Make a Reflection Telescope

fairydream81 · Post by **fairydream81** » Sun Oct 15, 2006 1:36 am

Has anyone made a reflection telescope? Please share your experience.
I and some friends in my club tried making one.
This is a handmade 4" (10 cm) reflector .I thing it's better than 60mm (700mm length) MEADE refractor.

Now I'm grinding a 15cm(~6in) mirror for a bigger one

a myfriend have just finished,but because of cloudy sky in VietNam (rain and rain) we can't see any star for testing.( seem very good when see something :tree...)

Post by **Airconvent** » Sun Oct 15, 2006 2:27 am

Nice effort! I don't even know how to collimate mirrors, let alone grind them!
good luck on your new 6-incher....do let us know once its done.

ariefm71 · Post by **ariefm71** » Sun Oct 15, 2006 2:31 am

Has anyone made a reflection telescope? Please share your experience.

I made a few:
http://www.singastro.org/viewtopic.php?t=1834 (with kayheem)
http://www.singastro.org/viewtopic.php?t=3352

I never grinded a mirror though, so you're more advanced!

vainqueur · Post by **vainqueur** » Thu Jan 11, 2007 12:15 pm

i have always wanted to DIY one... but dont know how and where to get the materials... care for a short introduction?

Robin Lee · Post by **Robin Lee** » Fri Jan 19, 2007 10:49 pm

Is grinding a mirror hard? I want to try it too. Where can we get the grinding tool? I need to make a dobsonian mount as well. Anyone knows it?

Post by **perseid** » Sat Jan 20, 2007 1:03 am

Here is my 2 cents.

Assemble a telescope from ready made optic is much easier and maybe cheaper too. While grinding your own mirror feels more satisfying, it is not really easy to do. Raw materials aren't readily available. Polishing and figuring a mirror blank into a good mirror requires lots of patience and guidance for first timer.

A 6" mirror can be done in about a month, while an 8" one will take you twice as long. Even if you have done your job perfectly, you still need to send your mirror for coating. Cost of coating itself will be more expensive than buying a finished mirror especially for small 6" or 8" mirror.

I can supply those interested with all the necessary optics and parts. You'll need to make the mount and assembly. Half the fun of doing everything yourself but still save you a lot of heartache.

BTW, my 14.5" mirror is still at the final stage of figuring. The last time I work on it was two years ago, before my test equipment broke down. Hopefully, I'll start to work on it soon once I am hit with "mirror making fever".

rlow · Post by **rlow** » Sat Jan 20, 2007 1:57 pm

I have tried mirror grinding and I can tell you it is a lot of hard work, and definitely not my cup of tea. And making an excellent mirror is very hard to achieve for beginners. I would rather buy a finished mirror and build the rest of the scope.

Robin Lee · Post by **Robin Lee** » Sat Jan 20, 2007 9:26 pm

I see.. it's really challenging. By the way, where can I get a 6" parabolic mirror? Do I need spherical mirror or parabolic mirror to make newtonian telescope? I need a secondary mirror as well. Perseid will be the source?

Post by **weixing** » Sun Jan 21, 2007 1:42 pm

Hi,

I see.. it's really challenging. By the way, where can I get a 6" parabolic mirror? Do I need spherical mirror or parabolic mirror to make newtonian telescope? I need a secondary mirror as well. Perseid will be the source?

If you are making a "fast" scope... may be below F8, you need a parabolic mirror. If you are making a "lower" scope... F8 or slower, spherical mirror is good enough. Anyway, I think perseid do sell a 6" F8 primary mirror and secondary mirror, but I'm not sure whether it is parabolic or spherical mirror.

Have a nice day.

Robin Lee · Post by **Robin Lee** » Sun Jan 21, 2007 8:58 pm

Thanks for your info.

If I am making a Newtonian, I would like it to be faster.