High Performance MPX Foil/Self-righting Trimaran-The Test Model

MPX Test Model

I made the decision Thursday(wind forcast for 7 days : above 10 knots) to go ahead with the detailing of the boat starting with re-aligning the rudder and temporaily bonding the gantry into the stern tube on the stern. Last time I did this I managed to knock it loose taking the boat outside. So this time I used a bit more epoxy putty which is going to have to be ground off and the surface touched up. Next step is drill the gantry and stern tube for the removable fasteners.
The alignment is to get the rudder and daggerboard in exactly the same plane and to check the main foil and rudder foil angle of incidence. The main is at 2.5 degrees and the rudder at 0 degrees. The thing can now be disassembled for transport and reassembled exactly at the beach. The main foil can be adjusted to a greater AOI if required after the first sail.
And the "icing on the cake"(NOT) : it was flat calm all morning but the boat couldn't be moved to set up the rig!

 

MPX Test Model

Finished the rudder/gantry system today. The rudder retainer pin is a carbon tube that fits in the stern tube very tightly. It's so tight that it needs to stick out far enough to be able to be effectively gripped by hand. Can't grab it with pliers or vice grips because the tube would crush. It can be removed relatively quickly so the rudder +gantry can be removed for transport:

click--

 

MPX Test model--Heads Up!

Be sure to read the updated summary above under "MPX Foil System". Go to the referenced post and follow the link for some experimental results that tend to back up my theory on how the ama foil will work with small amounts of leeway.

 

Less Talk More Rock!

 

MPX Test Model

Well, I'll be damned......it's Himself!

 

MPX Test Model

A small problem was solved today when I figured out how to protect the ends of the "plug-in" carbon tubes-where the ama tubes plug into the main hull tubes. I've planned on using my "super lube" on the joint to make it easier to assemble and to keep water out. It's a clear "grease" that works real well on this kind of application. The problem is that since the boat will be assembled and diassembled on a sandy beach keeping sand and other stuff off the grease is important. If I had to, I was going to use aluminum foil, but I came up with a much better solution: for the main hull side I'm using vinyl caps that fit tightly over the tube; for the ama side I found foam "grips" sold by McMaster-Carr that cover the insert completely. They should be here tomorrow.
I haven't done this before but I'm stumped: how can I very simply hold the ama's to the main hull? If you have an idea please let me know-here or by PM. I've considered "water stays"-too complicated and too much likelyhood of causing drag. I've consider just putting a screw from the main hull tube thru the ama tube-this is the leading candidate right now but I really don't like it. I tried using the waterproof aluminized tape I have for the radio box but when I tested it, it had no strength at all. So do any of you guys have a good idea?

Pictures,L to R--aft tubes, fwd tubes, amas:

 

Lashing. 2 or 3mm Roblon whipping twine 3-4 passes over the amas and under the hull.

takes 7-8 minutes?

 

.....

 

MPX Test Model

"...over the amas and under the hull." Ah, riiight. Thanks(!)
I might be able to use the 150lb spectra and just tie it to the ama tube and then tie the other end to a turnbuckle* thats fastened to the main hull tube. hmmmm.... I don't need the line to go at an angle like a water stay....

* these very small turnbuckles are pretty cool: they open and can be re-attached at the same tension they were originally set at--

 

...

The 150 lb spectra?



Any more procrastinating perfectionism out of you Doug,
and we're all going to commit a sort of collective forum-Hara-Kiri,
jumping off the nearest cliff, in the thread started by Pipeline!

lol

If you don't think it looks perfect, it doesn't matter, it's a model!

 

MPX Test Model

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Thanks, Magnus! I'm leaning toward the turnbuckles-heavier but very quick to
attach and take apart. Got to think about it a bit......

 

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You need to stay away from cliff's for a couple of weeks or so..... Oh, and I have 500 lb spectra-both are very small diameter and "normally" used for kite lines.

 

...

Pipeline, are you reading this?

Have you got space in your Hawaiian beach bungalow

for just one night?

 

Doug, drop the ******* thing in water.

 

MPX Test Model

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Thanks, Gary.....