[TheForge] Electric forge blower

[Paul N]

Wow, that pdf looks like it's loaded with good information. Thanks for 
posting that. I'll be doing some reading...

**paul

On 6/18/11 12:28 PM, Paul wrote:
> 1 PSI is roughly equivalent to 28" of water coulomb, which is what wc
> represents. 16 Oz/si would equal 1 psi which equal 28" of water coulomb.
>
> Reducing the voltage on a AC synchronous motor will reduce the rpm, but
> it can damage the motor unless it is designed to be speed controlled.
>
> A better solution is to use a AC/DC universal motor, IE: one that has
> brushes. These respond very nicely to variable speed controls.
>
> see:
> http://www.solorb.com/elect/solarcirc/pwm1/
> http://focus.ti.com/download/trng/docs/c2000/TI_MotorControlCompendium_2010.pdf
>
> They also work with scr controllers like the cheap ones at HF.
>
> I found an old champion blower and after a through cleaning of the
> commutator, it runs great.
> A quick Google search for dc blowers didn't turn up much that was useful.
>
> The higher static pressures that a coal forge requires are the result of
> a larger diameter blower wheel, a squirrel cage blower is designed for
> large cfm's at lower pressures, and often will not easily overcome the
> back pressure in a forge as easily as a proper blower... that's why the
> hand crank blowers have a large diameter blower wheel.
> I have been looking for a cheap source for 115v dc fractional HP motors,
> if I find some I will post them here.
>