Wanted: New product

Probably I should keep my mouth shut since the present astronomy market seems to offer about anything thinkable. However, lately I have been travelling a bit, and sometimes I really have missed the option to bring a scope with me. I have an 8-inch Portaball, but I realise that it is a bit too bulky to bring along on a two-day business trip.
I would really like more aperture than the Pronto size. I also find the 4 - 5-inch APO stuff and the 7-inch Teleport too expensive.

So here is my "dream traveller scope": I need a 6-inch Dobsonian that can be collapsed to a size making it possible to take it as cabin luggage on a plane. Perhaps a "Teleport clone".The focal ratio should probably be about f/7 - f/8 just to make the scope tall enough to use without a tripod. Optical quality should be good enough to accomodate powers up to 200x, and set-up and collimation should be possible to do within a few minutes. And the price shoudl be below 1000$, preferably less. GOTO, tracking and imaging options are of less interest for me, but maybe I'm not the only person who would find such a scope interesting.

Inge,
Let us know when you have those ready! :^)
Floyd

I am sure Neil would adapt the 6" for longer f.l.
http://www.starbuckets.com/telescopes.html

David

I think there would be quite a demand for such a product; Sky and Telescope has had at least 2 articles on building highly portable dobs in recent years, 6 to 8 inches, and I've known at least two people who have done just that.

I'd love a 6 inch travel-newt! In my daydreams about southern hemisphere travel, I know I want more than an 80mm short-tube refractor to check out 47 Tucanae and Eta Carinae!

Well, 6" f/4.5 could be made carry-on even with a solid tube (very carefully), but any longer it would be a problem. I'm eyeing my Meade SN6 f/5 -- about 6" too long (and the focal plane already sticks out 6.5" from the tube). Had it been f/4 like the others in the series it would have been short enough. If you don't mind 40% central obstruction or vignetting, you might move up the mirror in a commonly available 6" f/5, and eat up the extra in focus with a suitable correct-image prism/mirrors of some sort (or a binoviewer).

A retractible/telescoping OTA would be neat, but someone needs to come up with a design that's inexpensive to manufacture. I agree it shouldn't be that hard -- mainly finding some kind of tube that's 7"ID, and another kind of tube that's 7"OD (you know what I mean; if anyone has an idea please holler).

You can buy the truss carbon fiber 8" Uti for under $3K. Looks to me like a better option than the PortaBall or TelePort for exactly this reason -- airline portability. Perhaps Infinity Telescopes can sell a down-scale one for $1K?

Most people who voted with their wallet, bought a C8 or similar. With a Reducer/Corrector and 2" diagonal/EPs, the FOV isn't half bad (still not RFT).

As for how big a Dob can fit airline carry-on 9x14x22, well the answer might surprise you (it surprised me). What do you think?

Finally, one more idea: fold a 6" refractor. If you think about it, there's no CO issue so the tube can be short (bi-fold, like a newt) or shorter (tri-fold). The bi-fold design has the advantage of having most of the weight concentrated at the top end, where it attaches to the alt-az mount/tripod. The tri-fold design behaves like an unobstructed Cat (which it is), except for color -- not that important for a wide-field scope. Good flats are not cheap, but still well within the $1K budget, especially for the bi-fold.

As for a Dob mount, the company that makes the Compact Precision Telescope (CPT) also makes a mount that folds completely flat.

-- William