Last revised: December 22, 2010
Maintained by: Bob Lombardi, W4ATM
Hard to to grasp that I've been doing this for 20 years, but over the 1990 Thanksgiving holiday break, I put together this list for a very selfish reason. I neeeded it!
For the first 16 1/2 years of its life, this list had its home on the Tallahassee Freenet. It seems the world has moved past the need for Freenets and they decided to close the service in 2007, which started the search for a domain name and webhosting service. I was surprised to see this domain name available and simply had to grab it. But I'm not a dot com - I'm not a business. I'm just a guy who likes to build and tweak on telescopes, and share everything I know with anyone who wants to know. This site is paid for by me, out of pocket, with no reimbursement from anyone listed here. That's right; if you supply parts an ATM will find useful, send me your contact info, and I'll advertise your service or company for free.
For the first time in several years, I'm going to return to having an email link from this website. We all know how bad the spam problem is today - they say 2/3 to 3/4 of the traffic on the net is spam, and you simply must have filters to survive. I'm bob at amateurtelescopemaker dot com but you must put ATM in the subject to help me find it in the spam! If it doesn't have ATM in the subject, it's going in the trash automatically. I look at the trash folder, but might miss it if it doesn't say ATM.
Saturday afternoon here in my shop, working my 16" f5 thin mirror through fine grinding.
Welcome to ATM's Resource List. My purpose is simple: despite the widespread availability of cheap components and good optics, it is commonly believed that getting the parts to build a telescope is harder than ever. By putting together a list of companies that supply the ATM, I hope to help make sure that Amateur Telescope Making does not die off as a hobby, but instead grows into the future. It may be true that big companies don't advertise mirror making kits in Popular Mechanics like they did in the past, but the mirror making supplies are still out there, and ATM-made mirrors are often the standard of comparison for the best optics.
I first started putting the list together over the long Thanksgiving holiday weekend in 1990, and posted it to Usenet sci.astro that weekend. The list really started for a completely selfish reason: I needed it! At that time, I was using the net connection at a former employer. I started out posting the list to Usenet every few months, but have not posted it to Usenet in years - it got too big! The Tallahassee Astronomical Society was the first host of the HTML version of the list. I would write the HTML and email it up on occasion. Eventually, I got a net connection that allowed me to find a home for the list on the Tallahassee Freenet. In the same 17 years, the list has grown from a short page to what you see now, and the Web has gone from an idea to the fastest-growing information source in history. I have gone from using a work connection, to using a "big name" online service, to a private Internet service provider to a FreeNet located in Leon County, Florida, home of the Florida State University. In 2007, the list moved to its current home at amateurtelescopemaker.com.
If you have any experience with any of the companies on the list, new addresses or phone numbers, or any other feedback, please email me to get your updates included. Good, as well as bad, experiences are always welcome.
This list has a strong North American, and especially US, bias. This is strictly due to my resources in finding companies to list. I include links to a UK and a (mainland) Europe list of suppliers.
As this list is at its best when seen by as many as possible, feel free to link to it on a WWW home page. If you want a copy for inclusion in a CD Rom collection, please contact me. Please do not modify the list. If any modifications are needed, contact me to ensure that everyone sees the latest corrections.
I must issue the standard disclaimer: I have nothing to do with any of these companies, other than being a satisfied customer of a few, and an ex-customer of some others.
or email email@example.com,
Francis Milsom, the list coordinator.
As a telescope maker, I often get asked the question, "should I build or buy my telescope?". My favorite answer is "Yes!"; here's what I mean. If you're new to amateur astronomy, count me as one of those who recommends getting a nice pair of binoculars 7x50 or 8x56 as your first instrument. Higher magnification (the first number) makes the binoculars harder to hand hold so I'd recommend you stay clear of the 10x50 binoculars that you'll find. Larger numbers in the second place mean the objective lens is bigger, which is what you want for astronomical use. In general, 35mm binoculars such as the common 7x35s are considered the smallest ones worth getting for astronomy. Avoid bird watchers sizes (usually 15 or 20 mm). Get good ones (it's hard to go wrong with binoculars made by the big optical companies) so that if you decide that going to faraway dark places and staying up all night isn't as much fun as it first seemed, you'll have a nice pair of binoculars that you can use for life. If you're committed to astronomy, buying a reasonable telescope can keep you occupied while you take on the long task of building one. Nothing can be more frustrating than missing a beautiful night (especially if they're as rare where you are as they are here) because the telescope isn't working, yet. You can find used Celestron and Meade 'scopes pretty much anywhere, and one of those might keep you going while you build that 17" Dob that you've been dreaming of.
