DaggerBoard Design Simplified?

Yeah it holds according to them, looks like they are a pretty serious company, check their site. I will investigate more next year when I am at that stage.

Good to know on the other stuff!! I think I would cnc the molds out of mdf, cheaper and faster. I will have to make a couple of extra to take with me, once I take off, I won't be back for a long time! or at least that's what I hope.

Thanks for the input.

Here is a video of them putting Micanti on a large commercial ship
https://youtu.be/XKo4KUpwvn4

 

Yeah but how does it stay where the surfaces are rubbing, interfacing etc? you cant have that stuff where the running surfaces are sliding over one another...

 

I see what you're saying, I might be able to recess the case like 1.5 mm, just in the area below the waterline (about .5 meters) starting about 8 cm up from hull line so I could keep that bearing point. Then I could anti-foul that.

Actually I know I guy who ties a garbage bag on his prop and shaft and that does the job perfect so I will just stuff a garbage bag up in there or make a plastic plug for when I am at anchor.

 

It depends on the foils honestly. You can't grab dagger boards from a NACRA and use it on a Gunboat 55.

Probably the most expensive small cat foils on the market right now are A-Cat Z10 boards, and they only run about $1,500 each. Figure out the cost of 12-15lbs of UTS prepeg carbon, amortize the molds, and add in the labor and autoclave time they really aren't making much per foil.

A lot of classes do use extruded foils (not machined). It's far cheaper if you are going to sell a lot of foils to pay for an extrusion mold and add a handle to the top than to build a spine like you have designed.

As for $30,000. I think that was the additional cost for a 40' cat with daggerboards and without. Add in the foil cost, the trunk cost, the extra labor, it's really not that much just for the foils.

 

Interesting, what material do they use to extrude?

 

Aluminium of one alloy or the other. The cost is really in having the dyes made, but once you do the foils aren't much more than aluminium tubing (by weight). Basically the manufacturer just orders 20' lengths of the profile and chips them to length, it's a pretty quick and painless process.

 

He only needs two boards, why not make the mold out of plaster or concrete? You can cut the (half) profile out, bend a sheet over it stiff enough to pour concrete over. If you look you will find decorative concrete techniques for smooth high gloss finish.

 

He doesn't say the daggerboards are $15K a piece. He says two daggerboards add $30K to the cost of the boat. That would include the boards, trunks, extra labor, hardware, etc.

 

Thanks, yes, it's been cleared up.

Thanks for all the info, got it cleared up now.