29 replies to this topic

[Terra Nova]

Being most desirous of being able to use my Unitron Unihex dial-an-eyepiece accessory with my Tak FC60 and my Zeiss Telementor T1 I recently set out on a quest for nicely made, anodiz d aluminum off the shelf parts that would allow me to do just that. Having realized a while back through trial and error that the diameter, thread number and pitch were pretty consistent with that of the telescope end of the Vixen 36.4mm Eyepiece Holder thread, I figured this would be pretty easy. And today, I found out that it was. 

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[Terra Nova]

This is what it took to do it.

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Edited by terraclarke, 31 May 2019 - 10:51 AM.

[Terra Nova]

Here it is all assembled.

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Edited by terraclarke, 31 May 2019 - 10:52 AM.

[Terra Nova]

And ready for orbital insertion.

 

Thanks to Manish and the other good folks at Agena Astro!

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Edited by terraclarke, 31 May 2019 - 10:56 AM.

[Richard O'Neill]

Cool.

[CharlieB]

Very nice!  The value of a Unihex just jumped.

[dgreyson]

Ooh! I need to get a Hexagonal Terradapter myself!!

[Terra Nova]

Xavier was selling a nice anodized aluminum single piece adapter like this a few years ago but I just heard from him and they’ve been all gone for several years. Short of machining one yourself (which I did some years ago but sold it with another Unihex) this is pretty much it. The other alternative would be to use a Vixen 1.25” to 36.4mm thread-in visual back, threaded into the back of the Unihex with a 1.25” extension tube placed into it, but that solution was a bit crude for my taste.

[AllanDystrup]

Nice Terra!

 

     Here's another option: a Unihex-to-T2 adapter I had Xavier produce a couple of years ago:

    

    

     If you have a Unitron 1.25" EP holder on your Unitron drawtube (or on any other telescope backend), you can screw in a 1.25" ( or 0.965" or 2"...) T2 nose on the Xavier adapter and you're ready to go; Another option is to put a T2 quick changer on a 1.25" T2 nose, shove it up the EP holder, then put a T2 QC-ring on the Xavier adapter, et voila: a QC Unihex! This is very convenient.

 

     I don't know if Xavier still offers this adapter, -- but you can ask him.

 

     -- Allan

 

Edit: OK Terra, you beat me to it  
Well done!  

 

PS -- ahaaaa, seems the Xavier adapter just increased substantially in price, -- think I've got a couple of those lying around somewhere  

Edited by AllanDystrup, 31 May 2019 - 12:45 PM.

[Bomber Bob]

Here's the one I use:

 

 

It's a single machined aluminum piece that just happened to fit the Hex;  the "nose" fits 1.25" focusers, and a .965" eyepiece barrel fits inside it (I tapped & threaded a hole through the side, and use a tiny thumbscrew to secure the chrome barrel).

[Piggyback]

Great news, Terra.

Now a Unihex can be utilized on a Telementor. Can you please provide a pic with the parts listing so I can follow suit? I am dying to try this on my T1.

[starman876]

That is great Terra.  I can now sell all the Unihex's I have with a 1.25" adapter.  Thanks

 

They did make a model with a drawtube that fit 1.25" focusers, but they are hard to find. 

 

[Terra Nova]

Great news, Terra.
Now a Unihex can be utilized on a Telementor. Can you please provide a pic with the parts listing so I can follow suit? I am dying to try this on my T1.

Stefan, the parts list is shown in my second and third images above. Here they are again. The three parts all came from agenaastro.com

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Edited by terraclarke, 31 May 2019 - 08:20 PM.

[Bomber Bob]

The first adapter I made for my Unihex used a part from a vintage 1970s Tasco photographic kit:  A large disk that threaded into the Hex, and had a male .965" threaded bit, that connected a long tube with a terrestrial lens -- made the refractor view correctly oriented.  All I had to do was use the barrel from an eyepiece, and it was good to go.  

 

My current adapter uses parts that are easier to find, and fits both focuser sizes.  The 1.25" part is made in China, and is sold on eBay.  I bought several with the idea of adapting my vintage Japanese scopes that use two focuser tubes (a 30mm manual / pull tube + a shorter 36mm rack & pinion tube) to standard 1.25".  I misread the ad, and thought a 1.25" eyepiece could fit inside, but that was actually the barrel's OD... oh, well.  At least they work with the Unihex.

Edited by Bomber Bob, 31 May 2019 - 08:31 PM.

[Terra Nova]

Here was my first one:

https://www.cloudyni...pter/?p=5440698

But I like this new modular unit much better and it is easily adapted to my Zeiss T2 visual back.

[Jim Curry]

Brilliant, thanks for the details.

 

Now we have to put you on the trail for adaptors for the Super Unihex….

[roscoe]

Cool idea!!  My plans are to bore out a 2-1.25 adapter on a lathe to accommodate the existing nosepiece on my Unihex, but that needs to wait till my son finishes rebuilding his lathe.....

[Terra Nova]

The key piece is the Baader Takahashi / Vixen M36.4 Male to T2 Male Camera Adapter # T2-03 available from Agena Astro for $28 USD.

 

https://agenaastro.c...03-1508039.html

 

This takes your standard Unihex to a Universal T-thread which allows you a myriad of options to adapt to all kinds of systems. The outer end is a male T-thread, which, if need be (as in the case of my combination above) can be converted to a female T-thread using a gender changer such as the Blue Fireball Gender Changer: T / T2 Female-Female Thread Adapter # G-TF available from the same vendor:

 

https://agenaastro.c...anger-g-tf.html

[Bomber Bob]

If I choose my 6 eyepieces carefully, I can leave my Big Accessory Case in the shed, and bee-bop around the yard toting just the scope:

 

[roscoe]

So there seem to be two sorts of Unihexes -  the ones with the T-shaped cuts, and the ones with the U-shaped cuts to secure the EP's.... can anyone tell me if they have model designations, or which one is older?  Mine is T-shape.....

[Terra Nova]

The T cut is older and always is associated with vertical (block) lettering. The U cut started in the 1960s and is generally associated with slant (italic) lettering. Same with drawtube visual backs, diagonals, and porroprisms.

[Tiredeyes]

Does anyone know the size and length of the 2 screws on the side of the Unihex that the Baader adapter fastens to?  When I use the Baader adapter, I only get about 3/4 of a turn before the adapter hits the top of the 2 roundhead screws.  This might be enough, but I'd feel better with about 2 turns.  If possible, I would like to replace the roundhead screws with flatheads.

 

Thanks.

[jwarner191]

Hi, I just got a very old unihex and finally was able to free the turret so it can again rotate. But I wonder, what holds the EPs from falling out? I might be missing some pieces.

Edited by jwarner191, 09 September 2023 - 09:24 AM.

[jgraham]

The eyepieces are held in place with a friction fit. There's usually a small tab built into the collar that acts as a spring. Note that eyepieces from this period weren't very heavy.

[jwarner191]

hmmm, I was afraid you might say that! I need to sell this thing