Re: Z-Axis Drive - - Tips and Suggestions

> Ball Screw = 5/8" Dia. (3/16" Radius) with 5 Turns per Inch.
>
> So I first Converted oz/in to Thrust (given the Ball Screw

Specs)...

> (Turns per Inch * (1" divided by 3/16")) = (5 * (1/.1875)) = 26.7
> (I'll call this the Thrust Factor)

The diameter of the ballscrew is irrelevant (efficiency issues and
load ratings aside). No matter what the diameter, one turn of the
screw gives you 0.2" of movement.

Torque is measured in ounce-inches; turning a "crank" with a one
inch radius through one revolution is 6.28 inches of travel. Since
this produces 0.2" of movement, the "gear ratio" for this is 6.28 /
0.2, or 31.4, which is your Thrust Factor, and should probably be
derated by some fraction to take into account the efficiency of the
ballscrew.

Ignoring that, your 40.7 oz-in of torque through a 2:1 pulley gives
160 lbs of thrust.

I would love to know some actual values for cutting forces so we
could tell if that's enough (it sure sounds like it).
Unfortunately, I am unable to find any figures on cutting forces.