The telescope you see in the pictures above is a close clone of a 12.5” Obsession. It is not for sale. I built it during the summer, fall, and winter of 2006-2007, using Dave Kriege’s book and measurements from a true 12.5” Obsession as guides. Hence the name Dolly K., borrowed from the name of the first cloned animal, Dolly the sheep! The name Dolly K. refers to the cloned nature and borrowed specifications of the Original Obsession.
There are some differences in the scope compared to the Original. I used almost entirely ˝” BB plywood for nearly all of the wood parts whereas the original uses mostly 5/8” plywood. This was an oversight on my part, but it seems not to have affected things adversely. Also, my rocker box sidewalls are nearly 1” thick instead of ľ”. I did this so that my accessories would be more stable and put less of a strain on the sidewalls, as well as provide a wider surface for the Teflon pads, a consideration for when I add a ServoCAT Junior at a later date.
Other differences include the UTA attachment cam clamps. I purchased them from Rockler. The fittings are made from aluminum angle very similar to those described in Dave’s book. I also positioned a “slaved” piece of 1” tubing to the left of the focuser so that I could attach a Telrad to it similar to the larger scopes which do not have the focuser off center. I put a piece of wood to the right of the focuser for holding a ServoCAT wireless handpad (someday).
The aluminum bearings are Obsession originals. The secondary spider and holder came from Astrosystems. I did not make the mirrors! The primary is from Discovery (I was on a budget and it cost less than a thousand). The secondary mirror is from Protostar. Nearly everything else is homemade. The mirror cell is a carbon copy of the Original, nearly. I did my very first welding while making it! The instructions in Dave’s book are fabulous on all accounts. The use of fixtures is especially important.
The wheelbarrow handles were made from a knot-less northern white cedar 2x4 found at Lowes, and 8” wheels located at Harbor Freight.
If imitation is truly the sincerest form of flattery, then Dave Kriege needs to know his telescopes have been duly flattered.
I have a 20” (true) Obsession, so why did I want another one? I decided I needed to go through the experience of building a complex telescope. OK, so a Dob is not so complex, but I have ways of making it so! I also felt I needed a smaller scope to use at public outreach events, take on non-star party trips, and to use in the neighborhood. In other words, I wanted something more portable. So, why didn’t I buy one instead of building one? Aside from the experience angle, I had the time and wanted to save some money. I did accomplish the latter, but it took a lot of time and energy to build it. On the other hand, I enjoyed the challenges I faced in solving particular issues. However, my advice is to buy the Original. You will get your telescope a lot sooner, especially if you do not have time on your hands! The Original is a great value.
- Charlie S.
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Copyright 2003-2007, by Charles Starks, Charlotte, NC, All Rights Reserved
Updated: 9:14 PM 1/6/2008