RE: [CAD_CAM_EDM_DRO] Bridgeport Boss stepper motors question

> -----Original Message-----
>
> Hello, I was hoping someone here would know:
>
> 1) The steppers on the bridgeport boss mill look like size 42
> steppers but have large finned heatsinks enclosing the body of the
> stepper motors. Did they run these stepper motor harder that typical
> so as to need extra cooling?

They were run as a unipolar system and are rated at about 1100 in/oz.
They were designed to be run as hard as they were run. Meaning, the
machine was designed to run all day long and stepper motors get hot.

> 2) I do not see any current rating for the motors, what is the rating
> for the motors. Will these older stepper motors run OK with PWM
> chopper drive?

If I remember correctly they are rated at 12 amps or so. Yes they run
fine on chopper drives as long as the motor is in good shape.

> 3) If the motors are upgraded, can the motor heatinsks be easily
> removed and mounted on the replacement motors?

No and there is no need for them. Modern motors are designed to run just
fine without the heat sinks. If you have to go through the expense of
replacing the motors consider putting on servos with some Gecko G320/340
drives. You performance will be much better than the steppers. I know, I
had a bad motor on Bridgett (my Bridgeport series II).

Tim
[Denver, CO]