Telescope Construction!

[Ola D.]

Hey guys,
I need a simple help.. Since u have this wide experience of using telescopes and all these stuff, i have this Q: how are telescopes constructed? I mean from what and in which design and way? I know it's basiclly made up of lenses or mirrors ( Reflectors and Refractors ) But i need a detailed design of a basic telescope.. It's only that am trying to build up my own telescope :)

P.S. I would be really grateful if u can provide me some useful links and sites! Give me everything you have :D Thanx for the help!

[Dave Mitsky]

You may find the many links at http://www.efn.org/~mbartels/tm/atm.html useful, John Dobson's site - http://tie.jpl.nasa.gov/tie/dobson/index.html - for example. In addition, there are a number of books on amateur telescope making.

Dave Mitsky

[Ola D.]

Thanx alot! It's great.. Really helpful :)
Well if u have any names of books in mind, please post them..
Besides, i was just checking Astronomy books on-line , but there were many which made me confused! So which book/books do u highly recommend?

[seeker372011]

I believe a classic is Richard Berry's "Make your own telescope"

http://www.wvi.com/~rberry/mybooks/mybooks.htm

[imported_astro]

:D Hey:

Tell me, what size of scope are you thinking of building?

Do you already own a telescope?

It's a fun project if you decide to build it yourself, lots of pride when it's completed.

[Dave Mitsky]

Another is _The Dobsonian Telescope_ by David Kriege and Richard Berry (see http://www.globaldialog.com/~obsessiontscp/Book.html for further details). David Kriege is the man behind Obsession Telescopes - http://www.globaldialog.com/~obsessiontscp/OBHP.html

Dave Mitsky

[Ola D.]

Thanx Dave for your help.. i've decided to build up an 8" inch Dobsonian telescope... the one u gave me the site for. Thanx again :)

Hey astro, Actually i have no telescope yet. The thing is that we have no main telescope shops here in Jordan, unfortunately :( i'm thinking of ordering one online. Does it work anyway? my friend is going to UK too, so maybe it'll be a lucky chance for me <_< Since i have very little experience with telescopes, i went to the Astronomical Society for help, a guy told me that's good but it would be difficult when it comes to mirrors and how to find the perfect focal length, maybe even sculpturing one.. I donno actually

Ya sure.. it's gonna be a very fun project :D

[Donald]

Sculpture a mirror? I never heard it said that way. What you do is to get a mirror kit which includes two Pyrex® blanks. The one with the least number of tiny bubbles near the surface becomes the mirror; the other becomes the tool. Also included in the kit are a variety of abrasives, pitch which is used to make the surface on the tool used in polishing and figuring and the polishing compound.

Figuring uses a variety of polishing strokes used to take the spherical surface left on the mirror at the end of polishing to the paraboloid, which brings all the light rays to the same focus, depending on the quality of the testing device. Purchased (or made) separately, the Foucault testing device that most use is made with a micrometer that can measure to a thousandth-of-an-inch. The best you can make a mirror with that device is one good to 1/20-wave P.V.

I used a tester with a micrometer good to half-a-thousandth of an inch. My surface is good to 1/38-wave P.V. My secondary is a fused-quartz flat good to 1/20-wave P.V. so my system accuracy is close to 3/20-wave P.V. I finished the mirror in time for the transit of Mercury across the face of our sun in 1952. The mirrors were not yet aluminized and I used a set of five Neutral Density filters. Now I use Enhanced Aluminum, overcoated with Titanium Dioxide on my mirrors.

I designed the mount for my 10"f4 and a friend who worked in a machine shop made it for me. It is an equatorial fork. I don't, BTW, like the Foucault tester described in Barry's book. The least expensive way to get the test equipment is to join -- or found (which I've done) -- a mirror-making group. The group buys the test equipment and provides a place for this interesting hobby.

May your skies be clear and your surfaces accurate,

Donald

[Lomitus]

Hey Ola,
Just a thought for you to consider here...there are a number of telescope suppliers avialable online, including Orion (www.telescope.com) and Hardin Optical (www.hardinoptical.com) who have some pretty decent scopes at reasonable prices. Yes building your own scope if fun and you can take a lot of pride (and chances are your gonna have a better scope for it if you do it right), but if your just getting into scopes, it can also cost nearly as much to build one as to buy one. Unless your planning on "pushing your own glass"...and even that can be costly for just one mirror and it's quite difficult from what I understand if you don't have someone experienced to show you how (i.e. you could screw up a mirror blank or two before you get it right and blanks can be pretty pricey)...a really decent mirror for an 8" scope can get into a couple of hundred dollars or more and the price jumps drastically with each inch of aperature. Ya might want to at least take a look around online before you start building and compair prices.

I had considered building my own for a while since there aren't really any dealers in my area either...until I started pricing the parts. When I weighed that against the labour involved, along with my own inexperience, it just seemed better for me to buy a scope (I got an Orion 127mm Mak that I really love). Just an opinion here, but it seems to me that building scopes is really more for the hard core folks that have been into astronomy for at least a few years, but it doesn't really seem practical or economical for someone who's just getting started...again, just an opinion though.

Not tryin to discourage you or anything...I think the idea of building ones own scope is really great...just trying to provide an alternative for ya :).

Either way, I hope it works out for ya!
Bright Blessings,
Jim