I am looking at other drives becasue the Dugong is not available right now and is back-ordered.

One of the other manufacturers just told me that I needed a larger and more expensive drive because the diameter of the motor is the criteria for the drive, not the rated current.

This is something I am not familiar with.  My servo motors are right under  maximum for their drive.  According  to their specification manual  their driver can handle more than a  20%  over-voltage.

This is confusing. Can someone line me out on this?

Thanks,
JAckal

In my opinion that is only a rule of thumb rather than a fact (rare earth magnets made big differences to motor performance in recent years). However, if you consider leverage then a larger diameter armature will produce more torque for a given current (bit like using a longer spanner when tightening a nut) and therefore should be more powerful.

Just my 2 cents.

Tweakie.

I dont know a lot about DC servos but that all sounds like crap to me. A motor has a rated voltage and current and also a peak value for both is usually given. Drives are likewise and if the drives ratings are big enough for the motor then I cant see how dia has anything to do with it.

Hood

I dont know a lot about DC servos but that all sounds like crap to me

That's what  I was thinking.  But, with my lack of experience, and being new to this stuff, anything is possible. This could have been one of those weird exceptions that just didn't make sense.

 I agree with tweakie on the flywheel effect and inertia. My concern was how they told me  physical size  was more critical than what the ratings that are  on the motor tag.

Thanks a lot guys,

JAckal