Re: [CAD_CAM_EDM_DRO] Constant torque motor

Doug,

Several standard commercial servo drive & motor combinations have
commanded torque capability. The Emerson FX490 drives on my mill have this
capability... The DX/FX490s are probably larger than you'd want (3hp), but
the principle is there.
PacSci drives have it (PC800s, SC900, from their specs) , and probably
most other servo drive OEMs. Maybe not the cheapest way to go, but it may
reduce future maintenance problems.

- Keith

> I just quoted a job wherein I planned to use air motors to drive take-up

reels on a tape dispenser. The take-up reels peel the backing off the tape
and get it out of the way. Air motors have nearly constant torque at low
speed down to locked rotor. We would set the inlet pressure just high
enough to maintain constant torque.

>
> The client likes the design but doesn't want air motors.
>
> Bummer:(
>
> What about using DC motors with current limiting power supplies? Will I

fry the brushes if the rotor is stalled for a long time? I'm thinking of
using big motors and driving them to maybe five percent of rated current.

>
> Those Minarik DC drives would be perfect for this - overkill but dirt

cheap. I just ordered two yesterday to fiddle with. They raised the price
to $56.95.

>
> Doug
>
>
> [Non-text portions of this message have been removed]
>
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