I built a new rocker box for Molly the 16 inch Dobsonian telescope today. She has been top heavy and required a counterweight (an elastic cord) since I built her about 20 months ago. The new rocker box is 4.5 inches taller which allowed me to raise the bearings up and shift the 24 pound mirror back by the same amount. Obviously I’m not done, there is stain and poly to do not to mention attaching laminate and the ground board but I think the problem is solved. The picture shows her tilted nearly horizontal with an eyepiece and everything with no kind of counterweight and she handles it just fine.
I won an Explore Scientific eyepiece – 3 mm in the 52 degree series – from Explore Scientific. It just arrived today in the snow (in mid-November?) I also recently purchased a used 32mm Plossl, no picture available, but that will give me three good ES eyepieces (3, 8.8, and 14mm) and one low power eyepiece.
Following up on my post about my new 11″ SCT Elf, I knew it was a little out of collimation. I’ve borrowed an artificial star from my friend Steve and had nebulous plans to use it. Saturday morning I realized that my office had a long hallway that would likely be long enough so this afternoon I gathered up everything I would need, including Samantha Dixon, and headed over there.
We placed Elf on a folding work bench at one end of the hallway and the artificial star on another 39 steps away at the other end. Approximately 115 feet of separation. The blurry thing at the bottom of the first picture is the artificial star and it is featured with all but one “star” covered up in the second picture.
It took a while to actually get the scope aimed directly at the artificial star but once it was, Sam and I were able to tweak the screws to center the black central spot in the rings. See the last two pictures. This was noticeably off center when we started. First we looked through an eyepiece then I switched to my planetary camera to make final adjustments. Looking at it now, maybe it still needs some work to be perfect but its pretty close. That said, the method works.