Re: [CAD_CAM_EDM_DRO] Re: Moog: Servo for Z?

blown_mgb_v8 wrote:

>I've been looking at ballscrews and trying to figure out how to
>calculate torque from linear pressure. Example, a 5/8" dia ballscrew
>with .200 pitch, if I'm calculating for 200lbs of downforce how do I
>get from there to the torque figure needed to drive it?
>

See http://www.timgoldstein.com/cad_cam/motor.htm
I put this in the FAQ some time ago, it goes all the way from the motor
to the
linear force on the table. You should be able to pull out the
conversion for the
ballscrew. The key is that the ballscrew converts rotary motion to
linear. Any
other mechanism that converts the same rotary to linear movements will
have the
same mechanical advantage. Therefore, a drum with a string wrapped
around it,
which has the same circumference as the lead of the screw, is equivalent.

Jon