I have decided to begin an new project and after a couple of months without the ability to get out into the workshop, I have decided to build a 12" truss Dobsonian - basically a scaled-down version of the "big ones". Some of you ATMers may remember my initial 18" Dobsonian project
here, which I unfortunately had to end prematurely for family and health reasons. I hope
this thread will last longer than two pages! This scope will be a low maintenance, basic Dobsonian - no bells and whistles - so family and others can use it. More importantly, this scope will not be "over engineered" which can be an asset to a person's ability or a hinderence, depending on who you are. If this is successful, I may venture onto a larger Dob in the future.
On with the show...
Flotation Mirror Cell Design.
The first step was to design the mirror cell and despite my previous comment
"This scope will be a low maintenance, basic Dobsonian" I did decide on an 18-point flotation cell. I spent a few hours last night calculating the dimensions and drawing up the results on AutoCAD.
In most part, I rescaled the dimensions from
Kriege's book and confirmed them with some software and internet resources. The tolerances of the balance and pivot points, and the size of the triangles and bars are within a millimetre or two. For me, quite acceptable. Oh, and all my dimensions are in inches, don't ask me why, I just like imperial measurements! Here are the results: