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View Full Version : Looking for a Stepper Motor...



wmgeorge
04-06-2010, 09:45 PM
I am looking for a 24 volt DC or higher voltage stepper motor NEMA 23 or 34. Going to build a small wind DC generator and can't find the PM DC motor I want so this is my next option. Did a lot of searching today, and found lots of steppers with 2.2 or 3.xx vdc input. Maybe someone here might have a source??

japcas
04-06-2010, 10:12 PM
Check out these.

http://www.probotix.com/stepper_motors

wmgeorge
04-06-2010, 11:15 PM
Thank You! They are perfect, will order tomorrow.

macona
04-07-2010, 06:49 AM
I would get an old three phase brushless servo motor and use that. You will get three phase out and then rectify it to DC with a three phase bridge rectifier. A whole lot better power quality than a stepper.

japcas
04-07-2010, 08:54 AM
Thank You! They are perfect, will order tomorrow.

No problem. Will you be able to show us pics of your project when your finished? Sounds interesting.

wmgeorge
04-07-2010, 09:05 AM
I would get an old three phase brushless servo motor and use that. You will get three phase out and then rectify it to DC with a three phase bridge rectifier. A whole lot better power quality than a stepper.

I thought of the three phase stepper, but did not consider a servo. Another good idea! I really don't want anything more than a 100 watts or so output. Size is a consideration right now as the city is the problem on restrictions on how high can it be. Plan on doing a TV type tripod on top of my shop.

Mike Nash
04-07-2010, 09:38 AM
Check out these.

http://www.probotix.com/stepper_motors

I don't think these are actually rated to be run from straight 12-24VDC. That is more likely the suggested voltage for the chopper type drivers. The actual motor voltage at rated current will be much lower. You are looking for old motors.

macona
04-07-2010, 06:06 PM
a 100w servo will fit on the palm of my hand. A 200w is slightly bigger.

Something like this:

http://cgi.ebay.com/DC-Brushless-Stepper-Servo-Motor-magnetically-shielded_W0QQitemZ120553247384QQcmdZViewItemQQptZB I_Robotics?hash=item1c11889298#ht_1829wt_1156

http://cgi.ebay.com/DC-Brushless-Stepper-Servo-Motor-magnetically-shielded_W0QQitemZ110516140983QQcmdZViewItemQQptZB I_Robotics?hash=item19bb467bb7#ht_1707wt_1156

These are so much easier to turn unloaded than a stepper.

wmgeorge
04-11-2010, 10:55 PM
Well I ordered the stepper motor and did some real quick testing on it before I left for the weekend. What I was looking for was 22 volts or so per phase winding and 3 amps. All at a lower driven RPM so I would not need to gear it up with a belt or chain drive. It did work as a little generator and seemed close to the above.

I also picked up a Harbor Freight photo tachometer on the way out of town. I tested out on a fan while down at the lake and it does work and read correctly.

This week I will mount the motor on a board good enough so I can get some RPM readings while testing the volts and amps out. Just to know the real world RPM's and needed blade size and design.

When it comes time for a full scale one, for down at the lake... I hope I will have enough experience to not make any full scale mistakes!

wmgeorge
04-19-2010, 10:30 AM
Update... Ended up sending the stepper motor back. I had problems getting the amp draw and volts out except at maybe 900 plus RPM/s to fast for a direct drive and not enough output to mess with some sort of gearing.

Ended up with just a salvaged DC motor that I found. It outputs 1 volt for 10 RPM. Made up a little test stand for my lathe and did load testing at different speeds. I can get 5 amps out at about 300 rpm under load, if it gets to 600 it will do 9 - 10 amps out.

So I am trying to get the blade set ordered from TLG Wind power, so far no email or phone response?