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

Nah, but if they don't know how long the piece is, they could find out by measuring how much is left. If they knew how much was left they could just subtract that from the original length and thereby derive the length of the piece, unless more than one piece were removed from the original whole piece. Capisce?

Happy New Year!

 

MPX Test Model

MPX Test Model

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Interesting comparison of the Flying Phantom with the fullsized version of the MPX Fire Arrow:
Flying Phantom:
1-LOA 18'
2-Beam 9.8'(+two on trapezes)
3-Sailing weight- 713lb including two 175lb crew
4- Sail Area(Main +Jib) 252 sq.ft.
5- Weight/SA= 2.82 pounds per sq.ft.

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MPX Fire Arrow:
1-LOA 18'
2-Beam 22'
3-Sailing Weight-750lb including two crew(Note: can be sailed single handed in winds up to 15 knots. Crew sits in very comfortable bucket seats and never moves further than across the cockpit-about 4')
4-Sail Area(Main + Jib) 310 sq.ft.
5-Weight/SA= 2.42 pounds per sq.ft. double handed / 1.85 pounds per sq.ft. singlehanded.
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And from post 831: (please read post 831 to learn more about whats going on in this thread)

Comparison of Righting Moment between Flying Phantom and the fullsize MPX trimaran foiler

Illustrations-click for better view:

 

Well seems to me that if I'm cutting string for a halyard, I know exactly how long it is - because... well because I've planned it out.

Then again if I keep trying to make the halyard by randomly splicing bits of unrelated string together, you are right, I'll have no clue...

hmm maybe you are onto something here.

 

Doug what is "center of lateral pressure"? if you are talking about resistance to leeway that is Center of lateral resistance, but if that's the case, your drawing is incorrect.

your ama foil generates laeral resistance so it contributes to the heeling moment force couple. Using the main foil for the pivot point is valid for a mono-hull. It is not a valid analysis for a multihull. If it were, mutlis would not flip

 

Lol Guys.
Boggles the mind.
Anyway, best to you all for the New Year.
Paddy.

 

+1

+1

 

But doesn't that require actually wanting what's left to come to an end?

 

Tie a knot in the end, but not the bitter end. A hitch would be more appropriate there.

 

Tying a knot still implies a desire to come to some sort of stop - albeit if only temporary step in future measurement

 

Just took another look at John Xman's project which is fantastic-12' wing ,86" hulls. He has found a source of servo's and custom parts that I hadn't known about-ServoCity. Still don't know much about them but they have an incredible array of specialized rc products-http://www.servocity.com
Theres a link to Johns project on page 35 of this thread, post 520.

 

Also see post 522 for more about this old video and the RC boats I designed, built and produced including the F3 foiler.
http://www.youtube.com/watch?v=BRJDrWSZE6o&feature=youtu.be

 

Doug, do you have a website or a blog?

 

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Just this one-why?

 

I was wondering because It looked like you are using a forum as a blog. Why not just get a blog? People can still leave comments on blogs, and it would allow you to avoid the "responding to yourself" syndrome.

 

MPX Test Model

Interesting to take a look at the actually L/B ratio's of existing multihulls and the MPX/SRT. The MPX ama without the modified planing surface is about 13/1 and with it about 7.35 . Length/Beam ratio is dependent on ,among other things, the weight the boat is expected to carry which explains why most multies under 20' have L/B ratios substantially under 20/1*. Cats always have to be figured on the basis of the lee hull supporting all the weight depending on any lifting foils that might be used. Same true of tris except that most tris under 20' do not fly the main hull and several use planing main hulls.
*In fact, I'm not familiar with a single cat under 20' LOA with a L/B ratio of the lee hull carrying all the weight that even comes close to 20/1!(maybe an A cat?)
I don't think I mentioned the Moth hull -about 11/1 and before foils it would plane at about 15 knots if I remember correctly. The Moth guys found that the relitively skinny 11/1 hull outperformed semi-circular hulls with less wetted surface proving, to some degree, the importance of L/B ratio