Thought experiment

What works and what doesn't. Share design ideas, references and contacts for paipo board builders.
CHRISPI
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Thought experiment

Unread post by CHRISPI » Thu Aug 17, 2017 11:57 am

My next crack pot experiment .Concaved scroll wedge v twin
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bgreen
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Re: Thought experiment

Unread post by bgreen » Thu Aug 17, 2017 5:30 pm

Chrispi,

This is a radical looking board, especially the tail view. Is it meant to be ridden finless? I ask this because there is a lot going on, on the bottom.

Has the other board been glassed.

Bob

CHRISPI
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Re: Thought experiment

Unread post by CHRISPI » Fri Aug 18, 2017 6:24 am

Bob
The scroll tips will grow about 10 mm when glassed, sort of finless. The other board has its deck pad on, but I am battling to finish the clear coat we are having cold wet weather for the last 4 days battle with runs when it’s cold.

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Re: Thought experiment

Unread post by bgreen » Fri Aug 18, 2017 8:05 am

You are quite right. I wasn't sure if you planned to add fins as well.

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Re: Thought experiment

Unread post by GeoffreyLevens » Fri Aug 18, 2017 9:43 am

I don't know doodely about hydrodynamics but won't the concavity down the center, between the scrolls, since it narrows as it goes back, create a lot of drag? All concaves I have ever ridden open up towards the tail... I'd love an explanation of any theory or if you have already ridden something at all similar.

CHRISPI
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Re: Thought experiment

Unread post by CHRISPI » Fri Aug 18, 2017 10:26 am

Good question a prone board rides about 15degres off centre to the wave face, I am trying to harness the wash energy that is normally lost outwards. I have never been happy with concaves that exit parallel with the centreline.It’s also an inverted keel ,told you it is a crack pot experiment

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Re: Thought experiment

Unread post by GeoffreyLevens » Fri Aug 18, 2017 11:23 am

Definitely an interesting concept and a cool look. Eagerly awaiting ride report!!! Always good to remember that those crackpot experiments sometimes yield pure gold.

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Re: Thought experiment

Unread post by Pes78 » Sat Aug 19, 2017 11:04 pm

Thank you for the inspiration Chrispi. I was going to go with a flat bottom with maybe a little vee in my next board, but you have changed my mind. I need to just go for it on this next board with what I'm going to do. Plan on doing the bottom I did on the finless board I did early this year and really spoon out the deck. Thank you.

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Re: Thought experiment

Unread post by CHRISPI » Sun Aug 20, 2017 11:04 am

I make miniature models to visualise the board in the blank before I start cutting , I use 50 mm ESP sheets, and I think moulded surfboard blanks restrict innovative shapes
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Re: Thought experiment

Unread post by Pes78 » Sun Aug 20, 2017 5:44 pm

If you getting the insulation sheets and glassing yourself I assume you can get away with that. The blank I'm getting is a mould but also not a close tolarance blank like you would see from US blanks. I'll admit here that I'll be cheating with the next board by not doing a outline just cutting 6" off the tail and a 1/2" from the nose. Going to focus my energy to spooned out deck.

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Re: Thought experiment

Unread post by CHRISPI » Thu Sep 14, 2017 6:12 am

My first wingless boards, so easy to make compared to the wing boards. The white decked board has been tested in very good conditions 1.5 m @ 11seconds off shore, very easy to get comfortable on not like the wing boards that take at least 3 sessions to work out, very well balanced board, tracks well no need for fins, it’s hard to be objective comparing it to the wing boards, I am suffering information overload
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CHRISPI
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Re: Thought experiment

Unread post by CHRISPI » Mon Sep 18, 2017 7:50 am

Both boards tested in fantastic surf. The white decked board faultless, black decked board is ok , pulls great cutbacks not as directional, fells lose not tracking as well down steep faces

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Re: Thought experiment

Unread post by bgreen » Wed Sep 20, 2017 5:47 am

Chrispi,

Sounds like the boards go better without the wings. An interesting opportunity to test new designs - in good waves. What are the dimensions of the better performing twin-keeled board?

Bob

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Re: Thought experiment

Unread post by CHRISPI » Thu Sep 21, 2017 6:33 am

Bob
All my boards are about the same size, 46 in long, 19 in tail, 22 in widest point. I am blest in Durban lots of good warm water waves to test on. Are the wing less boards better than the winged ,wing less don’t handle choppy faces as well , and get pushed out of position by collapsed sections , the winged boards blast through collapsed sections so I make more waves. Off all the boards I have made the white decked board is the first that felt perfect from the first wave

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Re: Thought experiment

Unread post by bgreen » Thu Sep 21, 2017 1:30 pm

Thanks. Confirms the theory that there is no perfect board.

The big question - what is next?

CHRISPI
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Re: Thought experiment

Unread post by CHRISPI » Thu Sep 21, 2017 2:26 pm

It confirms that I have no cooking clue about understanding riding an incompressible fluid wave

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Re: Thought experiment

Unread post by GeoffreyLevens » Fri Sep 22, 2017 9:10 am

CHRISPI wrote:It confirms that I have no cooking clue about understanding riding an incompressible fluid wave
Probably will require quantum computer modeling to even come close. The best (for now and likely for always) is your approach, intuitive experimentation based on direct experience. Pioneers may get arrows in their backs but they also make to edge of the map discoveries!

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Re: Thought experiment

Unread post by Nels » Fri Sep 22, 2017 8:41 pm

Keep the "thought" in "Thought experiment"...if it makes you happy then you must be doing something right, even if it's wrong...

Nels

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