Serrurier Truss Designs

[Merlin66 (Ken)]

Can't help myself at times. The original Serrurier truss design was conceived by Marc Serrurier for the 200" Hale telescope back in the 1930's. I have a copy of his original CalTech paper.
His design is based on two balanced trusses providing equal end deflection without rotation, this means that the main mirror and secondary mirror trusses could be allowed to sag but hold the mirrors parallel to the optical axis without relative tilt.

None of the current Dobbie "truss" designs comply to this design! They normally only have one truss section and if they have two ( one on either side of the dec bearing) I do NOT believe they are designed and calculated to give equal deflection.

So, NO "Serrurier" truss descriptions for Dobbies....please.

[AstroJunk (Jonathan)]

Originally Posted by Merlin66

So, NO "Serrurier" truss descriptions for Dobbies....please.

Sorry mate, but since when did Dobson incorporate a truss of any description into a telescope?

I think you should rephrase that to "NO 'Serrurier' truss descriptions for large Alt-Az Newtonian telescopes"