OK. So I finally took time to tune my mast according to Matt's instructions after they were de-tuned for the Alter Cup. After setting everything up the last statement in the instructions is that in the end I want to achive 1
to 3/4
of prebend. Is this measured by running a string from the very end of the mast to the base or from the diamond hounds to the base? Forgive me if this has been covered already. Thanks. Ed
I think its from mast tip.
Yikes! I thought it was the perpendicular distance from a line formed between the spreader tips to the mast at a predetermined diamond tension.
Kris
No, that is the spreader rake measurement.
For the prebend, tie a line to the mast tip and run it under the mainsail hook. Then tie the loose end off to the gooseneck, again running the line underneath it. Now lay the mast flat on it sides (or screw up your measurement) and measure the mast prebent by measuring the distance between the line and the back of the mast track IN THE HORINZONTAL plane ONLY. Most likely the mast will bend downwards and the tensioned line will be a little higher then the mast sail track.
Wouter
Wouter Thanks. Laying it horizontal does make sense doesn't it. Watch out guys, I'm tuning up!! As if that will make up for sloppy mark roundings. Ed