Re: [ATM] More on my Mak-Cass project

["Bob May" <bobmay@nethere.com>]

The technique that Meade is using to get blacker fields is to do the conical
baffles and put knife edges inside the baffles.  This gives the best of both
worlds as the cyndrical baffle doesn't vignette the light and the edges
provide the sharp baffling points where the light doesn't just reflect
further down the tube.
The cheap way is probably to thread the inside of the tube although that
will probably be difficult as it isn't down the axis of the bed of the
lathe.  Turning grooves in the tube is the alternative although that will
tend to be a bit tedious unless you do up a special multipoint tool for it.
You do want the edges to be sharper than the typical 60deg. of the threads
but it is allowed to have wide grooves with an uneven slope on each side.
Bob May
http://nav.to/bobmay
bobmay@nethere.com
NEW! http://bobmay.astronomy.net


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