Re: What variable speed motor to use?

WOW, thanks for all the replies, I am surprised at the quick and
helpful responses.. looks like I'll have to check here more often. I
think I'll give the treadmill motor a shot, combined with changing
the pullies as necessary.

thanks again, Lee

--- In CAD_CAM_EDM_DRO@y..., "Rich D." <cmsteam@a...> wrote:
> 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
> >