ATM Alternatives to Nylon-tipped screws

["Chuck Hards" <chuckh@companionsystems.com>]

I recently made some finder-bracket alignment screws by using aluminum
screen-door thumbscrews (these come in 6-32 & 8-32, with a knurled top for
gripping) and gluing-on a "pad" of flocked paper.  The end of the screw was
flatted first in my mini-lathe, but you can do it by hand with a sanding
block.  The flocked paper "fuzz" flattens out fast, but stays on the end of
the screw and provides paint protection if you don't tighten it enough to
drive it into the finder barrel.  The screws must be mounted in the ring
straight.  If the hole was tapped off-center or misaligned, the edge of the
screw can gouge the paint, especially on longer tubes.  A little chamfer on
the screw tip allows for a teeny bit of misalignment.

Using an aluminum or metal adjustment screw eliminates the major problem of
Nylon screws:  They constantly loose tension, and must be re-tightened.
Sometimes several times during the same observing session.  Owners of Meade
finder brackets know what I mean.

On the 3" finder for our club's 16" Cassegrain, I used standard round-head
1/4-20 bolts for the adjusting screws.  I flatted the head in the lathe, and
lined it with flocked paper.  They were threaded into the rings backwards,
and a plastic hand-knob superglued on the threaded end, now on the outside
of the ring.  The flatted head of the screw is so large (about 3/8") that
the finder tube curves away from it and it only contacts it on a line down
the center, running fore-and-aft.

Chuck