wrong guy, but have servo question.

Jon, in you last post you said "Wally K wrote:" the following, but it
was Ron that wrote it. I am using steppers on my system.

Ron is doing a bridgeport type retrofit and has been trying to
determine how much HP he will need to move his table and if his
servos are big enough. And i have been trying to gather information
about his system so we could help.

Personaly i think his servos are to small for this type of a mill but
i do not have any servo experance so i hesitate to just say it as
fact.

I have a few questions on servos that you could clear up for me.
First i thought servos were chopped drives. But it seems that when
people here talk about a servo rated at a certain voltage, that is
the voltage they run it at. Example, the servo is rated at 24vdc.
So they run it at 24vdc.

Second what do the torque curves of a servo look like.


Wally K.

--- In CAD_CAM_EDM_DRO@egroups.com, Jon Elson <jmelson@a...> wrote:
>
>
> Wally K wrote:
>
> > Clifton
> > > Precision C23-L55-W30 series. Published specs are: peak torque
=
> > 430
> > > oz.in., continuous torque = 50 oz.in., terminal resistance = 3.8
> > > ohms, peak current = 20 amp.
> > >
> > > They're advertised as 24V, however the data sheet shows them as
36V.
>
> The IR drop alone at 20 Amps is 20 x 3.8 = 76 Volts.
> If you need peak torque at full speed, you will need at
> least 100 Volts DC into your servo amp.
>
> > > I'm planning a 5/.2 ball screw and 1:1 drive.
> > >
> > > I was initially attracted to them because of the low cost and
> > > advertised high torque. However, not being well versed in the
load
> > > profile for servos, I am now concerned seeing the torque curve
max
> > > out at 200 oz.in.
>
> How can the torque curve max out at 200 oz-in when the motor
> is rated at 430? Do you mean because the servo amps you will
> use are rated to something around 10 A? Yes, you might do better
> with a 2:1 belt drive for this.
>
> Jon