Zero the Traversing and Elevation Mechanism (T&E Mechanism)
Zero the T&E mechanism by zeroing the traversing handwheel, elevating handwheel, and the elevating mechanism sleeve to the lower elevating screw.
To zero the traversing handwheel:
- Hold the T&E mechanism so that the traversing handwheel is on the left when looking at it, then turn the traversing handwheel toward you until it stops.
- Loosen the locking nut slightly.
- Align the zero on the scale with the zero on the elevating screw yoke.
- Hold the scale with the zeros aligned, and tighten the locking nut. Make sure the zeros stay aligned.
- Turn the traversing handwheel two complete revolutions away from you. If doing this at night, count 50 “clicks” away from you.
To zero the elevating handwheel to the upper elevating screw:
- Align the two zeros.
- Rotate the elevating handwheel up or down until a zero with a line below it is visible on the upper elevating screw.
- Position the elevating handwheel so the indicator is pointing at the zero on the handwheel.
Zero the elevating mechanism sleeve to the lower elevating screw:
- Rotate the elevating mechanism sleeve all the way up; rotate it down until it stops and note the number of complete turns.
- Rotate the elevating mechanism sleeve up half that number of turns.
- Position the slide lock lever to face you.