GH1440 Lathe Bed Conversion

[hanermo2]

Any brushless ac servo will be vastly better than any similar sized stepper.
A break will work with a stepper, and any servo, just fine.
Numerous examples.

All my servos (9+) and suppliers (3) offered brakes as options.
A break signal is a std output from the servo connector.

The stepper torque depends on where it was stopped.
E. 3Nm stepper, 200 steps, 10 ustep driver (M542 ( gecko 251)).
== same size Nema 23 1.3 Nm / 3000 rpm / 3.9 Nm peak torque servo.

Your position at-rest vs twist depends on how much torque You have, but in terms of accuracy at 1/10 microsteps you only get the 0.3 Nm from the stepper.

The servo positions to 5.000 points (+/- 0-1-2 counts depending. Often zero error).
In each of 5.000 points you have 3 x rated torque, so a 1.3 Nm servo has 3x 1.3 Nm = 3.9 Nm to bring it back to the desired position.

So the servo has about 13 times more torque best case, and 6 times more torque for positioning typical case.

Real world.
The servo positions to 2000 positions and the stepper to 400 positions.

Servo is 5 times more accurate.

Real world.
Servo accelerates to 3000 rpm in 0.1 - 0.2 secs, real world.
Stepper in 0.5 secs to 600-1200 rpm.
Servo is 5-25 times faster in acceleration.
Depending on application and how you measure.

Real world.
Servo runs 5-2.5 times faster top speed.
Depending on application.

Hmm... do you think these servos with integrated brakes would be more suitable for a C axis than a standard stepper? Can these brakes operate fast enough when machining a sphere for instance, with a ball nose end mill?