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,

Travel scope Early assembly Focault image

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.
Mirror cell Tripod top Tripod parts Tripod and mount

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.

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