Bob’s Dob

In 2000 the Thunder Bay Centre of the RASC got an opportunity to rebuild a 17.5” Newtonian telescope. It all started around the end of September when one of our founding members, Beverly Bishop, asked Doug Stuart to get a group of members together to have a look at her late husband Bob’s homemade Dobsonian telescope. It had been already looked at a few years back by Stargazer Steve, Ted Bronson and John Bakkelund. At this point it was decided that the scope was out of balance.

Original Configuration

Most of us involved wanted another look at the scope to see what may be required. Quite a few e-mails flew around among the members and on October 5th many of us got together at Beverly’s house to have a look at it and see what was needed to fix it up.

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One thing led to another and soon we were disassembling the scope. The main mirror, mirror cell and focuser were removed. We examined the main box, the truss assembly and the top cage. We found that the main mirror was quite dirty and the pinion on the focuser was bent.

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The truss assembly was a little loose and the cage design seemed to cause a culminating problem because it rotated within the cage. We talked about doing a quick fix to get it running quickly.

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Members at the session included Doug Stuart, Ted Bronson, Allan Huard, Ed “Webmaster” Kucbel, John Bakkelund, Bruce Miron and Beverly Bishop. Afterwards Doug agreed to clean the mirror and Ed was to repair the focuser, which they have done. We also decided that it needed a new mirror cell. Many more e-mails, a lot of ideas and one more meeting later we came to the conclusion that our best option was to rebuild the scope entirely. A typical Dobsonian construction was decided upon. Although not as portable as we would have liked, this was the simplest approach.

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We are now at the point of ordering our main parts, new mirror cell and a Sonotube®. Now it’s time to start rebuilding the scope. It will pose many challenges, but I am sure with this group we will overcome them and end up with a wonderful scope for all to enjoy.