I did some digging on the subject of torsion bars (which the wing stays effectively are). The spring rate is proportional to the 4th power of the radius (minus the 4th power of the inner radius for hollow bars) It might explain why Marlin went from a small radius solid bar to the larger radius hollow tube. It would certainly reduce the bouncing (caused by the wing stay twisting). Its a pity they didn't get it right - I think it would have been a much better solution.
Some calcs:
Solid bar 10mm. Stiffness = 10,000 (somethings)
Hollow bar 16mm wall 2mm?. Stiffness = 27120 (somethings)
The hollow tube is 3 times stiffer.....
I still have the (unused) hollow wing stays. Perhaps a hybrid would be a good solution?
Stuart - do you intend to make some more of your clamps? I would be interested in a cost....
Robin
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