to mine in 2KW rating go for <$100
specs are here:
http://support.elmark.com.pl/rockwell/Literatura/1326a-2_9.pdf
key items are amps and coil ohms

Stew Corman from sunny Endicott

[William Baumann]

I will check that out, and you make very good points, I was simply trying to use what i had laying arround and wanted to see if it could be made to work is all.

[Steven Fahey]

I've converted several 3-phase motors. I like doing it, and no I don't need gearing. Since you've never done it before then start small, like with a 1-HP motor, then decide if it was worth it and if so, go bigger. I don't convert motors just for the sake of something to do - every one I want to use as a wind turbine. One turns out to be too big for my tower, but I may upgrade the tower in the future.

The magnets for my last motor conversion (3-hp motor) cost less than 200 USD, and I replaced the bearings for 30$ more.

I don't try to compete on price, I want to experiment and make stuff and learn in the process, but I don't consider this route to making a generator to be expensive.

Good luck. Lots of folks reading this forum (and others, of course) are interested in these kinds of motor conversion projects, and if you post details of what you did, I'd enjoy reading about it, too.