Re: These servo motors worth a darn?

Jon Elson wrote:

> Ugh. Not a whole tol. I'm assuming these must be pretty small
> robots.

Fairly small, X and Y axis will end up with about 12" travel. Robot was
built in 1988, have no idea what was norm for accuracy or speed back
then. Sounds like I'm hunting for motors. Well, just thought I'd ask,
they're already here...
Should have the Glen Tek amps in a couple days. They look older, but
don't appear to be cheapo units. Got them on Ebay for $25 ea, figured
that was an acceptable gamble.

> Generally, these are continuous ratings, so the motor can deliver
> 100 Watts power at the shaft all day, which is not a lot.

Can you reference a stepper oz/in rating for comparison?
I ran the X axis with a 110 oz/in stepper once, holding the motor in my
hand and stretching the belt tight. Got 60"/min out of that little motor
with no lost steps. Unless I score enough parts to complete a servo
setup, will be running the machine with 195 oz/in PacSci motors with
Compumotor OEM650 drivers.
The 100 watt motors sound like they may not even match this setup?

> Putting the encoder directly on the end of the screw with a high
> quality helical coupler is the best way. Then, let the motor
> drive the screw with a toothed belt.

OK, just wasn't sure if that setup would work OK. When I don't really
know what I'm doing, I get paranoid...

Thanks for the help!

Jon