Re: [CAD_CAM_EDM_DRO] What variable speed motor to use?

Chris,
These are new DC permag motors (large) with a K&b Electronics
killer controller. This gives tons of torgue over the entire speed range.
Like I said, I am using these all day long. This is modern stuff, not old
shunt wound SCR stuff. The new full wave triac controllers are unstoppable!
No transformers. Straight AC to DC control.
It is advisable to still use the gear or belt changes for speed or torgue
needs as the requirement arises. Typically I stay at one selection at all
times.
RichD

> > Lee,
> > The "treadmill motor/controller" set sold at Surplus Center
> > 800-488-3407 p/n 10-1806 at $49.95 (No web site)
> > is a great choice for this. I have a drill press and a Bridgeport
> > mill converted to DC and love it.
> > These are industrial 90VDC PM units with full speed range and feedback
> > for torgue. You will have to fab a mounting method as the frame is not
> > standard.
>
> If I remember correctly the treadmill motor develops its maximum power
> at a substantially higher RPM than the typical 1725 rpm of the typical
> 60 hz AC induction motor typically used on a machine like this.
> Variable speed motors aren't great at putting out torque far below
> their designed speed. What I think he really needs is some more reduction
> between the motor and spindle.
>
> But maybe someone has had acceptable results with the treadmill motor and no additional reduction.
>
> Chris
>