Telescope Reviews: Ron Ravneberg Memorial Scope Gallery

I once heard Penn State's Joe Paterno say that such accolades were like poison ... only dangerous if swallowed.

I've always felt that ATM efforts should be INclusive, rather than EXclusive. What I mean by that is that one should always point out to others how they can adopt ideas and techniques, rather than making it seem that one needs special skills and/or exotic tools to do interesting work.

Granted, I've been building telescopes for a long time, but I'm not one of those ATMs with a well-equipped shop or access to a lot of fancy power tools. (I do have a simple drill press and a cheap router table, but that's about it for tools you don't hold in your hands.

I try to start with good materials (e.g., Baltic or Finnish birch) and square corners. The former I get at a local Woodcraft store and the latter I usually achieve by begging or borrowing a little time on friends' table or band saws.

After that, it's mostly attention to detail. People sometimes think I'm some sort of master craftsman because of the fancy inlays, but you buy the stuff in strips, glue it into place and sand and finish it along with the rest of the wood.

I try to think of interesting ways to solve problems, rather than slavishly following what others have done, and I try to make each component as good as it can be (e.g., stainless steel screws running in threaded brass inserts rather than regular screws in zinc-plated T-nuts). As a result, the components in my scopes work as well after two decades as they did at first light.

I don't do a lot of math, computing moment arms, and all that when I build (other than placement of optical components). I simply build what I think will work and adjust it on the back end to make it right.

I'm sometimes a bit dismayed when I read posts online asking for the "right" way to do this or that, as if there were only one way to do it.

I'm a particular fan of Dave Kriege's and Richard Berry's book THE DOBSONIAN TELESCOPE, but not as a step-by-step guide for building a particular telescope. Rather, like Ingalls' AMATEUR TELESCOPE MAKING books, one should read the material and learn how telescopes are made, rather than how to make one. Once a person truly understands what a flotation cell does, why a diagonal should be offset, or why just any combination of plywood, Teflon and laminate won't work well, he/she is freed to come up with ways of solving telescope construction problems and having a great time building a scope that is different from those that went before, even if only in one or two details.

There are no "right" answers ... no rules other than those dictated by basic physics, which one can often intuit if the actual mechanics are unknown.

I'm a fan of people "rolling their own" when it comes to telescope making. Nothing is less interesting than the next Obsession-clone.

People often speak of Dave Kriege as some sort of genius telescope maker who should be emulated. Well, that's partially true, but it's not necessarily his telescopes that should be emulated ... it's Dave himself and the way he got to the first Obsession.

Back in the late 1980s he showed up at Astrofest in Illinois, examined in detail the telescopes that were there (including my own 17.5"), made mental notes, and then went home.

Did he show up the next year with copies of what he saw the year before? Nope. In the intervening months he thought about what a telescope really needed to be (and not be), did a lot of materials testing, tried some new design ideas, pulled it all together, and came up with something entirely new. In the process, he kicked the Dobsonian design into its third generation and set the trend for the next two or three decades. Not bad for a Wisconsin dentist.

So, go forth and find new ways to make these 400-year old instruments work better ... and have some fun in the process.

Sure, you can (and should) take ideas from others (we all do), but don't just copy. Keep Albert Ingalls' comment in mind.

"It is not ... unsportsmanlike to study closely the details of telescopes made by others and to 'lift' this or that feature from them, provided one improves these features."

Peace, and Happy New Year.

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Ron Ravneberg