Re: [ATM] Minimum Inner Tube Diameter

[ntent <ntent@pctcnet.net>]

If I'm not mistaken, the rule of thumb for a tube is two (2) inches 
greater than your primary mirror diameter. Wouldn't this be applicable 
to a truss scope? Although, using the principle below, the "2-inch 
principle" is indeed larger:

"For a 16" F/4 this gives 0.087*64" = 0.55".  So, the radius of the 
upper ring is 8"+0.55" = 8.55" or 17.1" diameter.  I might round it up 
to 17.5", for a little more breathing room."

Thinking on it, a larger solid tube diameter would be preferred so as to allow for better cooling and possibly less convection.  I'm no expert... just recalling old posts.


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