The period since the Nationals has been very busy, with non-sailing activity acquiring all my spare time, which also included changing jobs.
Now that things have settled down a bit, I thought that it was time to provide a de-brief of what has happened since the foil conversion was completed, and share my pain with the world as my boat still hasn’t foiled.
I must say, even though I am very disappointed that boat didn’t foil at the first attempt, I am not totally surprised. The goal of building a set of foils and expecting to get the setup 100% correct the first go is a pretty unrealistic expectation.
So what is wrong? Well there are a number of factors that I think are combining to prevent the boat from lifting off: weight, foil angle, and rear foil size. What has become evident from various peoples experiences at the national titles with conversions is that angle of incidence is critical. As it turned out, the centreboard case filler that my board slots into has my angle at around -2°, where as the majority of the fleet had angles from 0° to +1°. To “sail around” this problem, I would consistently have to sail with a 3° stern down attitude compared to the other foilers. That conveniently leads onto problem number two … the rudder.
Ok, I’ll be the first to admit that my rudder foil is HUGE. It is around 1m in size, and I always planned to cut it down in size if I needed to. The reason that I made it so big is A) I used one mould for the rudder and centreboard and B) With the extra weight that I am carrying compared to guys like Rohan Veal and Scott Babage, I figured that larger foils = earlier takeoff, but lower maximum speed. The problem is that with the large rudder, combined with a non-zero degree angle, equals too much lift at the stern, so when even hanging off the back of the boat, I was unable to get enough positive angle of incidence lift to haul the boat out of the water.
The other minor hiccup is that my centreboard snapped clean in half at the bottom of the hull in the second last race of the series on a reach in 25 knot winds, and I need to make another one …

Interestingly, Phil Stevenson had an identical failure in the same race.

Posted in: Foil Construction, News | 3 Comments →March 15, 2006

October 14th, 2006 at 12:35 pm
hi my name is josh mcknight and i was just wondering what u did with that foil u distroyed and if i could have it or take if off your hands for u if that would help. i could pay you for it if that would be better
October 15th, 2006 at 10:46 pm
Josh,
I am curious as to what you want the broken foil for?
I still use what I have left of the foil. The part that is missing is at the bottom of Lake Macquarie, north of SLMASC. If you want to go diving and retrieve it, it’s all yours.
Bruce
November 11th, 2006 at 12:22 pm
do you have a mould for the hydrofoils?
how much do you want for the mould?
i want the broken hydrofoil for a wake board or surf board or to add to my flyingeleven for a project of my own and to be the fastest flyingeleven in 15-25 ktsand have fun like all mothies do
do you know any one that has a mould of any sort?
josh mcknight