Re: Motor calculations? Help!

Jon, I do not see this the same way you do. Don't you think the
continuous current rating is more important than the peak current
rating? 28 Kg-Cm / 2.44 Kg-Cm/Amp = 11.5 amps, a gecko would still
have plenty of reserve. 20 amp limit would still give 49 Kg-Cm. I
wish i had one of these motors for my Z axis.

>Fanuc DC Motor 0 (z axis)
> >Type: 0-2000M
> >Output Power: 0.4 KW (0.5 HP)
> >Rated Torque: 28 Kg-Cm
> >Max. Torque: 240 Kg-Cm
> >Max. Speed: 2000 Rpm
> >Rotor Inertia: 0.029 Kg-Cm-S 3
> >Back EMF Constant: 25 V/K RPM
> >Torque Constant: 2.44 Kg-Cm/Amp
> >Mechanical Time Constant: 25 mSec
> >Thermal Time Constant: 50 Min
> >Weight: 12 Kg
> >
> >
> 2000 RPM needs 50 V plus an allowance for I*R drop. I don't see a
> figure for armature resistance,
> so I can't calculate farther on that. at 2.44 Kg-Cm/Amp, and 240

Kg-Cm

> peak, the peak current is
> 98 Amps!
>
> >Fanuc DC Motor 5 (x,y axis)
> >Type: 0-2000M
> >Output Power: 0.8 KW (1 HP)
> >Rated Torque: 55 Kg-Cm
> >Max. Torque: 480 Kg-Cm
> >Max. Speed: 2000 Rpm
> >Rotor Inertia: 0.05 Kg-Cm-S 3
> >Back EMF Constant: 50 V/K RPM
> >Torque Constant: 4.87 Kg-Cm/Amp
> >
> >
> 50 V/KRPM * 2 (000) = 100 V + I*R. I peak is 98.5 A. I'd think a

150 V

> supply would be
> good here. Hmm, I assume you will be retrofitting a Kearney &

Trecker

> horizontal boring
> mill or similar monster machine with motors like this! These X-Y

motors

> could crank a
> large V-8 engine with no direct drive to the crankshaft! Do you

really

> need to hang a 16 Kg

Wally

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:
> snaketracks wrote:
>
> >This is actually a Pratt & Whitney Tape Mate C. It is not that
big.
> >It weighs about 4500 lbs. These are the motors it comes with.
> >
> >
> OK, well that IS bigger than even a Bridgeport Series-II machine.
> That makes more sense then. But, I don't know if you can even get
this
> machine
> to move with Gecko servo drives. You might look at Rutex, they
have a
> 40 A drive.
>
> Jon