Main Parameters / General Construction Tips
As you can see, the main parameters of this design were:
Compactness when packed. I had to keep the width, height, and length to total no more than 62" (the limitations on most commercial airlines). I ended up totaling out at 57-13/16". I do have to remove my focuser (attached with tiny butterfly nuts), a lead weight (pictured) and my QuikFinder (one-power reflex finder) when completely packed. These items can be packed (with shroud as packing material) in the empty spaces of the nested boxes.
The weight, too, had to be limited to 70 lbs., for the same sort of airline restrictions. It turns out that with the Primary left in the Mirror Box, I total out at a little over 70 lbs. However, when flying, I take out the Primary and carry it on board (even with the protective box I made for it, it still fits within my "messenger-style" bag). The aluminum tubes can be carried on too, or checked in.
I wanted the scope to be sturdy; to survive many hostile encounters with airline baggage personnel and machinery.
I wanted the scope to look good; to exhibit my craftsmanship.
Ease of assembly was important: "No tools" setup preferable.
Ease of key replacement parts was also in the equation... What if the truss tubes were lost in transit, or damaged? Could I easily replace them at "the other end?"
General Construction Notes and Tips:
These "plans" are not for the novice woodworker. No way can I "hold your hand" through every process of making this scope--or one similar to it--via email. You must be willing to solve problems for yourself! And--to repeat--I expect you to already have some woodworking skills, tools, and "dead tree" resources.
Lastly; these notes are not complete; I am outlining the parameters of this design; I am providing you with photos and dimensions; I am telling you what I would have done differently... I am not providing you detailed CAD drawings, a cut list, a plywood cut pattern, or extensive links to sources. All of these things I plan to do in the future: This site is still very much "under construction." ...So please be patient, and do some of the footwork yourself; at least for now.
If you want to use these plans around a 12.5" mirror, I am sure they would work.
Construction material used throughout is: 1/2" Baltic Birch Plywood. This plywood is the finest in the world; the plies are even thickness throughout, and are glued up with marine-grade glue (waterproof). This plywood is, however, expensive and heavy. Domestic "Apple Ply" would be an excellent choice, too.
The Altitude Bearings are made of 3/4" MDF (Medium Density Fiberboard), faux finished to look like aluminum and the bearing surface laminated with Wilsonart's Ebony Star plastic laminate.
The finish is Zolatone: "charcoal matrix."
I worked from the top down, making the UTA (upper tube assembly) first; so that it would nestle into the Mirror Box, then the Mirror Box would nestle into the Rocker Box...
Whenever I needed to, I drew a full-scale drawing on a piece of cardboard. Especially helpful when determining the angle and length of your truss tubes, as well as determining "swing through" clearance for the Mirror Box and the Rocker Box. Also helpful for the mirror cell, both plan (top view) and side section.
I did not worry about the balance point, or where the center of gravity would lie (ideally this would coincide with the center of the Altitude Bearings), for altitude movement since compactness had to be foremost in this design. As it turns out, I had to add a lead weight (removable, as seen in some of the photos)... I melted down about five pounds of lead in a coffee can and stuck a 5/16" bolt in it while it was still molten. A mating 5/16" T-nut was placed in the bottom of the Mirror Box. (See my sub-page "Things I Would Have Done Differently" for a better approach).
I used 3/4" outside diameter seamless aluminum tubing. The tubes are interchangeable, but there is a top and bottom to them. I taped black electrician's tape to the inside surface to help eliminate any stray light. My tubes worked out to be 42" long--but always cut them long first, you can always make longer ones shorter; not vice versa!
Miscellaneous fasteners (photos coming): 1/4 X 20 T-nuts; 1/4 X 20 Threaded Inserts; Hand Knobs (ordered from Reid Tool Supply Company); 1/4 X 20 Threaded Rod (to mate with Hand Knobs using Loctite); 1/4 X 20 Floor Levelers. If you don't know what some of these items are, your local hardware store might help.
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Upper Tube Assembly)
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