I’ve been thinking about building a folding refractor for years. I had even purchased a 5” m.a. diagonal at RTMC a few years back with this in mind. After seeing it on AM several times, I finally bit on veteral ATM’r Keith Lawson’s offer to sell/trade that 8.5” f/12 doublet you’ve been seeing in the forums. We met last Saturday at Patrick Bailey’s observatory in Tehachapi, and I traded my old C11 and a rehabilitated old Schaeffer mount for the lens an a few odds and ends.
Driving back home to Bakersfield, my mind was spinning with ideas. As soon as I got home, I decided to inventory the stock of old pieces of Sonotube laying on the rafters above my shop. Then I saw it!! Powder blue, 4 feet long, aluminum … it was the mechanicals from Jim Hodger’s 10” Newt. Jim had given it to me at RTMC last year after selling the optics but finding no takers for the tube and rings. Inspiration struck like lightning. It included cast aluminum end rings with cast-in three-vane spider and lugs for a mirror cell.
After not much thought, I hacksawed out the spider, cut and drilled a piece of ¼” aluminum plate, drilled and tapped the front end ring, and cut an off-center hole to take the adapter flange that Keith had turned for mounting the cell on the lens. I had it put together by dinnertime.
During the last few days, I’ve mounted the rings on a dovetail for my mount, added a top plate, and mounted a plate on the back end for the first flat and the focuser. I have also built a bulkhead that will take a second (3.1”) flat to complete a z-fold light path.
With three weekends left before RTMC, will it be finished in time? It’s come down to the last few do-overs on my 12.5” cassegrain with suspect optics, or slapping together the refractor. Refractor wins.
In the pics you can see the offset of the flange for the objective. Obviously I’ll need to patch Jim’s focuser hole and thoroughly rehab the tube. The blue has to go – clashes with the gloss copper metallic powder coat for the mount.
Driving back home to Bakersfield, my mind was spinning with ideas. As soon as I got home, I decided to inventory the stock of old pieces of Sonotube laying on the rafters above my shop. Then I saw it!! Powder blue, 4 feet long, aluminum … it was the mechanicals from Jim Hodger’s 10” Newt. Jim had given it to me at RTMC last year after selling the optics but finding no takers for the tube and rings. Inspiration struck like lightning. It included cast aluminum end rings with cast-in three-vane spider and lugs for a mirror cell.
After not much thought, I hacksawed out the spider, cut and drilled a piece of ¼” aluminum plate, drilled and tapped the front end ring, and cut an off-center hole to take the adapter flange that Keith had turned for mounting the cell on the lens. I had it put together by dinnertime.
During the last few days, I’ve mounted the rings on a dovetail for my mount, added a top plate, and mounted a plate on the back end for the first flat and the focuser. I have also built a bulkhead that will take a second (3.1”) flat to complete a z-fold light path.
With three weekends left before RTMC, will it be finished in time? It’s come down to the last few do-overs on my 12.5” cassegrain with suspect optics, or slapping together the refractor. Refractor wins.
In the pics you can see the offset of the flange for the objective. Obviously I’ll need to patch Jim’s focuser hole and thoroughly rehab the tube. The blue has to go – clashes with the gloss copper metallic powder coat for the mount.
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