The worm, gear,
and housing are precision and very German. The brass gear has a trough-cut
helix, and is centered on the Mirror Box Axle Shaft by a simple bearing.
The worm is steel with a 3 to 1 interleave and rides on thrust bearings
at either end. The brass on steel allows you to adjust the worm pressure
for Zero Backlash without binding because of the natural bearing property
of dissimilar metals--particularly brass. The Aluminum Housing
for the Worm has been cut in half to allow for easy removal of the Mirror
Box. The worm is driven by an in-line reduction gear connected by a vibration
dampening coupler to the stepper. The preferred Gilmer Belt
is Nylon-Kevlar. Note the Mirror Box Axle detaches with 4 Hex Allens
from the fork end. Overall gear reduction is about 800:1