Factory for a Day. . .

Feb 11. I whipped out the last six truss tube adapters this morning, then drilled through the flat on all 28. Then I made a jig to hold the adapters under the drill press to put a #25 hole through a diameter 1-inch along the turned barrel. I tapped these holes for 10-24 set screws and installed them.

The biggest challenge of the day was cutting holes in the truss tubes. Originally, I planned to drill a large enough hole to provide substantial adjustment. Then I tried milling a slot. Neither effort payed off. Finally I drilled a smaller hole to permit tightening the set screws and a little adjustment. The parts are consistent enough that I think it will be plenty. The best process for the truss tubes involved punching a 3/8-inch hole with the drill press and then cleaning up inside the tubes with a sharp bit in a Dremel tool.

I've finished 8 truss tubes to hold the mirror cell to the center frame and 6 truss tubes to do the same for the corrector cell, all rock solid and nicely adjustable.

I scribed positions for holes in the frames using one of my oldest tools: a set of dividers I bought at Cooper's Office Supply store in Johnson City for my 7th grade mechanical drawing class -- 39 years ago? I'll run #25 holes through there in the morning, then tap until time to run errands. [Middle frame is done.]

After I get the truss tubes attached for plausibility, I'll pull the end pieces off and mill room for the optics. [This turns out to be tougher than it sounds. I'm rethinking how to attach the optics.] Then attach the mounting rails and two sections of Losmandy D-plate, a large one to mate the telescope to the G11 and a smaller section from Bruce Karbal to hold the guider. Then position and mount the focusser.

First light is still a few days away.

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Text & Photos by David Cortner
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