by Roger Herzler

10/28/1998 (updated 8/5/1999)

Have you been giving thought to build your own telescope? If you're reading this you probably are. This is probably the most common question I get from web site email. Let me just say that I am into polishing my 10" mirror blank, the end is in sight (and has been for 5 months), and I can't be more proud. Of course, I've got a long way to go. I need to do the mounting system (truss tube Dobsonian); finish figuring the mirror, and send that off to be aluminized. I've got plenty of frustration ahead of me, but without a doubt, this is so far the best hobby experience I've ever done.

Is it for everyone? Absolutely not! Especially if you make your own optics. Grinding mirrors requires a lot of time. I attend an ATM (Amateur Telescope Making) group usually every Saturday, and there are plenty of folks in there that are still in fine grinding and been that way for months. However, with some determination and discipline (often there are a lot of other things in life to do besides push glass) it can be done. I started this project in April 1998 with the goal of being complete in one year. Even with a 3 months hiatus due to the birth of my beautiful daughter, I still might make that self-imposed deadline. I spend between 1-4 hours a week on the grinding. Would I recommend it to others? I do frequently, with some disclaimers first:

• Do you have the time to invest in it? This is the biggest part of the decision process, especially if you grind your own optics. I've spent a long time on my mirror because of errors that I made and wanted to correct. I could have stopped some time ago, but I'm trying to clear out some rookie mistakes that I made in the hunt for a great mirror. If you buy your mirror then this is not an issue and only the woodworking, etc. will take time. The time to make the mounting doesn't compare to the time to grind the optics, in my opinion.
• Do you have the money? $395 is a good estimate for a descent scope 6-8" Dobsonian. In my case I will spend well beyond that because I am only using high-quality parts. My project will run around $600 in the end, but much of that expense can be spread across more telescopes if I choose to build more (testing equipment, books, tools, etc.)
• Are you inclined to build your own stuff? If you're a handy person, or want to be (I fit in that group) then this will be a great hobby for you. If not, and projects around your house tend to wither on the vine, then you'd be better off buying a ready-made scope. Many times people start and can't finish it. We've got people in our class that have glass blanks from the 60's, indicating that they stalled out a long time ago, but they're back to get it on track.

A little more expansion on the question of whether it is expensive, or at least will you save money. Expense is entirely relative. So rather than say that its expensive, it is better to say that you will not likely save much money over purchasing a telescope. However, the quality you can achieve from purchasing higher quality components and (if you grind your own mirror) making your own optics are beyond compare. You can probably design a better scope cheaper than you will buy one of the same quality, but with the exception of maybe an Obsession or Astrosystem telescope, over-the-counter scopes are of lesser quality than you will build. For example, a Meade or Celestron Dob would be a lot more than they charge now if their components were of the same quality you can drop into your project.

Do I recommend it? Highly...for the right person. If you have little or no time on your hands, and you would have to sqeeze in the time just to observe with, let alone build a scope, save the time and buy one (a lot of time can be saved by buying the optics - without a doubt the biggest time hog is making the mirror). If you have the time to put into a scope, do it. So far the experience has been very rewarding to me.

Visit my ATM pages for more detail on good resources, links, books, etc., and stop by our Saturday meetings if you're in the San Diego area.

Good luck and keep in touch. Let me know how your project is going!

Roger