[MHml] mast woes

[Paul Nudd]

Bill Gibbs wrote:
> I'm sure your points are also correct.  My rod and mast require proportionally more tensioning than a Tornado.  We are not looking
> for prebend however, as much as avoiding slack diamonds on the unloaded side.
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On XL2 we have swept back diamonds and a 'jumper' diamond facing 
forward. We set up with a foot of prebend, held in by the swept back 
diamonds, then we just take up the slack on the jumper. The jumper 
prevents the mast from bending much further than the foot of prebend (it 
will bend a little more as the jumper wire stretches). The prebend is 
there to make sure that the mast can never invert, even when the diamond 
wires stretch a bit. I am told that this is a safer solution than 
starting with a straight mast which will be vulnerable whenever there is 
any stretch in any of the diamond wires.
Perhaps this is also the case with Bill's rig, that inversion is the 
case to be avoided rather than just a slack diamond.
I thinkthe prebend in the tornado rign is for sail shape but I may be 
mistaken.
PN