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Frankenbino Exposed II: The BaaDenk

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#1 AstroScience



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Posted 24 March 2012 - 04:33 PM

So, i got this setup, which is the shortest way possible to go with this combination. (Not anymore)
Which included 2" Nosepiece, Baader 1.25" Prism Diagonal (32mm), 1.25" ClickLock Clamp, 1.25" Nosepiece, PowerSwitch and Denkmeier II Binoviewer.
This i had connected to the AP visual back on my 10" SCT and it was amazing combination. Using 24mm Pans it produced me three very useful magnifications.
With reducer arm - x80, No arms - x130 and with Multiplier arm - x220. And what could be better, than to try to do the Messier Marathon with that?
This pair of eyepieces didn't left the binoviewer for the whole night. Of course the lower arm vignetted the field, but it wasn't that horrible,
as i found my self not being bothered by this too much, as all i cared about, was the object him self and there is nothing more to say, that
the ease and joy of using both eyes is simply Stunning!

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Also i had the FilterSwitch laying around and at some point when they all together were laying around my light bulb went ON!
I guess that's what happens when a crafty hands being connected to a head full of ideas.

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The very first thing was to do, is to disassemble the Baader Prism and check if it would be possible to do what i had in mind. And it did.

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Next i disassembled the FilterSwitch and took off this 2" Female Receptacle, which was hold by four small screws on the backside.

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Then i disassembled the Prism by taking off all of the adapters. The eyepiece side male adapter of the prism housing i screwed back
to the ClickLock clamp for the time being. Now, carefully taking my measures, as i had to do this in one shot being lack of spare parts,
i marked the spots for a holes on the prism housing according to the holes of the female receptacle.

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Then using the 1.6mm bit i drilled fours holes on the marks.

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For this project i bought 4 small M2x12 screws with Allen heads. As their purpose were to attach the receptacle to the prism housing,
i had to drill straight thru holes in it using 2mm bit.

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The screws had to be flush flat with the surface of the receptacle, so using the 3.5mm bit i made a recess deep enough for them
not to protrude outside.

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Next, using the M2x0.4 tap i made four threads in the prism housing for those small screws.

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When i was about to assemble everything back, i came upon a small problem. The locking ring of the 2" Nosepiece were too high and won't
let the receptacle lay down flat on the prism surface.

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So i had to give up on this locking ring and ruin it's thread by filing it flat to the prism surface.


And guess what? When attached the receptacle in its final position, it will lay down exactly on this flat filed surface of the nosepiece
and will act as a locking stop, which will prevent the nosepiece from unscrewing under the weight! Simply Perfect!


Now it was a time to assemble everything back and enjoy this masterpiece! Now THAT is the shortest optical path available for this
FrankenBino keeping the PowerSwitch! Using only two thumbscrews of the female receptacle will easily allow to rotate the binoviewer
for better viewing position and you'll have the option to dock the FilterSwitch in between if would want one.


But there is more to it!!! If desire on using it without a PoweSwitch, then simply unscrew it, thread back the dovetail adapter to the
binoviewer it self and use it by docking straight to a prism, like Maxbight and Mark V do. Only now you have the Denkmeier 26mm CA used
in shortest ever combination!


But there is even even more to it! Remember that ClickLock clamp that i had the prism stock adapter left in it in the beginning?
Well now, using the thumbscrews i can remove the binoviewer, thread back into it's place ClickLock clamp with the adapter in it
and return to a mono viewing in seconds, if i ever want to do that at all!


And to sweeten all of this into a bliss - it fits perfectly into original case.


#2 rick rian

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Posted 24 March 2012 - 06:46 PM

Nice job, Sergio! Thanks for posting the images, very helpful.

#3 crazyqban



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Posted 24 March 2012 - 08:06 PM

Isn't that a coincidence, my name is Sergio and I created the original Frankenbino, now Sergio from Israel comes along and creates Frankenbino II. Something about that Sergio name I tell ya. Sergio, that looks great. Good work, enjoy.

#4 johnnyha


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Posted 24 March 2012 - 09:08 PM

Yeh for a minute there I though that WAS Sergio, then I realized it was another Sergio, then Sergio showed up. Anyway that's brilliant!

#5 Eddgie



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Posted 25 March 2012 - 04:54 PM

Very nicely done. I found the 2" powerswitch setup unusable in my C14 due to severe vignetting on the low power switch, even with the 19mm Pans due to the huge amount of back focus required to accomodate the system.

And with the increase in focal length, using the high power are was wayyyy to high.

But you modification is excellent. I looked for a way to easily couple the Denkmeier with and without power switch to the Baader Prism, but could not think of one without machinging something. I would think these modifications would be well within the capability of most people with even small amounts of mechanical ability.

Excellent job. Really excellent.

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