Driving a servo

[footloose]

http://www.kelinginc.net/CNC34ServoMotorPackage.html

This package has Gecko 320's, which can do 80V/20A.
The power supply is 72V/20A.

But the servos say "1125 oz-in Peak 90V/40A"

So, does this mean you can basically never drive the servo at peak with this setup?

If so, it seems like most NEMA34 servos can't really be driven by Geckos, (since the catalogs I've seen usually show the peak at higher than 20A) is that correct?

[Al_The_Man]

If you look at the specs the peak torque is 1125 in-oz and the continuous is 226 in-oz.
You normally never drive a servo at peak as this is often the destruction point.
Al.

[footloose]

OK, cool.

So, when you are speccing a machine should you basically design just to the continuous torque?

[MrWild]

Servos spin fast. If you gear the servo down with a pulley, you don't loose rpm at the lead screw over a stepper. So the servo only puts out 230inoz? I bet it spins over 2,500rpm doing it too. If you go 2-1, you have 460inoz continuous, and well over 2,000 at peak. Your lead screw will be spinning at 1,250 rpm or better. With a two lead 10-1 lead screw, you would have 300ipm.

AMC servo drives on eBay can be found cheap if you are patient. I picked up three of them with 30A peak and 15A continuous for just $100 delivered. Less than the cost of a single Gecko.