refractory
Pooh-Bah
Reged: 02/05/05
Posts: 1337
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I've been scratching my head trying to work out the best overall design for my big binoculars (6" Synta achromats). I'd already decided that folding would be desirable to reduce the length, but it occurred to me a moment ago that perhaps instead of continuing to attempt to keep the main tubes close together (as most/all? designs do), maybe one could have the objectives far apart, like car headlights, with mirrors right behind them deflecting the light cone on a long path laterally before the diagonal/focuser assembly in the middle.
This way most of the weight would be on a horizontal bar perpendicular to the observers face forward. The binos could simply pivot up and down on the bar (perhaps on a variant of a fork mount). It would also allow the viewer not to have to adapt to move much to keep up with changes in the height/angle of the ep's. Think of it as a variation of the old military "rabbit ears" binos.
Thoughts? Thanks.
Jess Tauber
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"Keep an open mind, but not so open that your brain falls out." - Richard Feynman
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BluewaterObserva
Postmaster
Reged: 05/18/04
Posts: 5748
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You would of course lose correct image orientation. Which would be a bummer to me personally. I wonder how those 1080mm/ 7" Russian things work? That may tell you a lot on the best way to go with the project.
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refractory
Pooh-Bah
Reged: 02/05/05
Posts: 1337
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Always could stick prisms in near the focusers to re-right the images without much light loss.
Another idea for mounting would be to have the tubes ride roller bars. Less stress that way per structural unit.
And rather than have the tubes fully stretched out as above, a poster on Astromart suggested folding half-way, reducing the overall lateral extent to some manageable level. But it made me wonder whether there was some way of still retaining the (admittedly probably expensive) behind-objective mirrors, but splitting the two tubes and having them ride over/under like shotgun barrels (each would rotate independently, and the light paths would not interfere, so overall the tubes would look together like a parallelogram.
The focuser assemblies would NOT rotate with the main tubes, and the ep's would be between them- one dropping light down from the upper tube, the other bringing it up from the lower one.
This more collapsed version retains the good qualities, and gets rid of some of the bad ones, of the fully extended one, though it requires more mirrors and fancier light paths.
Oh, heck, this is getting way too involved!
Jess Tauber
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"Keep an open mind, but not so open that your brain falls out." - Richard Feynman
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Glassthrower
Vendor - Galactic Stone & Ironworks
Reged: 04/07/05
Posts: 17931
Loc: Oort Cloud 9
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So how goes the project? Any progress?
MikeG
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Michael Gilmer - Member of the Meteoritical Society & Collector of Falling Stars.
☄ ⒼⒶⓁⒶⒸⓉⒾⒸ ⓈⓉⓄⓃⒺ ☞ www.galactic-stone.com
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refractory
Pooh-Bah
Reged: 02/05/05
Posts: 1337
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Hi. Thanks for asking. I found out a couple of weeks ago that the first of the two lens assemblies, which was chipped a small bit on the edge during shipping, took a bigger hit than I'd thought- shining a bright flashlight through it at an angle it looks like the achromat was split partially (i.e. the cementing came apart) about half way across. I don't know how this would affect the views, since I did use the scope by itself to see what the damage did to the optics, and am no judge of what a Synta lens usually is like in terms of image quality. Anyone on the list know what a split cementing on the achromat will do?
Anyway, I've been looking into getting a new one, and having the insurance on the scope pay for it (they should make their final decisions soon).
As for the design of the scope, I've decided to go "modular", so that I can put the scope together any way I want depending on the mood of the moment. There is an interesting wooden-tube design for sale at Astromart, which I'm thinking of partially emulating. The idea I have in mind is "nesting" the parts (the old fashioned telescoping tube itself) so that one can simply push it back to a compact form for carrying around. The lens assemblies for the bino will be separable and have their own cases.
My brother is often touting how good he is with his hands, so he's been drafted (ha ha) to help with the actual execution.
Jess Tauber
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"Keep an open mind, but not so open that your brain falls out." - Richard Feynman
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