Starting the thing…

This project will consist of a 22" f/2.8 meniscus mirror made out of BVC, and a telescope based around it. The 22" is to replace my 24" scope, which I sold in 2022. The blank weighs only 38 pounds, which is not the lightest but it’s better than the 60 pounds of the 24". It’s 1" thick with a 0.5" deep curve (sagitta) so it acts about as stiff as a 1.5" thick typical blank, which most people would consider fairly reasonable. I could’ve gone thinner but wanted to alleviate the risk seeing as it’s already going to be the largest and most difficult mirror I’ve ever done.

Starting the thing…

My “small” Dobsonian telescope. Constructed and modified between December 2019 and January 2022, with updates still ongoing, this instrument is designed to do everything: wide-field vistas, sharp planetary views, and deep views of galaxies and globular clusters. The primary mirror is 0.8" thick quartz and made by Nova Optical. The secondary is a 3.1" Antares unit, accurate to 1/20 wave. The whole telescope is just 45 pounds, and fits in my passenger seat if I need it to. It can be assembled in as little as five minutes. Before I moved to Tucson it also had an equatorial platform for motorized, hands-free tracking - something all my other scopes lack. With a 21mm Ethos eyepiece, I can get a 1.7-degree true field of view - 3.5 full Moons across! Currently working on the 30th revision to it, featuring a new mirror cell.

Starting the thing…

This was my first homemade telescope, and the only one with a homemade mirror.. I ground and polished the mirror myself in August 2017 when I was 14 years old. The mirror is very good, but none of the structures I threw it in were anything resembling decent - though it did win 1st place Junior award at Stellafane 2018. I had a lot of good views with it, but dismantled it after a year. This scope made it into Sky & Telescope in September 2018. The second incarnation of the structure made it into TIME, The Guardian, and National Geographic.

Builds

24-Inch f/3.5 Dobsonian Telescope

My largest telescope yet, with a primary mirror made by Nova Optical. I got the primary at a steep discount thanks to a small edge chip. Other than the 25" Obsession at WAS and the Van Vleck Observatory 24", my 24" was the largest telescope in Connecticut.
The original scope weighed about 200 pounds and was transported in my Toyota Sienna minivan with a pneumatic tire/wheelbarrow handle system and handicap ramps. Setup time was roughly 30 minutes. The eyepiece is almost always reachable with little more than a short step stool and is low enough to stand on the ground about 50% of the time.
The new version of the scope (yellow bearings) is around 140 pounds, an inch or two shorter, and sets up in about 15 minutes. It also features fans, infrared-reflective stain, composite materials, and a slightly better mirror cell.
The 24" was designed mainly for viewing galaxies, globular star clusters, and planetary nebulae. With a 2454mm focal length (a bit longer than a C9.25), it’s unable to get a field of view much bigger than 3/4 of a degree, and I’m boxed in at magnifications above 100x at essentially all times. Such are the compromises of all large scopes.
Unlike my previous builds, I designed, welded, and constructed the mirror cell on this instrument and had to learn a fair amount of metalworking to connect and tap/thread all of the steel and aluminum pieces. I also learned how to work with composite materials and join together multiple layers of plywood.
The scope was rebuilt in late 2021 for a lighter weight, but I never used it much after moving to Tucson, so it is now in a new home in California.