[monkyspunky]

Hello, I Am currently converting an emco 120 lathe.
It has a Chinese cnc controller, simalar to fanuc system.

I need to buy a stepper/driver combination for the lathe but I need some help choosing the best route.

The axis force from the brochure states 10n force.
Then ball screws are 5mm pitch, and the motor ball screw has a 2:1 ratio where the motor turns twice for every rev of the ball screw.
The machine max rapid speed was 2000mm/min
So I guess if I've calculated correctly, the motor would turn at 800 rpm at max rapid. I have no clue what the motor torque should be?

So my question is should I buy nema 34 4.5nm closed loop stepper/driver?
Or should I buy nema 34 8.7nm open loop steppers with dsp drivers?
Or should I buy 4.5nm open loop steppers/dsp drives, and close the loop to my controller using an encoder?
Or just simple and cheap 4.5nm open loop system?

These options are all I can physically fit in the space available.
Ideally I'd like to increase the rapids a little without compromising performance or reliability.

Many thanks
Lee

[smokediver576]

Hey MonkySpunky,

I don't have an exact answer for you but was curious. You stated that it's using a non Emco controller, how did you get the tool changer to work?

I have a PC Turn 105 that I'd love to convert over to Tormach PathPilot control but the ATC is a huge issue.

Thoughts...