I discussed the issue with engineers... There are some variables I could imagine.
- Sailing loads will cause the mast to lean back and cause drum wear. Sheeting out and then furling should correct that one.
- Position changes in the drum location on the mast (production or slip during use).
- Wear of the pin inside the mast base.
- Flex at the cup to crossbar connection.
- Bearing plate position on the V2 crossbar.
- Bend or out of column bearing plate.
Possible corrective adjustments considered:
- V frame tension pulling up on the cup could raise (fraction) the drum relative to the bearing plate. It is possible that the V frame is pushing down. V2 adjustment should normally be a net fit, neither pushing down or pulling up.
- Raising the base pin inside the receiver, possibly with washers under the pin hardware inside the cup.
- Adding material on top of the pin or inside the mast base (teflon chip similar to Hobie 14 / 16?)
- Replacing the base or re-positioning.
Thanks Matt. Please thank the Hobie Geeksquad for us too.
That's a pretty good list of the variables. I might add "over time, stretching and deformation of the hull (bottom) can slightly lower the mast cup if enough positive turnbuckle pressure is applied."
Ultimately, the position (and any subsequent movement) of the glued furling ring is the most important factor. Together with the rest, it could contribute to the small but important differences we see from hull to hull, and sail to sail.
There are slight issues with a couple of the provided solutons though:
- "Sheeting out and then furling should correct that one." This may only work in North America. In Australia, the men don't know how to furl.
- "Raising the base pin inside the receiver, possibly with washers under the pin hardware inside the cup." It can take quite a few washers to make this calibration, as we initially found when adding stainless fender washers under the sail to raise it. My feeling is that these base screws are too brittle and that raising the step plate will loosen or weaken the connections where forces to the pin are frankly, incredible. Having seen a couple thick base pins shear would lead me to rule out that fix on my boat.
Can we ask you for a little more info?
1. Is the female mast (or the male for that matter) designed to rest and spin on the bottom of the cup, or float over it, suspended slightly on the pin?
2. Can Hobie provide the critical measurements for the distance between the mast base (either gender) and the bottom of the furling ring? It seems to me, this is the first thing we all need to check...
Again - Mahalo Nui