Long Beach Regatta April 17-18

The NOR for the regatta at ABYC is posted here: http://abyc.org/upload/2010_Moth_Invitational_NOR.pdf

There will be online registration, I'll work on getting that set up. We've already got six boats at the club that got shipped from Hawaii, and there will be more coming from Worlds, so we're looking at a minimum of 13 boats or so. The racing will be Saturday and Sunday, but I'll be sailing most of the week in the afternoons. We usually have good breeze, so its a great place to start you're training for Belmont!

I've got some pics of my new extendable wand I'll post soon.

Helicopter Assisted Sailing

Had a great week in Coronado for the PCCs. It was the first time I'd sailed with the good US guys, and it was an awesome learning experience. It seemed like that boat was going ok, most of my issues were in my boathandling and not boatspeed, which is encouraging, I even managed to sneak into the top ten a few times. I pulled of my first foiling gybe ever sailing out for the first race on Friday, and managed to make more gybes upright and foiling than not over the course of the weekend. I'm going to try do do as much sailing as I can while everyone is off to Hawaii and then the Worlds so that I can be up to speed when the boats get back.

The conditions through the week were a mix of lowriding and foiling, but overall you couldn't ask for better during the winter. The thing that made the whole experience was the Coronado locals, with Charlie hosting a great dinner and organizing the regatta, and the Henkens providing housing to half the fleet as well as their usual amazing hospitality.

I've progressively cranked on the angle of attack on the mainfoil and have been foiling more and more bow down as a result. The rudder is longer than the daggerboard, which seems to be a good call, as the rudder has yet to ventilate even at extreme bow down angles. The boat is definitely more draggy when lowriding, bringing to mind thoughts of on the fly mainfoil angle of attack adjustment... The fact that I don't have a dial to take off flap angle when lowriding doesn't help much either. These issues have started a lot of thinking about different wand linkage systems, but I'm going to try to stay pretty conventional while I figure out how to actually sail the boat

It was cool to see how the guys have developed their light air foiling technique. I think it made the light air races much more interesting, and it would be a shame to make everyone sit perfectly still and lowride when they could be flying. I managed to get a nice boost from one of the Marine helicopters that was circling around the racecourse. In pretty much lowriding conditions, it left what felt like a 15-20 knot puff behind it which needless to say, easily popped you up on foils. Maybe I've found my perfect light air foil technique, the fuel bills could get expensive though.

Infestation

We had six moths sailing yesterday at ABYC, which I think is the all time record. The coolest thing is all the boats were local boats, which bodes well for the future of our fleet. I hadn't sailed my boat in foiling conditions in over a month and felt really rusty. We were all in a similar situation as the weekends have been decidedly lacking in wind for the last month or so. It was a good chance to get the feel back before we head down to San Diego next week. I'm really looking forward to making big gains in my skill level, and I think I'll be able to get down there on Tuesday and sail through Sunday. Anyone else gonna be around early in the week? I'm bringing as much of the shop that will fit in my car. Vacuum pump, carbon, epoxy, jigsaw, etc so that I hopefully don't have to make the 3 hour drive back to Long Beach to fix anything mid week.

The pics are from some sailing in San Diego I did a while back. Looking forward to the flat water of South Bay, I've heard rumors of 20 boats showing up.

Foil Setup

After listening to the latest mothcast I decided to check my main foil angle of attack. I made a template of the foil section and drew the chord line and lines at 1.5, 2.5, and 3.5 degrees. It slips over the tip of the foil. I added some thickness to the trailing edge and did a really quick and dirty job of fairing the thickness into the flap. I've got it in pdf and dwg formats, so if anyone wants it I'm happy to email it to them. It plots on a letter sized sheet. I used a laser level to get the boat level and then shot it on the template. Wow, my foil was at not much more than 1/4 of a degree! That explains a little why I had to hike off the back of the wingbar and was sailing around in full flap down mode. I guess I was a little less than accurate in drilling the hole for my main foil and/or set it up at the wrong angle. I thought I was doing the right thing by putting the daggerboard at 7 degrees of forward rake, but apparently not. Needless to say, the boat sails a lot better now.

I didn't realize people would be so interested in the photo of Karl's boat. My attitude is that the more people that see your stuff the better, and I hope that everyone takes another look at the bowsprit concept. It's definitely on my list of stuff to do once I figure out how to keep the boat upright. The funny thing is that the bowsprit is possibly the least radical part of Karl's setup.

Flashes of Brilliance

A lot has happened since my last post.

I competed in my first moth regatta. It went about as well as I expected. Had some good moments, including rounding the top mark in second with a pretty big gap between me and the guys behind me (that ended when my vang blew up on the downwind.), and also had plenty of mechanical issues. The second gantry is holding up well so far, it does everything it's supposed to and hasn't self destructed yet. Richard won, and Paul came in a close second after driving all the way down from Santa Cruz. Karl's boat showed some impressive speed at times as well, I'm excited to see the further development of the tilt-a-whirl. Here's some pictures:

In other news, Chinchillazilla#2 was launched. Bobby worked almost non stop to get it done after getting back from South Africa. There wasn't much wind for the launch, but it floated, which is good. Richard took some pics:

The boat looks great!

Next up is the Turkey Day regatta in a couple of weekends. Should be great and we're hoping to get some of the mothies from San Diego to come up.

Gantry #2

So here's my second attempt at a gantry. Its got a different control mechanism too. I told myself when I launched the boat that I wouldn't change anything till I figured out how to sail it, but breaking my first gantry accelerated my development program a bit. The new one has held together through two days of sailing in 0-5 kts so still haven't been able to really put it to the test. The adjustment mechanism seems to work. The biggest problem is now that I can adjust rudder angle easily, it's easy to put it in the wrong place.

There's a million things I would do differently for the next one, and might get the chance to do soon, as Karl's new rudder is coming along and he's thinking about a new gantry to go with it.

It weighs about 725g with the adjustment mechanism which is about 200g heavier than the last one. I think I could get about 150g out of it easily for the next one. What's a good weight for a gantry?

Gantry #1 RIP

I've got five days on the water now and had my first major breakage. While blasting downwind my gantry decided it wanted to turn left while I was turning right. What actually failed was one of the attachments to the hull. This was two weekends ago and I've spent the last week and a half designing and building a new one. When I built the first one there was almost no engineering involved, so I decided I'd put in a little more time in the design department. I definitely underestimated the side loads created when foiling at high speed and how easy it is to load up the gantry with less than smooth steering (which right now is pretty much the only kind of steering going on).

The question is: how much load is there really? If you assume a Cl and speed for the rudder, you get a load that if applied to you and the boat, would quickly flip the boat/vaporize the rudder/accelerate you sideways quickly enough to make you black out. This doesn't seem to be a realistic load case. I think a more reasonable load case is applying the full righting moment and resultant sideforce to the rudder with a safety factor. Any more than this in theory would capsize you.

A second thought: how many gantries actually fail in buckling versus a failure of the attachment points/joints? It seems like it's pretty easy to design a tube for good buckling strength, but designing an attachment or joint that can handle all the multitudinous load cases is the tough part. Given my gantry failure data set currently has one point in it, I don't have much to go on. Anyone have any thoughts?

Congrats to Karl on getting married! I hope this doesn't affect his mothing time too much.

I'll post some pics of the new gantry as soon as its on the boat.