30 replies to this topic

[bertb]

Hereby a picture of the smallest (?) 8 inch F5 travel dobson in the world. All the stuff fits inside a closed box of only 10x10x5 inches. All the stuff means 2 eyepieces, 6 trusses (each 4 parts), a red-dot finder, a cheshire, a shrout and, of course the 8 inch primary and a secundary mirror. Even 3 AA cels (for heating the secundary) fits. And guess what? I am now improving the design because I think it can be even smaller!

Clear skies, Bert

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[jayscheuerle]

Very cool, Bert. Color scheme is fun too. Could we see some close-ups?

[NeoDinian]

Might have you beat...

Here's the "Briefcase" dob...

http://www.cloudynig...ly&item_id=1115

This is a design that I'm planning with my 8"...

[bertb]

The briefcase dob is 18x12x6, mine is 10x10x5 (see picture)

Bert

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[RossSackett]

I dunno, guys. Those scopes look a little bulky to me

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[Lee in Texas]

Wow. A "mine's smaller" argument.

[jdownie]

Wow. A "mine's smaller" argument.

Not an argument at all - reread the initial subject line and your confusion might dissipate.

[Moggi1964]

Great thread showing incredible ingenuity from all of you.

Bravo!

[Dave Chadsey]

Great thread showing incredible ingenuity from all of you.

Bravo!

I concur - great work all!

[reiner]

Hi all,

as the competition is open, this is my contribution
28cmx28cmx12cm (poles and alt-bearings go extra). All at less than 6kg.



more here

[bertb]

Yes Reiner, and that's the challenge (and my challenge to you all): poles and alt-bearings must be fit INSIDE the travelbox. So, you must re-design some parts?

Bert

[marcink]

that's the challenge (and my challenge to you all): poles and alt-bearings must be fit INSIDE the travelbox.

Challenge accepted! Here it is:
http://www.cloudynig...5/o/all/fpart/1

[Roel]

poles and alt-bearings must be fit INSIDE the travelbox.

Check! This is my 8" F/5 travel dob. The trusses are made of folding rulers and all of them, including the atitude bearings will fit inside the box (28x30x13cm) I've seen Bert's telescope in real life (Hi Bert!) and it's amazing to see that tiny package transform into a useable telescope! I still believes he holds the record.

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[Wes James]

These are truly ingenious and amazing projects! My hat's off to you all!

[David Castillo]

All these scopes are awesome I can imagine the look on some wise guy airport security guard when these show up.
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Dave

[Biff]

Wow. A "mine's smaller" argument.

I see no one caught that one.

The trusses are made of folding rulers

How well does that work? If they work well then it's a real sales pitch for the truss design.

[BrianRG]

Wow. A "mine's smaller" argument.

I see no one caught that one.

I did -- gave me a chuckle. These scopes are truly inspirational!

Brian

[refractory]

Now how bout one that opens itself like a jack-in-the-box, and folds back just as easily? Might want to include a crank and a small music box.

Jess Tauber

[Gregg Lobdell]

Now how bout one that opens itself like a jack-in-the-box, and folds back just as easily?

I have a plan for a scope just like this. Hopefully it's my next project. Unfortunately it won't be small, probably an 18" square footprint and 8" to 10" tall when folded, with a mirror of 8" to 9" diameter, focal length 40" to 42". But it will look really cool setting it up.

[NeoDinian]

There actually was a strange "Folding" Dob that was commercially available for a SHORT time.. I remember the video showing the setup. Just a small twist, and it SPRANG up into shape... Folding was just a twist while pushing down, and it folds into itself.

Wish I remembered what the scope was, and the link for it...

[Don W]

I think that was the Johnsonian telescope. They're out of business now. It was an interesting design but very pricey.

[Gregg Lobdell]

There's a review of the Johnsonian telescope here on CN at http://www.cloudynig...hp?item_id=1182

I saw what I think was an early prototype of these at TMSP 2003, http://tmspa.com/History2003.html Scroll down about a third, to the telescope makers section, Sam Johnson, Loveland, CO, Best Workmanship - Professional, 18" f-4.5 Dobsoniam, image: http://tmspa.com/200...Sam Johnson.JPG

[NeoDinian]

That's the one. I loved the video showing it folding.

[Steem]

Bert, how much of the scope has to be assembled before you can use it? And what about keeping it's collimation? I can see the secondary mirror is not attached and those trusses need to be assembled too before they can be used. And what about all the screws? In my opinion, a small telescope needs to be able to build up fast too. If not, then why not de-assemble the wood too and put it all in a bag?

[bertb]

Steem, the travelscope holds collimation very well.
The removable secundary is also not a problem.
But yes, the assembly of the complete scope takes some time (about 15 min) and gives some problems at night. That's why I am building now version 2.0 with a new truss system.
The assembly of this version will be simple. And: version 2.0 will be even (a little bit) smaller and less weight.