(Re)building my first telescope.

So I fully realize that I am starting the story of the telescope in the middle. Here is how I came to restart work on my  mirror. The little guy above playing with a metal lathe is my son. He's into everything, and  will probably get elected "Most likely to own a plasma torch" in Kindergarten.   We took him to his aunt's house where he found a toy telescope. He got very interested in stars and telescopes, which of course got me reading up on the subject again.  And, as mentioned  in my last post, I  happened to run into a friend who both had an interest in telescope making and  a polishing machine.

I first got really interested in astronomy when my parents gave me an Edmund Scientific 3" telescope for my birthday when I was in 2nd grade. I  loved  that thing and used it extensively, even when I had access to larger and better telescopes.

Unfortunately, through years of neglect and storage, it became practically unusable. The mirror needed to be re-silvered, the tube was cracked, and the mount was both too small for me and too frustrating for my son to even thing of using.  I decided it was time to convert it to a Dobsonian mount.

As you can see, the tube was in bad shape. that black band isn't a racing stripe, it's structural electrical tape. At some point I had dropped the telescope.  I chipped the mirror, but thankfully it was on the back of the mirror and didn't matter. Standing next to it is Schedule 80 PVC  pipe.  After months of looking around for a cheap cardboard tube to make into a new telescope tube, I found that. Usually it's sold in the garden section of you local home warehouse store. Its used in French drains, so it's usually perforated, but I managed to find a section that wasn't. For about $5, I got an 8 foot section, which was enough to make 3 tubes. I got it mostly right on the second try, so I have one section left over in the junk pile.

After cutting it to length, the first step was to sand it down. PVC doesn't take paint very well, so I had to  prime it, and to do that I had to get the glossy finish off.  After that, it was time to prime.

Fortunately I had a lot of paint laying around the house, because it took  a good bit. I think 2 cans of Krylon primer and 2 of paint.

The contraption in front of the tube is a flapwheel sander I adapted by attaching it to a  3' long threaded rod. I used this to sand out the inside of the tube.

Here is the tube after painting. I had almost the correct color of paint laying around from some materials test when I was thinking of builidng an electric guitar. I believe the color is called "Candy Gloss Red", but I prefer to call it "Caprica Red".

And finally, with the mounted hardware. The finder rings are slightly out of alignment, but it's a very subtle thing. Considering I'm probably going to replace the finder with a Daisy optical site pressed into service as a telrad-clone.  I even managed to salvage the Edmund Scientific logo sticker. Apparently the secret to adhesive removal is "wait 30 years and give it a try"


Of course, the scope is useless without a mount. That'll be my next post.