Re: Is this motor workable?

Well many bridgeport retrofits are using 30lb-in or so servos for x
and y and 40lb-in or so on the knee...But there is a lot of confusion
on this spec as to if it is continuous or not...

Wally

--- In CAD_CAM_EDM_DRO@yahoogroups.com, fj62@s... wrote:
> oops. I think I was comparing 55oz-in continuous to 44oz-in/amp...
>
> I should be starting my own thinking process at the hand wheels on
the
> table/knee instead of at the motor. Assuming I change out my lead
screws
> to 4 or 5 tpi ballscrews is there a "suggested" torque requirement
for the
> screws on a b'port size machine? The knee would obviously have to
have a
> bigger motor or more reduction. Quick side question...is there any
reason
> to change the knee to a ball screw? Seems like there really isn't a
> backlash issue on a knee.
>
>
>
> >
> > That particular motor has 55 oz-in continuous torque and it is
also
> > 6000 RPM. To get the power out of that servo you would need a
> > minimum of 4-1 or 5.6 -1 reduction. More might be better, but
after
> > 5.6-1 the pulleys and belting become a problem. Assuming you
have a
> > 5TPI ballscrew 5.6-1 would give you 214 IPM rapids, that's fast.
And
> > you would have 308 oz-in continuous torque, plenty for a mill just
> > under Bridgeport size.
> >
> > I think for that kind of money you should keep your eyes open for
a
> > servo with same torque but lower rpm…
> >
> > The servos Polaraligned found on ebay would be perfect for your
mill.
> > You could probably run them 2-1 or 2.5-1 and have fast rapids.
> >
> >> Here are the motor specs:
> >>
> >> Torque constant: 44oz-in/amp
> >> Voltage constant: 32.5v/1000 rmp
> >> Peak torque: 600 oz-in, or 37.5 in-lb
> >> Nominal voltage: 40vdc
> >> Maximum voltage: 60vdc
> >> Demagnitization current: >20amps
> >> Terminal resistance 2.60 ohm
> >> Max rpm at 50vdc is about 1200 rpm
> >> No-load current <.51 amp
> >> armature inertia .09oz-in-sec^2
> >
> > Wally
> >
> >
> >
> > --- In CAD_CAM_EDM_DRO@yahoogroups.com, "vortec62" <fj62@s...>
wrote: