Ultra Compact and portable 12" DOB project

[tostidos]

Hey all,

I recently purchased "The Dobsonian Telescope" by David Kriege and Richard Betty.  Ive been reading it like crazy because I want to take on the tasking of building a Dob. Great read if you haven't read it. Also watching a lot of youtube videos of the different processes. John Dobson has a great video here: https://www.youtube.com/watch?v=snz7JJlSZvw  First off I own a 10" Dob. I absolutely love it but want to make the step to a bigger ap. I Travel a lot for work. as in I deploy to different countries around the world for months at a time and usually in pretty remote areas with amazing skies at night absent of light pollution. I would like to have a scope with the biggest ap I can get and make it completely collapsible.

GOAL:

biggest ap possible (goal is 12" or better)

collapsible to a Stanley tough box size something exactly like this. http://www.homedepot.com/p/Stanley-37-in-Mobile-Job-Box-037025H/202300294?keyword=stanley+tough+box

Now im willing to make some sacrifices on operability and quality. Basically any scope is better than none.

I have plans for the rocker box, Primary mirror box and secondary mirror box. The rocker box will have studs and be held together by nuts instead of screws for repeated breakdown and build up. Ill be able to lay all the primary box boards flat on top of each other. the Entire OTA will be a truss style that can be unbolted. The secondary mirror support trusses will be removable and the secondary mirror box will be slightly larger than the Primary Mirror box so I can slide that tube over the Primary mirror box to reduce space. And the Secondary mirror trusses will have studs and the box will be slotted so I can adjust with wing nuts. Ill also have spacers to fill the slots once the mirror is in place. The only thing I haven't really designed yet is the trusses attaching to the altitude bearing. but im sure I can figure something out.

My biggest issue is the mirror. I want a cheap mirror so that I don't feel bad when someone sticks a forklift thru the side of the box. Ive looked into buying a 12" pyrex mirror and they aren't exactly cheap. even making my own mirror wont be cheap (which I feel im more than capable of doing just time is something I don't really have much of).  Ive been interested in metal mirrors but cant seem to find anyone who makes them. I know glass is the way to go but im willing to sacrifice a little performance on this. Ill be anywhere from warzones to thirdworld countries and first world countries. I don't want to be hauling something very expensive.

I know there is a lot of compromise in this requirement but for my application of travelling I think it will work well. I know a lot of people are looking for portability to an extent like being able to put it in the car. I need it to fit in a more compact area.

My second project I will more than likely be making a 24" dob. or bigger if I can bite the bullet on a large mirror.

Any suggestions or constructive criticism will be greatly appreciated.

Also if something already exists like this that would be great!

Thanks in advance!

Chris

[ronin]

Have a look at the Sumarian Telescopes I guess they are along the lines of what you are contemplating, you may get a few ideas from there.

Someone on here made a very nice smaller version but it will be lost in old posts on one of the sections. It was about 4 months ago and it was a real nice piece of work.

I took copies of the pictures. :grin:

Mirror wise - whose are you thinking of?

Check out Hubble Optics, they do a sandwich mirror and they have an ebay shop on which they generally have 1 mirror at a bargin price, sometimes 12inch seems more often 14inch. The ebay shop is linked to from their own Sandwich Mirror page.

Have a suspicison that just buying a Sumarian could work out easier and no more expensive.

[tostidos]

Have a look at the Sumarian Telescopes I guess they are along the lines of what you are contemplating, you may get a few ideas from there.

Someone on here made a very nice smaller version but it will be lost in old posts on one of the sections. It was about 4 months ago and it was a real nice piece of work.

I took copies of the pictures. :grin:

Mirror wise - whose are you thinking of?

Check out Hubble Optics, they do a sandwich mirror and they have an ebay shop on which they generally have 1 mirror at a bargin price, sometimes 12inch seems more often 14inch. The ebay shop is linked to from their own Sandwich Mirror page.

Have a suspicison that just buying a Sumarian could work out easier and no more expensive.

Very impressed with the Sumerian! Im curious to see the dimensions fully collapsed. But that skeleton of a design is exactly what im looking for thanks!  Price isn't as hard to swallow either.

Hmm the hubble optics 14" isn't a bad price either. Ill have to price out what ill need to buy for my design. might be cheaper than the Sumerian still. But the Sumerian is ready to rock n roll and done haha. Might be able to concentrate on a 24" build at that point.

Thanks for the info!

[ronin]

Keep thinking of doing one myself, but I will likely wait for a cheap 6 inch mirror and make a sort of first run out of that, then scale up in the necessary areas.

[happy-kat]

Real novice thought but won't the carry vessel also have to double up as step ladder? So that you can reach the eyepiece.

Do you have a maximum target weight in mind?

[tostidos]

Real novice thought but won't the carry vessel also have to double up as step ladder? So that you can reach the eyepiece.

Do you have a maximum target weight in mind?

Where I travel to I will have no shortage of ladders and aluminum steps. So im not worried about it. And weight is not really an issue for myself either. Just size. My company takes care of sending things for me and weight is never an issue. Im just authorized a certain dimension. To me the heavier the better (more stable)

[tostidos]

Keep thinking of doing one myself, but I will likely wait for a cheap 6 inch mirror and make a sort of first run out of that, then scale up in the necessary areas.

I was thinking about making the travel dob as my first to see how it goes then decide if I want to go for a bigger dob for my home area use. I just cant justify 15K for a large Dob. but I can justify 2500 for a blank and some plywood to get a close substitute.

[mapstar]

I was thinking about making the travel dob as my first to see how it goes then decide if I want to go for a bigger dob for my home area use. I just cant justify 15K for a large Dob. but I can justify 2500 for a blank and some plywood to get a close substitute.

Sensible thinking and building the travel dob would give you an idea of the cost of something bigger.

Even as a self build I would imagine through experience that £2.5k would be an extremely difficult budget to stay within to get a big scope.

Damian

[Scooot]

I put some measurements on my Sumerian review if it helps. http://stargazerslounge.com/topic/234459-sumerian-canopus-16-review/

The exchange rate is very good at the moment, I worked out recently it would be about £400 cheaper now

[cassiewoofer]

Have you looked at the OBSESSION TELESCOPES UCT telescopes.. they look great!