My 14" f/5 ultra portable dobson telescope project

At last I decided to give the 14" f/5 optics I bought more than 10 years ago a real life: I'll be building an ultraportable dobsonian telescope.

I start with the following parts list which I already have acquired over the years:

  • Primary mirror: 14" f/5 with focal length of 70.2" (1783mm) (1 inch thickness, to be precise: 24mm at the edge)
  • Secondary mirror: 3" (75mm) minor axis
  • Secondary holder and 4-vane offset spider vanes (manufactured by Gary Wolanski)
  • Low profile 2" aluminium helical focuser (manufactured by Gary Wolanski)
  • Finderscope: 8x50 (TAL; heavy but excellent)
  • Plywood from my previous ATM attempt (classical dobson, but very heavy and bulky)

Design decisions

Mirror cell

The mirror cell for this 14" f/5 telescope has been computed with PLOP. From the simulations with PLOP I have decided to build an alternate 9 points cell that considerably outperforms the classical 9 points cell for my primary mirror. The design consists of 1 central point and 8 additional points spread evenly on a ring. I have written input files for PLOP for this particular cell design since there was none. The cell does not use 3 triangles, since 2 of them would be very flat, hence making an accurate positioning of the center of gravity very difficult (a 0.5mm tolerance on 20mm is 5 times worse than the same tolerance on 100mm). Instead I designed the cell to use one triange supporting the central point, and 4 hinges (3 identical ones plus one for joining 2 of the former).

Some relevant links:

quilt cover sets's picture

  Thanks for making the

 
Thanks for making the sincere try to provide an explanation for this. I feel very sturdy about it and wish to learn more. If it’s OK, as you attain extra intensive wisdom, can you include more posts similar to this one with more information? It would be extremely
 useful and helpful for me and my colleagues. 
Thanks for making the sincere try to provide an explanation for this. I feel very sturdy about it and wish to learn more. If it’s OK, as you attain extra intensive wisdom, can you include more posts similar to this one with more information? It would be extremely useful and helpful for me and my colleagues. 

quilt cover sets's picture

  Thanks for making the

 
Thanks for making the sincere try to provide an explanation for this. I feel very sturdy about it and wish to learn more. If it’s OK, as you attain extra intensive wisdom, can you include more posts similar to this one with more information? It would be extremely
 useful and helpful for me and my colleagues. 
Thanks for making the sincere try to provide an explanation for this. I feel very sturdy about it and wish to learn more. If it’s OK, as you attain extra intensive wisdom, can you include more posts similar to this one with more information? It would be extremely useful and helpful for me and my colleagues. 

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