I was hoping to report victory on the telescope rebuild, but I'm just surrendering.
I cut 51 inches out of the middle of the tube:
And yes, it took 19 pounds of it.
But the cutting process wasn't pretty, and neither were the results:
Worst of all, when I was done I had the same problem with the lower cage that I had with the aluminum one -- too flexible. I am beginning to think that this is a variant of the 50 pound bike theorem. In case you aren't familiar with it, it was first explained by a friend (okay, a gal that I was convinced that I was madly infatuated with in 12th grade, before she went to MIT), based on the problems of bicycle retention in the Boston area:
1. A 20 pound bicycle is so valuable that it requires a 30 pound lock and chain to keep it from being stolen.
2. A 30 pound bicycle is in less demand, so it only requires a 20 pound lock and chain.
3. A 40 pound bicycle is barely worth anything, so a 10 pound lock and chain are sufficient.
4. A 50 pound bicycle doesn't require a lock and chain. Who would steal it?
This reflects bicycle and lock technology of the 1970s; today the situation is probably somewhat different. But I think the problem here is similar:
1. A big Newtonian reflector will either be heavy and stiff or light and floppy.
2. You can have a big reflector, but you either need a $6000 mount, or it is so hard to keep in collimation that it doesn't matter what mount you put on it.
Perhaps I should just make a Dobsonian mount, and give up on using this astrophotography. Or perhaps I will just sell the parts to someone who has more energy to devote to building a Dobsonian.
UPDATE: CloudyNights has the ad here.
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