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Some UTA questions

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#1 Piero DP

Piero DP

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Posted 04 August 2020 - 04:25 PM

I am working on a truss 16" F4 dob and now planning the UTA work.
Here are the specs I have in mind:

ID: 17.5"
Ring thickness: 0.5"
Ring width: 1.5"
Sec mirror: 3.1" (this will be mounted with an astrosystems spider + sec. holder)

The design will be classic (e.g. obsession-like).

I am still quite undecided about the UTA height.

Any suggestions, opinions, warnings?

Edited by Piero DP, 04 August 2020 - 04:26 PM.


#2 Pinbout

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Posted 04 August 2020 - 04:32 PM

draw a section of the scope

 

start out with the focuser lined up with the 2ndry

 

build up the spider with stalk height

and then how much above that do you want to extend the uta to help prevent dewing of the 2ndry

 

and then build down from the focuser to block stray light coming up.

 

they can be minimal as you'd like. 

 

you could start off with the height of the uta is same as diameter of the mirror and construct it like above and if the height proportion is off change it.


Edited by Pinbout, 04 August 2020 - 04:32 PM.

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#3 Piero DP

Piero DP

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Posted 04 August 2020 - 05:28 PM

Thanks!

What is the recommended distance for preventing/limiting dew and stray light?


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