Re: Declining motor torque with lower voltage.

Good post Ron, could you do us 1 more favor and tell us the max rpm
your servos are rated for...

Wally



--- In CAD_CAM_EDM_DRO@yahoogroups.com, R Rogers <rogersmach@y...>
wrote:

> With all the discussion about servo power. Someone needs to and I

may when I get time. Do some testing and just find out how a few
different sized motors react under different circumstances. Simple
sheave mouted on shaft with a cable that lifts a weight. A variac to
vary the DC voltage. I'm guessing for X and Y on a Bridgeport that
even a nema 23 sized motor of considerable power would suffice. With
the proper ratio any servo would work. It just boils down to the
rapids that will be achieved. It just doesnt require all that much
power for X and Y. In my case, I'm using 40 lb-in motors on X and Y
with a 2.5:1 ratio and they are way overkill. I can run roughers all
day in steel and the motors never even get warm. Which shows they are
doing nothing more than basically freewheeling. Driving the knee for
Z on the other hand is a totally different situation. Drilling holes
all day, the 40 in-lb motor with 2.5:1 on the knee reduction gets
warm, not hot but very warm. So, I conclude using a

> 2.5:1 ratio driving the knee that a 40in-lb motor is a perfect

size with 60 ipm rapids without gas springs or counterweights. A
smaller servo may work for this but it will generate more heating and
may cause problems and only be suitable for short periods of service.
Unless the reduction were increased proportional to the smaller
motors size with slower rapids.

>
> Ron
>