On Fri, 3 Dec 2010 13:41:24 -0600, Ecnerwal wrote
(in message
):


My first attack on this idea came when the Reeves drive control bearing
on Grandpa's "bought it new from the factory and he passed it on to me
while still kicking" Mark V crapped out when I was in the midst of some
turning I needed to get done ASAP.

In either case I'll swap the speed dial over to driving the speed
control potentiometer for the VS motor. Due to availability, familiarity
(I started in on variable speed drives for lathes when DC was the only
common option) and lack of cost (free if you watch the curbs and
advertisements), I'm prone to using Treadmill DC motors - just derate
the claimed HP by about half. ie, a "2hp" treadmill motor is more likely
to be about 1 hp in practice, I find. If not fond of surplus (or fond of
different surplus), the newer and better way is a 3-phase motor with a
Variable Frequency Drive - at the 1&2 HP level there are 1-phase-in,
3-phase out versions that make this reasonable to do in the home shop
(though you'll need 220V for the 2HP drive.) The VFD option is supposed
to have better torque at low speeds, and you don't have brushes to
replace.


Somewhere back in the mists of some archive there should be a posting
from when I first made the temporary external conversion to get the job
I was working on done.





Thanks for the info on the speed control setup you used.
tom koehler

--
I will find a way or make one.