Subjects
 
Optical Shop
Polishing Bowl
Edging Machine
Null Tester
Tube Fittings
Worm Drives
Optical Workshop Equipment
Spindle Nose & Adaptors
Slip Ring Seting Circle
Mirror Cell
Diagonals
Odds and Ends
 













 

DIAGONAL SUPPORT (Spider).

This is the design of diagonal support I have always used, using three hacksaw blades. It is incorporated into the top end ring of the tube. Carbon steel hacksaw blades are needed as they can be drilled. It was pointed out to me that the diagonal mirror was too close to the end of the tube and would dew up and be affected by stray light. Dewing is not a problem in Cairns. Anyhow I made the tube longer and changed the spider fixing. This is illustrated in the second drawing. Another modification was made, instead of the brass sleeve to hold the diagonal mirror in place. The dimensions on the drawing are for the tubes and focussing units I was using.

Though this eliminates the spikes on star images, an observer has told me that six small spikes are evident on the outer field on high magnifications.