Subject: Re: 3 wire stepper motors
Date: Sun, 29 Sep 2002 23:54:25 -0400
Organization: Storm Internet Services
References: <email@example.com> <1033132989.893377@savina>
NNTP-Posting-Date: 30 Sep 2002 03:54:29 GMT
X-Newsreader: Microsoft Outlook Express 6.00.2600.0000
Sounds like those are synchronous motors you are looking at, not stepping
motors. Superior makes both.
Tell us the model number, should be on the end of the motor. If so they
have a set speed, typically 72 RPM when running.
"Al Hephy" wrote in message
Kevin McMurtrie wrote in message
> In article <firstname.lastname@example.org>,
> email@example.com (Ralph Seguin) wrote:
> >I noticed at a surplus shop some Superior Electric NEMA 34 stepper
> >motors, 120V, 0.3A, 50 oz-in, 3 wire.
> >What is a 3 wire stepper motor?
> >How does one drive them?
> >I have a really small budget ($0 if you ask my wife :-), so I don't
> >think I can afford all the nice servo and stepper stuff.
> >I have a 3 axis stage with 10 TPI Acme screws on X and Y and a
> >ballscrew on Z that I'd like to make into a little mini-CNC mill.
> >I know that 50 oz-in is pretty low compared to some of the 150-250
> >oz-in motors that I've seen, but those other motors are pricey.
> >I was thinking of rectifying 120V AC to 120V DC and using that as a
> >power source, or maybe rectifying 240V AC to DC. Is this a bad idea?
> >Are these motors worth investigating, or should I save my pennies?
> >Inexpensive source for kick ass motors, drives, controllers, ...? :-)
> >Inexpensive source for power FETs?
> >Inexpensive source for rectifiers?
> >Inexpensive source for power diodes?
> >rpseguin AT yahoo DOT com
> They're meant to be driven off 50-60 Hz AC using a capacitor to phase
> shift one of the two coils. They'd probably be a major pain to drive
> from electronics since you'd need 40 to 80 VDC, maybe even 100+ VDC with
> a parallel R and C in series with the motor to limit the holding current.
> Have you looked at discarded flatbed scanners and old hard drives?
....and old printers.