Monday, October 2, 2023


I mentioned a few days ago my hope to make handles for the new rotating rings from Parallax Instruments for the 8" reflector.  

The 5" refractor rings (which do not rotate) have similar 1/4"-20 threaded holes.  Wildly enough I did not need an adapter plate to interface the handles to those holes.  There is about .01" difference in distance between the handle screw holes and the holes in the rings.  That is close enough that by turning in one screw a short distance then the other one, they lock down very solidly.  This refractor is light enough for me to carry just by itself but with the handles, I believe that I can remove and reinstall it by myself.

I had used the holes on the front ring to make a camera carrier but never used it for that purpose.

In retrospect, the black finish version might have gone better with the rings.  What was described as silver finish is closer to gray.

i have confidence in these rings.  Depending on who you believe a 1/4"-20 stainless steel bolt (made in Taiwan) has a shear strength between 1100 (a table I found by Google) and 3750 pounds (60,000 ksi x area (.25" x .25").  The tensile strength is less but nothing should even begin to overwhelm even one of the four bolts.

The handles bolted right on the rotating rings as well.

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