I always thought all of this talk about optimizing gearing was a bit of a wank. Well N4rks and I adjusted the lever off the wand to try making the boat take off sooner. Whatever we did has turned this nice happy docile boat into a angry monster.
I spent the whole day pitch poling and struggling to get downwind in about 16kts of breeze. I probably spent as much time on my side as upright. N4rkla took the folloiwng movies. It shows a number of typical pitchpoles.
Can anyone suggest what is going wrong? With the exception of the last clip it doesn't look like the vessel is flying too high. I'll try to get access to a better video camera for next time I go out.
Ok this is an educated guess but as you have changed your wand I would think that you are going full flap up almost instantaneously, and you are stalling out the main foil and then loosing all your lift, then over you go.
ReplyDeletethat sounds reasonable.
ReplyDeleteYou defiantly don't look too high. The first clip hardly looks like you’re out of the water.
ReplyDeleteI would tend to agree that the flap is coming up too quickly. The last one looked like you had pretty steady flight until you came up a bit then crashed. If it wasn’t doing it before you changed something then change it back.
Good Luck,
think about the slack in the system too, because in any case the foil should start lifting again when you pitch down a bit. unless the flaps not going back down.
ReplyDeletemaybe try lengthening the pushrod a bit also? at a guess. boat looked pretty good when going straight and normal
Does it happen when you sail upwind or only off the wind?
ReplyDeleteAlso would be great if you could post a pic of your wand pivot, where the pushrod comes out of the hull..
ReplyDeletelooks to me that a pushrod is buckling
ReplyDeleteSounds like a good assessment but I wouldn't take this guy Bora too seriously as I don't think he has any experience with foiling moths.
ReplyDeleteno experience with foiling moths eh?
ReplyDeletehttp://www.mothworlds2009.org/2009CSTMothWorlds1.15.htm
Anonymous doesn't seem to understand sarcasm! :-)
ReplyDeletemmm, lots to think about. we will thoroughly test the linkage system this weekend for buckling, throw/ratios and slack.
ReplyDeletedid the testing on saturday (no wind) and results will be analysed shortly and published.
ReplyDeletethe front foil might be washing out too
ReplyDelete