If you're considering doing your own optics, get the Willmann-Bell catalog. It's a small newspaper filled with interesting books, and they sell mirror making supplies.
Get Richard Berry's book "Build Your Own Telescope". Check out the chapters on homebrew optics. If you can't find an experienced telescope maker to help you, start small. It will take you less time to grind and polish a 6" f7 or f8 mirror and then do your fantasy 12" (or 17, or whatever) than to start with the big one. Even if you finish your 6" scope and then never use it. If you have someone to turn to for help, an 8" f7 or 8 makes a good starter scope. If you're going to work on your own, get Texereau's book. Between the two of them you can figure out what is going on.
Use a template to judge your rough curve. Cardboard is ok, you'll learn where the uneven spots are in its shape.
As you progress through the grinding stages, spend more time with the tool on top. In the finest grades the tool is almost always on top. Say one wet with mirror on top to 10 with tool on top. This concentrates the work on the edge, where you need it most. The outermost edge contains most of your mirror's area, the innermost circle is covered by the diagonal. (source for this idea, TM#6)
I like mats for molding the pitch lap. John Dobson uses a thin wooden dowel pressed into the hot pitch. One of the most common flaws in a first mirror is inadequate polish, and either of these techniques will help you get a better lap. In addition, you should micro-facet your lap with fiberglass screen (I got mine at the local building supply house). It can save you an hour on even a 6 inch mirror.
The opthalmic polishing pads that have been mentioned in S&T; and other places polish extremely fast, so I would recommend them only for someone who has already polished out a mirror on pitch. On the other hand, I wouldn't dream of doing a mirror over 10" without them. Place the pads directly on a pitch lap, not on a bare tool, be sure to monitor the surface with frequent Ronchi tests (just as they polish fast, they can also turn an edge extremely fast) and then follow the pads with a half hour to an hour on pitch.
You should test your mirror more than one way. The Ronchi test, using a grating of 85-100 lines/inch, is excellent for checking the surface during polishing to ensure you're not turning down your edge. It's also bright enough to do in normal room light, unlike the Foucault test. The star test can be a very sensitive way to determine the overall figure of your mirror, but requires a tube and all of your other components to test with. It may be even more important than the Foucault test, but do the Foucault or similar test anyway; it's the most accessible way to get the overall correction in waves that you want.
If you plan to buy commercial optics, learn to test a mirror anyway. You can use the star test or a Foucault tester. University Optics sells a nice tester kit, if you don't want to make one. One of the advantages of grinding your own mirror is that you build a tester and learn to use it as part of the process. Of course, you also have control of when it's "good enough", and are not under the production pressures that a commercial mirror maker is. Commercial mirrors vary in quality quite a bit, and even the best companies will occasionally let one slip by. So make sure you test your mirror and make sure you understand the test. Don't expect an f4 Dobsonian mirror to be optical perfection; it is quite difficult to achieve diffraction limited performance from an f ratio this short. Of course if you're paying for diffraction limited, that's something else!
There you have it. Enough references to get the beginner started. If you find this list useful, or if you find it lacking, I'd appreciate feedback.
The world famous pink clubhouse at Stellafane quotes the beginning line of the 19th psalm "The heavens declare the Glory of God". But the whole psalm has a neater meaning: "The heavens declare the Glory of God; the skies proclaim the work of his hands. Day after day they pour forth speech; night after night they display knowledge." The night sky is there to give us knowledge, if we'd only observe.
Look at you! You've read this entire page!! If you're really bored, go to my home page.