Suggestions for a Home-Built Telescope 37
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."
Make vs. Buy (Score:5, Insightful)
Re:Make vs. Buy (Score:3, Insightful)
Surely somebody is going to figure out a way to
Re:Make vs. Buy (Score:2)
You don't want to overclock a telescope. They have to be perfectly clocked to work. And actually, as two different
a few links (Score:3, Informative)
Although a few might be outdated.
Good luck.
Focuser (Score:2, Informative)
It really makes a difference, more than anything else.
http://www.scsastro.co.uk/it060013.htm
Re:Focuser (Score:3, Informative)
He started with the standard cardboard tube, but other than that tried to make it as light as possible for mobilility.
What he found was that ballance isn't so hard, just use large washers for counter weights, but the lightweight scope jiggles more that the heaver scope. Also the force to break the teflon bearings loose jars everything more when there is less mass to move.
Joe
Optics (Score:2)
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.
Re:Optics (Score:3, Informative)
Sincerely,
a guy who recently bought a telescope with a shaky mount
Re:Optics (Score:2)
Good advice. A decent sonotube and plywood Dob mount is ridiculously simple to put together, and, unless you've really screwed up, will be stable. I can't imagine how you'd screw it up, but I suppose it could happen.
I threw one together last year, an 8" f/6. I used 16mm film cans for the alt
Re:Optics (Score:1)
Mirror cooling is also important, as well as good baffle design (not to mention the consequences of making the tube the wrong length).
Another book (Score:1)
Re:Another book (Score:1)
413 Poinsettia Ave., San Mateo, CA 94403-2803
a few suggestions (Score:1)
Re:a few suggestions (Score:3, Informative)
Before this, when I was in high school, he would wake me up at 3 am to help him put the scope away. (now I'm 32)
Joe
Portability (Score:1)
The Amateur Sky Survey (Score:2, Informative)
remember the advice of Kent (Score:2)
And remember that revenge is a moral imperative.
Other options (Score:3, Informative)
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 [skyandtelescope.com] and get out under dark skies.. sorry, this requires getting out of the city.
4" Dob (Score:1)
It's cheaper than cyberage! (Score:3, Funny)
Move into an apartment complex with attractive tenants.
Frensel lenses (Score:1)
Re:Frensel lenses (Score:1)
Fresnel lenses are fine for solar furnaces and the like, but not useful in telescopes.
I made a scope from these plans (Score:5, Informative)
Good luck, and have fun!
Re:I made a scope from these plans (Score:1)
Our club had an ATM workshop in May and we tested the true focal length of a mirror and then used Newt [att.net] to plugin the values which calculated the proper distance the secondary mirror should be from the primary mirror. Values included, the size of the and the travel of the focuser, focal length of mirror and the size of the secondary to name a few. I was surprised by the fact that a mirror advertised as F/6 may not be and you have to test it wh
Telescope builders Maxim (Score:1)
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.
Spinning Mercury Mirror (Score:3, Interesting)
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?
Re:Spinning Mercury Mirror (Score:2, Informative)
The fast majority of homebuilt telescopes are built using glass, pyrex or zerodur (all glasses of various compositions) mirrors. All newtonian telescopes f/8 or slower can sometimes be made with spherical mirrors, everything faster than that requires a parabolic mirror.
Many amateurs polish their own mirror
Re:Spinning Mercury Mirror (Score:2)
The main reason they use aluminum is that glass is so heavy, it sags under its own weight.
I have heard of some telescopes using many small reflectors vice one large reflector. Most mode
Mel Bartel's system, and other designs (Score:2, Informative)
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
Mirror Grinding (Score:2, Informative)
Learn how to collimate! (Score:2)
Spherical Primary (Score:1)
Find a local group! (Score:1)
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.