Subject: Re: Rewiring FORGE MOTOR (& PB-50 warning)

From: [email-masked]
Date: Tue, 27 Aug 1996 00:19:18 -0400

OK, I am going to open up the wormy can and ask the question - aren't
brush-type AC/DC motors capable of speed control with the cheap little pots
that WWGrainger sells?  I'm not an electrical engineer so I don't know WHY
they work, but for the moment, let's assume they do.  That being the case,
wouldn't a sewing machine motor (I think they are brush motors) work on a
vane-type blower.  It's late, but stay with me a minute, I'm brainstormin'.
 How 'bout if a person built a centrifugal fan (Dave Gingery has a fine book
on how to do it), hooked up a sewing machine motor and put the speed control
on the floor.  Step on the speed control and you get blast!!!  Obviously, you
wouldn't be able to walk away from the forge, but at least you won't burn the
work while your back is turned.  Seriously, though, this might be a workable
solution in lieu of the infamous squirrel cage.

Hollis

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From: Steve Herrick <[email-masked]>
Date: Mon, 26 Aug 1996 21:26:36 -0700 (PDT)

Does anyone have an address or a phone number for the CBA? I let my
membership drop a few years ago and lost the info.. :(

Thanks in advance for any leads....

Hrolthgar -   [email-masked]
           Steve Herrick

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From: "Steven O. Smith" <[email-masked]>
Date: Tue, 27 Aug 96 9:18:55 MDT

> solution in lieu of the infamous squirrel cage.

You are correct. Brush type AC/DC motors are also called "universal"
motors. They commonly show up in sewing machines and vacuum
cleaners. You speed control them by how many volts you feed them with,
quite different from induction motors which track AC frequency.

I'm not sure what you mean by 'cheap little pots'. You could certainly
put a pot (variable resistor) in series with a universal motor to
speed control it. The only trick is making sure that the pot will
handle the motor current without burning up.

The other trick here is that I suspect a sewing machine motor is way
too small to run a vane type blower, at least not a Champion. How
about a blower out of a car?  They put out lots of air. Vary the 12V
DC supply and you vary the speed. Then you can sell your champion for
the amazing bucks folks have been talking about!

--
Steven O. Smith
[email-masked]

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From: Jim McCarty <[email-masked]>
Date: Tue, 27 Aug 1996 10:16:04 -0500

> solution in lieu of the infamous squirrel cage.

Just worked at a forge that had a foot switch on  the blower. Not sure 
what kind of motor it was on. It really was a nice arrangement because 
it let you shut things down when you were using your left hand to hold 
long stock. This wasn't a variable speed kind of thing, just on and 
off. I want one!
-- 
Jim McCarty
Father Helias Forge
Taos, MO
Editor Rural Missouri Magazine
Newsletter editor, Blacksmiths Association of Missouri

³Foolish consistencies are the hobgoblins of little minds³