Re: Is this Servo good for CNC Router ?

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:

>
>
> clone_enolc wrote:
>
> >I was wondering is the servo motor listed below might be good for a
> >really beefy CNC router? I know it could handle the torque, but

what

> >about the speed? They can use the low-cost Geckodrive G320 and G340
> >Servo drives. What do you think? Any opinions appreciated!
> >
> >Reliance Electric DC Brushed Servo Motors, Model E712
> >37.51 Oz-In/A
> >25.0-30.5 V/KRpm
> >Motor Terminal Resistance .75-1.02 Ohms @ 4A.
> >Maximum Terminal Voltage 60V
> >Maximum Continuous Speed 2100 RPM (No Load)
> >Maximum Peak Torque 1500 Oz-In.
> >Maximum Peak Current 44.5A
> >Maximum Continuous Stall Torque At Max Motor Temp 300 Oz-In.
> >Maximum Continuous Current 8.9A
> >Electro-Craft brush-type DC servomotors
> >
> >
> Holy cow! Yes, it is good! Even at 20 A, you'd get 20 * 37.51 =
> 750 Oz-In.! At 60 V, you get about 2200 RPM. A WONDERFUL
> motor for a big machine tool retrofit. It should work well for a
> router, too. As for speed, it just means you don't have to gear it
> down.
>
> Jon

Jon,

After months of lurking here my mill is coming tomorrow. It's like a
Rong-Fu type mill, but bigger and has a knee. It's called a "Lux
Mill". It has an R8 spindle and it runs on 110, which is exactly what
I wanted. So I take lighter cuts, no big deal. I guess it looks a lot
like a shrunken Bridgeport :)

You said at 20 Amps he would get 750 Oz-In, but the specs say the Max
Continous is 8.9 Amps. Can they be driven like that?

If not, assuming 8.0 Amps is safe, I come up with 300 Oz-In. I still
think that would be OK for my mill. Opinions?

Thank You!
David