[ATM] Trombone tuning my bi-Newt

["stU" <stu@aaronj.com>]

I have a pair of Meade 114NT's and I have been working towards making a
bi-Newt out of them. 

This past weekend I made a breakthrough. 

The goal is the have the eyepieces come off a star diagonal at my IPD. How
to do it was the main question? 

I made a pair of 3/4" plywood disks about 5" in diameter that just fit into
the main tube. I mounted the primary on the disks and I slid the 'piston'
assembly down the tube until the fp came out at the right point. Since the
Meade secondary is 15/16" and it is mounted in a 1-3/16" holder, I ordered a
pair of 31mm secondaries to avoid vignetting. 


It is so easy to slide the primary and test the results, that I thought that
I should share my experience. 

My plan is to mount the bi-newt in such a way that I am standing behind the
focuser with the tube open end in front of me for a true binocular viewing
position. 

The bi-Newt is coming together slowly but surely. There are many problems to
be solved, including convergence and IPD adjustment. I will also have to
make a weight balance arm for forward/aft control. 

This is a real fun project.
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