[R-390] Cosmos Linearity tool

[Tim Shoppa]

"Jon" <jonklinkhamer at comcast.net> wrote:
> Can anyone recommend the tool for correcting the linearity of a COSMOS PTO.
> I have the PTO   that does not have the tiny screws. They look like a spline
> socket, I have the smallest available one (I think) at 0.032 OD and it does
> not fix. Is they a commercial tool out there?

Is it possible that you ended up with a six-fluted 0.032" spline key?

I bought a "four-flute spline L-key, 0.033" Dia" from McMaster-Carr
(part #7048A11). It was not in stock at the local warehouse and they
had to ship it in from Chicago. It fits but it still isn't easy
work (especially when you've got to repeat dozens and dozens of
times.)

Like Roger I find it easiest to use if I cut off the "L" and put it
in a pin vise. Even then it takes a LOT of skill and patience
to stick it through the radio chassis, through the PTO bracket,
through the PTO can, and into the screw. It was just about impossible
when I was using it as a L-wrench (and I have some experience working
tiny SMT stuff and watches and clocks. Easy to blame on my "fat fingers"
but the same fat fingers let me solder 0201 SMT stuff...). What would
really make a world of difference, if I had one, was a pin vise that
had a little spotlight on the end of it.

The hole in the screw is so tiny that a lot of times it is hard
to get the spline in especially if dust or oil (or worst both!)
are inhabiting the spline socket. When I was degreasing/degunking
my PTO I took out all the spline screws and ran them through my
ultrasonic degreaser.

Tim.