Re: [CAD_CAM_EDM_DRO] Servo torque test question

Robert Allen & Marsha Camp wrote:

> Hi all,
> After having very little luck finding someone in this group
> that has applied Gecko g320/340 drives to a mill the size of
> mine I have decided to try and size servo motors that will
> work on my mill. The question I have first is, can torque
> required to run an axis be determined relatively accurately
> with a string around a drum attached to the lead screw and a
> spring scale pulling on the string at a fixed speed. I hope
> this isn't too dumb a question but I wanted to double check.

All this will determine is the dynamic friction in the screw and way.
You have to add in force required to achieve maximum acceleration,
and force required to achieve whatever tool feed force you think will
be needed. I just pulled a number completely out of the air, 1000 Lbs
of linear force, and then worked back to see how many amps I'd
need to feed to the motor to get that. It was not real hard. This is
for a standard Bridgeport machine.

Jon