6" F/6 Carry-On Travel Scope
This telescope was built to take on a trip to the island of Kauai, in
Hawaii. It was finished days before the trip and carried on with
no problems in a duffel bag. I made especially sure to have no
sharp points or edges
on the scope! The baggage screeners turned their heads at all
kinds
of funny angles when it went through the x-ray machine, but it went
through
with no questions. I don't know whether to be satisfied or
scared.... I was fully prepared to set it up on the spot!
Here's a picture of the scope, assembled (my 16" F/4 HexScope is in the
background in storage mode), another image of the scope "under
development"
showing the bungee cord better, and a focault test image of the mirror.
Perhaps the most interesting feature is the bungee-cable counterweight.
The bungee cord wraps around a carefully shaped "cam" or "pulley"
that
tensions it to counterbalance the scope,
The mirror was made by me, and turned out quite smooth and accurate.
Performance on planets is excellent, and Omega Centauri and
Jupiter looked wonderful under
the tropical skies.
The focuser is a JMI RCF-1mini, and works well. If I had it to do
over again, I might try the KineOptics helical, since it is probably
lighter. The secondary is unnecessarily large, but I had it on
hand and it was assimilated in the rush to finish the scope before
vacation.
I made the mirror cell from random aluminum scraps. The mirror
sits on Teflon pads. The mirror box and secondary cage are mainly
formed from 1/2" poplar plywood, a lighter alternative to Baltic Birch,
but with a thinner outer ply and slightly less rigid. The "mini
tripod" is built like a stool - the legs screw into the triangular base
and when screwed in tightly the tripod can be used as a chair! It
easily holds my 180 lbs! It is quite stable with the scope on it.
To stow the scope, the secondary cage, light baffle, eyepiece box and
all the thumbscrews (in their own container), and the counterweight
"cam" and bungee cord all fit in the mirror box. The top of the
mirror box hinges shut after the truss tubes are removed. The
side bearings are removed, and the polesl, bearings and tripod parts go
in the duffel bag with the mirror box. The bag can fit under the
seat in front of me on the smaller regional jets, and in the overhead
compartment on larger aircraft.
Aperture fever makes me want to try a larger carry-on scope for my next
trip. We'll see if I get to it in time.
