Mark's Notes for the Amateur Telescope Maker

"Surely the making and putting into use of a powerful astronomical telescope goes far toward properly orienting one's self in the great scheme of things."

—— Russell Porter

Latest News: I've been trying to scan in some of the hard to find articles that might be of interest to other telescope makers, and to make them available. The first of these is the Bulletin A published by Sky & Telescope. This Bulletin used to be available from Sky Publishing, but as far as I know they don't actually have this in print anymore. It's being distributed in the DJVU format, which is a highly compressed but high quality format for scans. You can download a viewer for Windows from Lizard Tech.
News: I've recently moved this website from my poor aging 133Mhz Pentium 5 (damn fine little machine, very reliable) to my poor aging dual 400Mhz Celeron box. Since the machine is faster, I can do a bit more with it. Toward this end, I've registered the domain brainwagon.org, and started a weblog that concentrates mostly on science, but will stray into whatever areas I think are interesting, including astronomy, building scientific instruments and telescope making. I'm also pondering the creation of a telescopemaking weblog. Stay tuned for more information.

Introduction

By way of introduction, just let me say that I love telescope making.

I've been helping to teach telescope making at the Chabot Telescope Maker's Workshop for the past nine years. In that time, I've often thought that it would be good to have a comprehensive set of notes that details most of the practical details that someone needs to know to build a telescope. What you see here is a very modest beginning, but like everything else, you never get anywhere if you don't begin. If there are topics that you would like to have covered, then please write me a quick email telling me what you would like, and I'll try to write something up or point you to other sources on the World Wide Web where your questions can be answered.

The Master List of Mark's Notes for Beginners

Telescope basics: What are the different types of telescopes? How does a reflecting telescope work? Why do most amateurs make reflecting telescopes instead of refracting telescopes?
Magnification and Aperature: Why is magnification not necessarily the most important feature of a telescope? What can I expect to see with a small telescope?
That sounds too hard, what advice can you give me about buying a telescope?: How much money should I spend? Are inexpensive department store telescopes worth the money?
Telescope making books: What books can you recommend for the beginning (and more advanced) telescope maker?
Getting started..: How much will it cost to make a telescope? What materials do I need? How long will it take? How old do you need to be to make a telescope?
Mirror grinding: How do I make a tool? What abrasives do you use for grinding? How do I start grinding? How long should I go for each grit? How can I be sure it is safe to go on? How can I avoid scratching?
Mirror polishing: How is polishing different than grinding? Why do I need to make a pitch lap? What kind polish do you use to make mirrors? How do you make a pitch lap? How do you press your mirror? What if I need to rechannel?
Mirror figuring and parabolization: What are common defects and how can I detect and correct them? How can I avoid a turned down edge?
Telescope testing: How do I test my mirror? When do I know that I am done?
The Ronchi Test: How can I build a Ronchi test? How can I map what I see to what problems there are on my mirror?
Assembling a telescope: Now the the mirror is done, what else do I need to do to assemble a telescope? What parts do I need to buy? What parts can I make myself? How do I build a Dobsonian mount?
What software can help me design and test my telescope?: Here are some links to software that you might find useful to design and test your own telescopes.
Where do I go to learn more?: There is a thriving telescope making community available on the Internet. I'll try to keep up to date on whose got great information, and present the best links here.

Notes for the More Advanced Amateur

Many of these notes deal with more advanced topics in telescope making. Some are little more than jottings of things that have interested me.

The Kutter Schiefspiegler: The Kutter Schiefspiegler is the simplest of the tilted component telescopes. It makes an excellent small planetary scope, and is fairly straightforward to construct.
The Yolo Telescope: Art Leonard invented the Yolo telescope, another example of a tilted component telescope which uses two concave mirrors and is unobstructed. To cancel out astigmatism requires either a warping harness or careful polishing to introduce a toroidal figure on one or both of the mirrors.
Tom Waineos' Grinding Machine: An excellent design for a simple grinding machine that can be constructed by amateurs.

Miscellaneous Notes

This is mainly a list of things that don't necessarily have to do with telescope making, but that other people might find interesting. I mean as much as one might try to do telescope making all the time, sometimes other interests do intrude...

Astronomical Images from Australia: Back in 1987 my friend Jeff and I went to Australia and did a bit of hiking, camping, observing and astrophotography.
Animation of the Nov. 15, 1999 Transit of Mercury: My first foray into the world of video astronomy.
Lunar Eclipse, Jan 20, 2000: I wasn't really prepared for this one, but thought I might shoot some video just using the zoom function on my camcorder.
Restoration of a 20" Refractor: Recently Chabot Observatory was moved to a new multimillion dollar site. As part of the move, a group of amateurs decided to refurbish the 20" Brashear refractor (known affectionately as Rachel) prior to installing it in the new dome. Thousands of man hours later, she looks beautiful. I took part in helping out, these are mostly some of the pictures that I took.

Mark T. VandeWettering <markv@telescopemaking.org>