Re: [ATM] New 16" telescope design

["Tom Krajci" <tom_krajci@tularosa.net>]

>From: "Alan Scott" <alanne1956@hotmail.com>

>I have just finished the designs for an ultralight 16"....

>http://www.xmission.com/~alanne/DS4Main.html

Overall seems like a nice design!

You list as one requirement:

"This telescope will be able to carry a half height or full height shroud.
It will also be usable without a shroud for observing during windy nights."

Unfortunately you provide no diagrams/drawings, so I looked at:
http://www.xmission.com/~alanne/DS3-NightScope-1.jpg

Because you use a low profile focuser/focal plane position...you are forced
to use a large baffle disk opposite the secondary mirror.  That will provide
a large wind profile.  Are you sure you want to do that?

See: http://overton2.tamu.edu/aset/krajci/dobsonian/dobsonian.htm
specifically:
http://overton2.tamu.edu/aset/krajci/dobsonian/baffle-train-67pct.JPG
for an example of a smaller baffle disk that's possible if you don't use a
low profile focal plane position.  This presents a smaller wind profile.
(And there are some other anti-wind measures covered on this page.)

Also, why use a shroud?

Tom Krajci
Cloudcroft, New Mexico



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