[ATM] My 20"

["David Williams" <dwilliams1128@earthlink.net>]

Hello

Everyone my 20" telescope is a very nice project, but I still have some problems.  Recently I tried to use it to look at the moon with.  But the tube was too flexible.  Because the front end was pointed to the moon as there was a sag in the middle.  So I talked to a physicyst named Jerry Barkley who works at the Glen Oaks Community College at Centreville MI and he advised me to strengthen the tube by using longitudenal (length wize) pieces of wood not only the circles or rings (you can tell and see that I have used a ring or plywood to act as a baffle and as a stiffener).  And he says that I should notch the lengths and rings together and when it's in good shape use liquid nails.  

Is this good advise?

So basically I haven't seen anything with my telescope except what I showed you guys with, the trees.  And I need more info and knowledge about figuring and parabolizing.  I know that a spherical mirror doesn't reflect all the light rays to the similar plane as much as a parabolic mirror does.  But my friend Jerry (another Jerry) who made some telescopes says that that's the reason that the trees aren't coming into sharp focus.  And the contrast isn't good.

Is that right?

Also I wondered about the floating point mirror cell.  I see that you guys say that the mirror, my mirror isn't mounted right.  But I don't understand how a floating point cell works and why it works.  And what's the advantage of it.  So far I've seen people using a sling to support one side of the mirror, but it looks like the mirror could fall forward.  And if you use silicon to hold the mirror that isn't very sturdy.  The mirror could come free of that.  Also I don't know what is PLOP.


Thanks to you all.
Bye
David
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