Little Things

I'm actually pretty surprised how well Mothball One is holding together. I have had a variety of breakages, buts its all been pretty minor stuff, not the huge splintering carbon fiber carnage I was half expecting to happen. I took the boat out last night for an evening sail in 10tks with some gusts around 20. That was by far the most wind I'd been out in, but she seemed to handle it ok. The boat foils great. Once its up it pretty much stays up till the wind dies or I crash. Unfortunately my sail was cut short by another small breakage. After crashing the boat in a gust I was arranging myself to bring it up and I somehow kicked the wand forward and broke the front rod linkage. Foiling over. It was a stupid little problem and a stupid mistake on my part for breaking it, but the linkage is probably under-built as well. So is the general rule just to stay away from the front of the boat in a capsize to avoid screwing up the wand? I'm also considering adding a rotation limiter on the wand to keep it from being pushed too far forward and stressing the mechanics. Little things, but I hope I can get them all sorted out and really start to learn this boat.

Flying Pics...Finely

It was a really nice weekend, just not a great weekend for mothing. It was hot and sunny but the winds were 3-5kts pretty much all weekend. Except for a brief period yesterday afternoon it was not possible to foil. But I did a bunch of lowriding practice which is probably a good skill to have. I must say that it is remarkable how much faster the boat is in lowriding mode when you disconnect the wand and reduce that AOA on the rudder. At one point my rudder came off, but I was able to reattach it with a bit of help from a jetski. Luckily I was able to take a few picks of my brother sailing late in the day when the wind picked up to a whopping 7 kts and the boat was just able to get foiling. Clearly the ride height isn't great, but that may have been due to the wind. I did extend the wand a bit today with a plastic spoon handle, but there wasn't enough wind to try it out. This week I hope to make a few modifications to prevent the tramp strings from breaking a keep the rudder from coming off again, but all in all the boat is working great. I can't wait to sail it in more than 10 kts of wind.

FIRE!

Tried to go sailing again today but the lake is on fire. Freek'n a man!

Design Notes

I wanted to write a bit about the things that I learned while working on Mothball in the next few posts so I'll start with materials. Woods is a great building material, its cheap and easy to shape and is quite strong. Wood is natural carbon fiber after all. If designed and used correctly its probably nearly as strong as a composite hull and nearly the same weight. So how come no productions boats are made out of wood any more? As far as I can tell its probably mostly to do with how long it takes to build a wooden hull. If you have a mold you can create most of a composite hull in a few hours with great consistency. A good wooden hull takes much longer to build and shape and will have natural inconsistencies. So the money saved in materials cost is lost in the extra fabrication time of a wood hull. If you have a ton of time and don't have a mold then a wood hull makes a lot of sense, but if you were producing hulls commercially a wood hull simply is not practical.

Carbon fiber tubes rock. They are actually really easy to work with. Just cut, bond, reinforce the connections and you're done. Carbon tape is your friend. Kevlar is nice, but is a pain to work with. Its really hard to cut and impossible to sand, well you can sand it but it always leaves hairs. Good old fiberglass is nice for doing finish work because its much easier to sand and finish than carbon.

Resounding Success!

Today was the first real day of sailing on Mothball 1 and I must say that it was a resounding success. After a marathon repair session yesterday we fixed all the broken parts and reassembled everything early this morning. My brother had to leave early so I let him go out first. I tried to follow on his keel boat but the motor crapped out so I couldn't take any pictures. He came back in and was surprised that the boat had taken off and foiled instantly. I was surprised too. He needed to leave so I went out on the boat and spent the next two hours on the water foiling most of the time in a nice 8-10 kt breeze. The boat feels great. Surprising good actually. The wand response is good, the rudder foil adjusts well and trimming the boat is easy, the rudder is surprisingly balanced, the rig works fine, and the only thing that broke is was one tramp string. I even tried to pull off a foiling jibe, it failed miserably but whatever. I was expecting to have major mods to do after the first real sail, but all I really have to do is inspect everything to look for problems areas and do some refinement on some of the systems.

First Flight

Mothball 1 has officially had her first flight, it was somewhat brief, but she did fly. I got everything rigged up this morning and hit the water early, the wind was pretty light on the first run and I broke some of the lines on the tramps so I went back in to fit it. When I went back out the wind was up a bit and I could tell she really wanted to fly. The rudder wasn't giving quite enough lift so I had to move way forward to get the boat out of the water but she finely took off and flew for about 10 sec until I ran out of lake. I tacked and headed back the other way and she took off again and really started moving. Everything went quiet and the rudder got really sensitive but she was off and she felt good! Then POW! The sound we all hate to hear. The boat crashed back to the water relatively smoothly and I kept sailing trying to figure out what had broken. The foils were still on, the rig was up, everything was in its place, but she clearly wasn't interested in going onto the foils any more. A brief inspection at the dock revealed the problem, the daggerboard had separated down the middle. Apparently I hadn't bonded the two sides together well enough and it just cracked. Luckily there wasn't any major damage. Spent the last four hours re-bonding the sections and its back out to the lake tonight. I'm kind of amazed this thing actually flew without making any major adjustments on the first day! Yay!

Moth Lube?

The SS rod is done. All thats left to do attach the rotating pin in the flap and do final adjustments. Friday will be the day for the test flight. Yay. One quick question, is there a recommended lube for all of these moving part?. Everything on the boat is reasonably low friction, but I figure lube is always good. What do people generally use for lubing the push-rods and such?

Foiled Again!

For a variety of reasons, my goal of foiling this weekend will not be accomplished :( There are several reasons for this, not the least of which is the fact that the guys at the machine shop did not come through with the parts, but its also the July 4th weekend, my daughters birthday, company is coming, bla bla bla, so maybe this is best anyway. The good part here is that instead of rushing the last few jobs and then splashing the boat I should be able to do a bit more refinement over the next week and I promise next Friday will be the day. I even ordered some additional fiberglass rods yesterday to ensure that I will have a functioning push-rod available by the end of next week. The glass rods may not be as good as a stainless ones, but it should be good enough to last a day of beginner mothing if needed.


But speaking of foils, check out the mostly finished products. They still need a small amount of fairing and need to be pained, but should be quite functional and honestly look quite nice. I added the bullet on the main strut at the last minute, but it turned out really good and should help make the joint stronger. The thing seems pretty stout, I didn't test it to destruction but I pulled on the ends pretty hard and it gave no sign of even flexing. Do note that the rudder seems to be slightly longer than the daggerboard, this was just a function of how they got assembled. Once installed on the boat the foils will be pretty much in line going through the water. The rudder foil is currently screwed on so I can change the length if necessary. Does anyone have an opinion on having the rudder slightly longer or shorter than the daggerboard?