I am building a 13.1 Truss Dob. The upper rings are 15" ID and the focuser will be at the bottom ring to maximize the amount of baffling I get from the upper cage structure.
It's nice that a 2 ring structure provides a very strong mounting for your secondary and focuser and for attaching trusses, but I really wish it could complete the all-in-one functionality picture by also providing adequate baffling (whatever that may be).
I say "whatever that may be" because that is really my question. Once or twice I've seen these HUGE figures for cage height to provide true and total baffling which strictly speaking, i'm sure are 'correct'.
I just find a 2 foot cage impractical and not 'minimal' or streamlined in keeping with my design goals (not to mention ugly (in the greek ratio sense) proportionate to a smallish scope like a 12.5 or 13.1"
So what in your experience, is a good compromise? A good call? "enough" cage height so that you don't really need to velco on extra kydex, no matter what the absolute mathematical formula says, what is 'good enough' so that I can keep my cage as small/light as possible and not have to to the velcro on spiel?
Kind of a field-experience, or rule-of-thumb, type question rather than a "Newt says 28.7389" question if you know what I mean.
In short, I need help keeping my cage height down, but also not so low that I MUST use a kydex add on. Is there such a thing?
Thanks for sharing your experience.
Tom.
It's nice that a 2 ring structure provides a very strong mounting for your secondary and focuser and for attaching trusses, but I really wish it could complete the all-in-one functionality picture by also providing adequate baffling (whatever that may be).
I say "whatever that may be" because that is really my question. Once or twice I've seen these HUGE figures for cage height to provide true and total baffling which strictly speaking, i'm sure are 'correct'.
I just find a 2 foot cage impractical and not 'minimal' or streamlined in keeping with my design goals (not to mention ugly (in the greek ratio sense) proportionate to a smallish scope like a 12.5 or 13.1"
So what in your experience, is a good compromise? A good call? "enough" cage height so that you don't really need to velco on extra kydex, no matter what the absolute mathematical formula says, what is 'good enough' so that I can keep my cage as small/light as possible and not have to to the velcro on spiel?
Kind of a field-experience, or rule-of-thumb, type question rather than a "Newt says 28.7389" question if you know what I mean.
In short, I need help keeping my cage height down, but also not so low that I MUST use a kydex add on. Is there such a thing?
Thanks for sharing your experience.
Tom.
