Time for an Upate

Where has MB1 been this summer?  Well sailing actually.  So far this year I've logged over 100 miles on the foils.  The boat is working great and I'm starting to feel pretty confortable at the helm.  My tacks and jibes still have a long way to go, but I'm pretty sure that I could race the boat now and not make a fool of myself.  I'll post some more info about the mods I've made this year over the next few days. 

As a moth sailor all I can say about the flying AC72s is Fuc$ Ya!

Stainless, Brass, or Carbon?

I’m in the process of building a new gantry out of carbon.  It looks really good (pics soon), but I’m planning on upgrading my rudder pin in the process.  Right now I’m using a ¼” stainless pin which has worked fairly well, but I’ve bent it several times so I don’t think it’s really up to the task.  For a replacement my choices are 5/16” stainless, brass, or carbon rod.  Stainless is the most obvious choice but it seems like brass may work just as well and is far easier to work with. My other choice is a solid carbon rod which would be way lighter than the metal rods but I’m not sure if it would be up to the task.  Carbon would also be able to flex without bending and could shear off without damaging the rudder.  Any advice?

Space Moth

I was looking at Google Earth yesterday and realized that the satelite photo of my area had been updated.  It was clearly a summer photo and the lake was busy so it must have been taken on a weekend.  After a bit of searching I found Mothball 1, unfortunately I wasn't sailing.  The boat was under its cover in the rigging area, so I must have been getting ready to sail.  Can you find Mothball 1?

Upward Force

I have a new question for all you Mothies out there. How much force does it take to hold the daggerboard down while sailing? I’d think that there must be quite a bit of force upward on the daggerboard while sailing between the weight of the boat crew and acceleration forces. The reason I’m asking this is because I need to re-design my daggerboard box to work with my ride height adjuster. The daggerboard box on Mothball 1 is a 1”x 8” rectangular reinforced box that has a tight insert that bolts into the daggerboard box at the top to kept the foil from raising above the deck level. Then I had a pin that mostly kept the daggerboard from falling out while sailing. However, I need to change some of these parts to make the ride-height adjuster work and that includes cutting off parts of the daggerboard box insert and many of the areas that bolt the insert to the boat. Clearly I need a major re-design here. So the questions remains, what’s the best way to hold the daggerboard down? The two best options I see are to simply beef up where the pin goes through the daggerboard and assume that it will hold up. But my other idea is a bit different and seems like it would be much stronger. The other ideas is to bolt a removable flare onto the daggerboard at the bottom of the hull, so instead of holding the daggerboard down from the top with a pin, the flare would push up on the bottom of the daggerboard box in an inset receiver and prevent the foil from moving, then I’d just pin it on the top again to keep it from falling out. I kind of like the flare idea because I could make the foil/hull interface much stronger and stiffer utilizing the beefy rectangular daggerboard box originally designed in the boat. How do other boats deal with this?

Boat-Work Season

It’s still a bit cold to begin sailing in Montana, but ski season is officially over so let boat-work season begin! Thankfully most of my projects this year will be easy, I want to re-finish pretty much everything and make a few mods/improvements, but nothing too drastic. One of my projects for this year will be to construct a new rudder gantry. I must say that the original gantry that I fabricated out of solid oak was probably the strongest thing on the entire boat. After two years of useit never had a single failure, but that’s probably because it weighs a ton. Going to a carbon gantry will save me a lot of weight. So now I’m trying to figure out what diameter and wall thickness I need in a carbon tube to give me good weight savings but still be reliable. Is there a standard recommended size for gantry tubes?

2012 Projects

Now that Mothball 1 is stripped down for the season I’m starting to think about improvements and mods for 2012. Some of the modifications I’ve already started. Let’s start with foils. After checking out the information on Bruce McLeod’s blog (http://www.teknologika.com/mothblog/the-evolution-of-moth-main-hydrofoils/) I concluded that my main foil was too big. It was about 10% larger than the Bladerider main foil. Enter Mr. Dremel. After inspecting the foil and comparing it to all of the other foils out there I decided that my flap was too large, in particular at the tips. I couldn’t take too much off the flap, but I did taper it down 10mm at the tips. This should bring the flap into better proportion with the cross-section of the rest of the foil and reduce drag. Tapering the flap reduced the total area by 5%. I’m considering cutting the tips down a bit to reduce the area even more, but I may wait a bit for that. Does anyone know the approximate area of the M2 foils?

I’ve also decided that I want a ride-height adjuster. I can get good height, but it seems like I always have more height sailing downwind. If I set the height for downwind then I’m a bit low upwind, and if I set it good for upwind then downwind is horrifying. Is this normal? I saw the ride height adjuster on Sailingbits.com (http://www.sailingbits.com/catalog/moth-ride-height--gearing-adjuster-p-377.html). Does anyone know if this adjuster will fit onto Bladerider components? Seems like buying one of these would be way easier than developing my own system.

These are my only two big planned changes. I want to refinish the hull and make some other minor repairs, but these are relatively easy. My hope for 2012 is to get things sorted and then make it to some Moth events on the west coast.

End of the Road

This weekend was the last mothing in Montana, and a beautiful weekend it was. The breeze was a bit variable, but I did get a few good sessions. My last sail was in 7-10 kts of breeze and I logged 14 miles in 1.5 hours at an average speed of about 10 kts. I also pulled off four fully jibes and didn’t ever get the sail wet. I’m to the point I’d feel pretty comfortable taking Mothball 1 somewhere to race and I don’t even think I’d embarrass myself. But for now it’s time to start thinking snow (forecasted for Friday). Mothball one will be fully stripped down and prepared for a full refinishing next spring. I have some ideas for mods and new parts, but I’ll save that for another day.