How much backlash is there in the actuator unit?
The 1800/9000, 4800/9400 and 2800/9800 Series units must be considered separately, as the normal backlash will vary due to different constructions. For the 1800/9000: In this unit there is a normal backlash of .005″ to .008″ in the lifting screw thread,-plus .002″ to .003″ backlash in the load bearings. Therefore, the total backlash is .007″ to .0 11″. This backlash is due not only to normal manufacturing tolerances, but to the fact that we must have some clearances to prevent binding and galling when the actuator unit is under load. Usually, the backlash is not a problem unless the load on the actuator unit changes between compression and tension. If a problem does exist, then the 4800 and 9400 Series with the anti-backlash feature should be considered. 4800 and 9400 Series: This unit can be adjusted for screw thread and bearing clearances to a minimum of .0005″. Some clearances must be maintained to keep torque requirements within reason. As the inside thread of the worm gear and the
