Restoring the OTA

Then as 'life happened', the telescope was left in the dust for about 30 years. Yes, I know... a serious crime! It was, however, carefully transported from 1 basement to the next. until I was finally in one residence long enough to consider re-entering the amateur astronomy world. Obviously a lot had changed! I decided to hold on to what I had as the instrument was basically intact and I didn't think I was going to do any better in terms of the optical quality of contemporary reflectors of similar aperture.

The original 10" f/7 primary was still in good shape except for the coating which was dirty, stained, and dulled. The OTA was a unique design for newtonians in that the basic tube was supported by an external ringed cage which allowed the tube to rotate inside of it such that the eyepiece could be accessed in any position. The fiberglass tube has aluminum rings which 'cap' both ends. These can be seen to the right leaning against the right side of the cardboard box.

The primary cell was in excellent shape and all that was needed there were some new collimating screws.

Both the primary and secondary were recoated by Spectrum Coatings, who did a great job! The brand new surface is seen here reflecting part of one of the observatory walls!

The OTA fiberglass surface was cleaned. Metal components were derusted and repainted. The inside of the tube (not shown) was also repainted a flat black paint. The secondary spider was in excellent condition and only minor touching up was required there. The ring cage was reassembled using teflon dowels which sit inside holes in the outer rings and engage the grooves of the OTA surface rings shown on the left. The dowels are held in posiiton by screws which were originally metal and had rusted. These were replaced with nylon screws one of which is seen in the center of the top ring on the right. The individual dowels were cut from bulk rods of around 6 feet in length which is how they are produced (see below) , and 5/8" width. Each dowel is around 3/4" in length. The 2 bolts protruding from the rings on the right are used to anchor the OTA to the mount cradle which is shown on the mount page

A piece of the bulk teflon rod which was then cut into smaller pieces used as the dowels is seen above. One of the old dowels is seen to the left of the screw.

The ring cage is nearly refinished here. The holes can be seen for the teflon dowels in each ring

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