Manufacturers Representatives

AXIAL FORCE OF LEAD SCREW

F (mN) when T = Torque in mN·m

L = Lead of screw in meters

F (oz) when T = Torque in oz-in

L = Lead of screw in inches

EFFICIENCY = from 0.9 for ballnut to 0.3 for Acme

Inertia of lead screw load
J = J rotor + J steel screw + J reflected
J steel screw = D^-4 × l × n/32 × Density
     Density for steel = 7.83 × 10⁶ g/m³ then:

J reflected (g·m²) = D^-4l × 7.7 × 10⁵

The reflected inertia of the load is:

J reflected (g·m²) = M (load) L² × 0.025

Total Torque Load from lead screw (T) in mN·m

T = (J rotor + J screw + J reflected) a + T friction

©Copyright 2006, C. Kaufman & Assoc., Inc.. All rights reserved.
Updated: December 2006