[ATM] New home built 12" ultralight dob

["Alan Scott" <alanne1956@hotmail.com>]

>>I just finished a 12" ultralight dob, and wanted to
>>ask for feedback. Any ideas on how to make it lighter or smaller?
>>
>
>Well for the primary you could have gone to a thinner
>slumped mirror blank of say 1/2 inch plate glass.This
>would have reduced weight and allowed a really faster
>cool down time,given the heat generated in the trunk
>of the car that the 1 1/2 inch glass will soak up in
>transit on warmer days.Long wait for the glass to
>reach ambient,even with a cooling fan.

Ric,
  I could not agree more.  However, this WAS a fairly cheap scope, and I 
purchased the mirror, finished,  for about $475.  They are now mass produced 
in China.  Turns out that it is a great mirror, HOWEVER - you only get the 
thickness that they make.

  I have noticed a bit of a cool down issue - after 9 hours observing, star 
tests under about 380 power still show a bit of a "swim" to the aire disk.  
No idea if it was still the mirror cooling, or in the atmosphere.  From the 
looks of it, I would guess it was right in front of my mirror.  Time to 
start on a fan project.

alan

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