[Elecraft] APP roll pins

[Jim Sheldon]

 Just a comment on the APP connectors and roll pins.  There are many ways to
solve the problem, some good and some not so good.  Everyone that's used
them long enough will probably have tackled the disappearing roll pin
dilemma at one time or another.

Glueing them tends not to work because most glues don't like shear force
after being applied, and that's what happens when you slide the two halves
of the connector back together after putting the glue on them.  Super glue
is really succeptible to this because it sets so fast.  Other types of glue
have been used with varying degrees of success, mostly poor.

My solution was to clamp the connector halves in a vise, run a 4-40 tap
through the hole and then use a 4-40 x 1/4" setscrew screwed into the hole
to keep them from coming apart.  You can also use a miniscule drop of blue
"Loc-Tite" on the threads of the setscrew to sort of lock it in place --
haven't had one come apart since I started doing this.  

If you decide to try it, make sure you snug the connector in the vise, but
not so tight that you deform it.  Carefully run the tap in and out of the
hole.  Put the 4-40 x 1/4" setscrew into the hole before you remove the
connector from the vise.  Check to make sure the APP will still mate with
another one and hasn't spread from the pressure if the setscrew.  If it has,
remove the screw, reclamp it and run the tap back & forth several times to
cut the threads deeper.  I've found this method works best with a new, sharp
tap.  

Not all APP's are created equal, and some of the plastic material seems to
be harder than others.  Probably depends on what plastic mix was used when
they were formed at the factory.  

Jim Sheldon, W0EB