Tuesday, January 14, 2014

First Light With The New Scope

I actually have a clear night tonight, and as you might expect in January at this latitude and altitude, it is cold.  I had to do one last thing before taking it for its evening dose of photons, and that was figure out a way to mount a finderscope on it.  It came with an attachment base that at first glance looks a bit odd, but is actually quite clever.  I just needed a way to create a finderscope base on which to mount the finderscope rings, and then a way to mount the base on on the mounting stalk platform.

The first picture shows the finderscope after I installed my semi-Frankenstein ring base:

The second focuses more on the mounting stalk, and I think might be a bit more useful for understanding what I made for mounting:

The nicely striped piece of wood clamps onto the 1" diameter aluminum tube using a 1/4"-20 carriage bolt.  (There is a slice cut out of the wood so that tightening the wingnut on the far side locks it down on the tube.)  I measured the thickness of the wood, and it was .870".  I took a piece of scrap acetal that I had lying around that already had a 1/4" hole centered in it, and machined a .875" wide slot about 3/8" deep across it.  This used a 3/4" roughing mill.  (I did not measure the depth, because it really did not matter.)  This made it a tight fit onto the wood.  The carriage bolt tightened down into the acetal, and made it quite rigid. 

The rings have 8-32 threaded holes .721" apart, so I used the vertical mill to make pilot holes at both ends of the acetal, then finished them with a .172" twist drill on the drill press.  I screwed everything together and voila!  It was ready to install.

By doing a little adjusting, I was able to get the finderscope lined up nicely with the optical axis of the scope.  Then it was just adjusting the fine screws.

This was less than a perfect night for first light, and not just because of the cold.  We have a full Moon, and it washes out just about everything, including Jupiter, which is only a few degrees away at the moment.  Still, the Swayze mirror is definitely better.  I could see detail, even on a full Moon, that I do not recall ever seeing before.  The image started to lose sharpness at 333x, but on a full Moon, with a mirror that had not had a chance to fully adjust to the cold, that's nothing startling or horrifying. 

Jupiter, of course, was seriously washed out -- but still better than the last time I used this telescope.  There were at least four dark bands visible, and a bit of other detail as well.