The
coupler at the upper tube ends just below the rotating cages allows
simultaneous adjustment of both tubes while viewing, resulting in very easy
image convergence, even while using high magnification.
threaded
5/8” rods, lock nuts center
block is glued and secured 5/8”
holes are drilled in block at right
and
masonite control wheels with
deck screws
angles to accept threaded rods
finished
coupler – here’s the spot trial
fitting rt/lft tube bracket
which is attached w/deck screws
coupler
and tube brackets installed room to
use two hands to adjust tubes while observing
The
tube brackets for the coupler are drilled with a ¼” bit and the respective
threaded rods are then screwed into the undersized holes, cutting threads in
the wood. The rods are then backed out,
coated with candle wax, and rethreaded into the holes, making smooth working
close tolerance adjusters. The cross
axis block is drilled with a 5/8” bit and the threaded rod is inserted, held by
self locking nuts, again providing a snug fit with no side or end play. The turning “knobs” are ¼” masonite threaded
onto the rods, super glued to rods and self locking nuts.
The
tube which pivots up and down permits left/right adjustment of the tube which
swings left/right, and the tube which swings left/right permits up/down
adjustment of the tube which swings up and down. They serve as indices for each other. The tube/cradle assembly with glass and
accessories attached weighs 75 pounds