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Suggestions for a Home-Built Telescope
hodet asks: "I would like to know if anyone here has built or are planning to build their own telescope. My plan right now is to build an 8" F/6 Dobsonion Reflector based on these plans. The same design can also be found here. The base has been cut and the primary and secondary mirrors are to be ordered shortly. Since I plan on making a few modifications to this design I'd like to know if anyone here has done anything similar or totally original and what thoughts and suggestions you may have. I know it may be cheaper and easier to buy one from Meade, but that's not what I'm looking for."
I've made a 6" reflector, and I've bought one. You don't make a telescope to have a telescope, you make it to make it. It's the process that's important. The fact that you end up with a telescope is almost secondary. It's sort of a spiritual thing, when you spend hours and hours grinding, and consider those who've done the same over the centuries.
"I may be synthetic, but I'm not stupid." -- Bishop 341-B
can be found at dumbo
Although a few might be outdated.
Good luck.
Instead of making a focuser, you might be happy buying a really nice one instead. Out of everything you put on the scope, the focuser and the mount will be either a source of pleasure, or a source of annoyance. A good focuser will make it much easier to get the best views of the stars, and proper balance and stability of the mount will make it easier to point the scope.
It really makes a difference, more than anything else.
http://www.scsastro.co.uk/it060013.htm
This is America, damnit. Speak Spanish!
My recommendation:
Spend as much as you possibly can on your lens or mirror, and as little as you can on everything else. The rest of the materials dont matter much, but if you optics aren't up to scratch, the whole thing is useless.
"When I grow up, I want to be a weirdo"
My brother, Norm, wrote a book with Dobson, which is unfortunately out of print now. I copied the following from the net. It should be useful if you can find it: "How and Why to Make a User-Friendly Sidewalk Telescope" by John Dobson with Norm Sperling 169 pages; 154 clear,friendly line drawings; 9 photos. Hardbound in plywood (Dobson's favorite material) Exclusive source. $39.95
I own a celestron 8" dob. The big thing you need to consider it potability. You aren't going to be leaving it out in the middle of your yard, so every time you want to use it you are going to have to move it around. Consider adding some locking caster wheels. Handles are another nice thing. Think about how it is going to fit in your car
There are some interesting photos and information on Tom Droege's TASS site. Not sure how active they are at the moment, but there are some knowledgeable people there.
"Always keep your optics clean."
And remember that revenge is a moral imperative.
This is the first time I've seen an article
where all the replies were 1 or better, so
here's a big fat 0 for you!!!!
Build the scope yourself, don't spend all that much money on the focuser (better yet make your own focuser) and spend the saved dough on additional eyepieces. You can get a "better" focuser later.
A 6-inch f/8 scope is a wonderful starter - much better then the junk you find in stores. Hundreds of deep sky objects, craters on the moon, moons of Jupiter and rings are Saturn are all easy to see.
Final advise. Locate and join your local astronomy club, go to a regional star party (can you find both here and get out under dark skies.. sorry, this requires getting out of the city.
I've made a 4" f/8 Dob. The mirrors and focuser where from Orion. The tub is a 5" PCB pipe, the base is made out of wood. Before I made this, I bought a 8" Dob from Orion(the XT8). It was fun making the 4" but it can't compare to the quality of the 8" I bought. The 4" is a WAAAY better than telescopes you'll find in department stores, however it was the little things that make it not as nice to use as the 8". I needed counter weights and I have a little problem with friction with my mount. I've had to make use of Teflon tape and alumminum to make it smoth out.
Enjoy making this one hope it works out great!
"Suggestions for a Home-Built Telescope"
Move into an apartment complex with attractive tenants.
"Derp de derp."
Consider frensel lenses. You can get a very large Frensel lense at a relatively cheap price. They cause eye-strain if you look through them for very long periods, but how long are you going to just sit there staring through the telescope?
social sciences can never use experience to verify their statemen
I saw one guy mount his Dob in a wagon, the same type of red wagon you may have had when you were a kid. Great for someone who observes mostly from their yard. Roll it out into the yard to observe and back into the garage when done.
Good luck, and have fun!
I do not remember it exactly, but ...
It is faster to build a 4" and then an 8" telescope than it is to build an 8" telescope.
I use this frequently when I am trying to convince someone to build prototypes before doing a full fledged system.
If you want a large but immobile telescope, there's a way to do it with a large spinning pool of Mercury. Some canadian university built a nice observatory doing this.
The limitations are that they have to wear breathing protection around it due to Mercury outgassing vapor and them (understandably) wanting to avoid heavy metal poisoning.
However, it apparently makes a wonderful mirror, albeit a parabolic one. It would be interesting if someone could set up a manufacturing process whereby we would spin up Aluminum as a mirror base then spray a thin layer of Silver or chromium onto it to give a polished surface.
Of course I don't know jack about mirrors except that grinding glass ones is a pain in the butt and therefore costly.
Anyone know more?
Unitarian Church: Freethinkers Congregate!
Depending on your fabrication skills and facilities, you might also want to look into a truss dobson (probably not necessary at 8"), or a split ring mount. The split ring mount is an equatorial mount, making it easy to add a motor to track objects against the earth's rotation. Even if you want to learn the sky for yourself (rather than use a goto system), tracking is very very useful, particularly when sharing the views with others. The split ring also avoids field-rotation at the eyepiece allowing long exposure astro-photography using film or digital cameras.
I started out with a 10" meade starfinder dob, rebuilt it as a truss scope (goto), then rebuilt it as a split ring (motorized but not goto). The Meade starfinder design is very similar to the one you referenced, and is by far the easiest to build.
Be aware that astronomy is a disease, I don't know anyone who uses a telescope regularly and only owns a single telescope.
Dean
I know you're planning to buy your primary mirror, but you might like to read Ed Grinds a Mirror from Ed Ting's excellent astronomy site. Also, if you ever need advice on production scopes and accessories (like eyepieces), Ed's site is the place to go.
The most useful thing anyone who owns a telescope should know is how to perform and analyze a star test. A very thorough treatment can be found in this book.
By the way, the Willmann-Bell web site has a number of outstanding amateur astronomer books at very good prices.
I think you will find that it will be easier to grind a spherical primary mirror rather than a parabolic one. Look here for implementation instructions. there will neet to be a resulting adjustment to the secondary optics to compensate for the difference in shape. but the grinding process will be much simpler.
I've been looking into building a telescope, too and was wondering if anyone had a link to how to use a CCD to make the telescope digital - I'd like to hook it up to an old laptop, maybe even set up a wireless connection to transmit the images so I can set up the scope outside and observe from indoors.
I've not built a telescope, but I've got a friend who's made a bunch, who runs TelescopeMaking.org, and in talking with him it seems like the key to success is to find your local telescope making group and hang out with them on their work nights.
You'll have the experience of people who've already made several, be able to borrow some of their tools, and share parts and ideas.
Besides which, you'll probably meet some cool people.