Author Topic: Cowboy Foil Experiment Thread  (Read 925 times)

surfcowboy

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Cowboy Foil Experiment Thread
« on: March 13, 2017, 12:57:28 PM »
A good old fashioned backyard build thread. I'll be making multiple versions but this is where I start and I'll track the next few prototypes and experiments.

Thanks to supUK for convincing me to start sanding, to Pono for his matching love of science and disregard for good sense, and surffoils for reminding me that a bodyboard is a lot easier to fall off of than a SUP.  ;)

This thread sponsored by Wile E Coyote.

Now, let's get into it.

Yes, I know it's huge. I can always cut it but adding wood is so much harder. It's scientifically designed by having a piece of wood this size. About 24" X 12". I wanted to see if the fore/aft stability of 12" would work with a body board but I'll be taking a bolt on fuselage and tail to stabilize it at the beach if this doesn't prove wide enough front to back to balance on.

I can also move it up and back as my board is a wood paipo so that should make on the fly adjustments at the beach easy as well. (Taking a buddy to assist, hold tools, and maybe film in case America's Funniest Home Videos or Red Bull, depending on the success or failure, is paying.)

The mount will likely need some beefing up and I'll also probably want to be able to stabilize it fore and aft so I can adjust the angle of attack. I'm thinking of using a threaded rod near the tail between the board and wing with nuts to adjust the AOA. I'm just sealing it with polyurethane for the tests so I can hack it up if/when I mod it.

I'd assume that after the first session I'll be cutting this down to about 6" and using the fuselage, but this rig will also accommodate a wider disc if I want to make one for single foil testing as we have discussed on the surffoils thread but this is sort of a mashup of his ideas, Terry Hendricks and then the GoFoil stuff if/when I add a tail.

The last shot is a mock up, I'm going to cut down the Paipo and then play with my balance point til I find a starting place.

What are you waiting on boys? Quit reading and start sanding!












SURFFOILS

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Re: Cowboy Foil Experiment Thread
« Reply #1 on: March 13, 2017, 02:57:54 PM »
You can, should, will foil on that easily, no problem.

surfcowboy

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Re: Cowboy Foil Experiment Thread
« Reply #2 on: March 13, 2017, 03:44:12 PM »
Ah, that made me day. I'll keep you posted and report findings.

Also looking for more aluminum to make a longitudinal foil set as well. I'm curious as to how small I can go on those.

SURFFOILS

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Re: Cowboy Foil Experiment Thread
« Reply #3 on: March 13, 2017, 04:26:18 PM »
24 x 12 = 288 square inches, you'll lift very easily, have great lateral stability. maybe a bit too much area for decent waves. Down to  250 on average waves, 200 for OH. Remove from the tips down to 13" wide,its like a bike- speed  brings stability.
Keep the supports in the middle of the chord and set itparrallel to the hull, no extra AOA needed, you'll find it's easier to control if the foil and hull are the same angle.

I mount with the TE 2-3" short of the end of the board for safety.
 You will have great fore/aft balance becuase you feet will provide stability.

Looking forward to hearing how much you love it.
« Last Edit: March 13, 2017, 05:23:09 PM by SURFFOILS »

surfcowboy

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Re: Cowboy Foil Experiment Thread
« Reply #4 on: March 13, 2017, 05:44:26 PM »
Thanks for the feedback. This is made for a pretty mushy test spot and then if i can manage this thing, I'll start working on chopping or making other versions.

I have a buddy who's a blacksmith so I'm going to get him to help me make some thicker aluminum struts so I can have a nice set in time.

I'm gonna go cut that Paipo down now and see if I can get this thing mounted and stiff enough to surf.

supuk

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Re: Cowboy Foil Experiment Thread
« Reply #5 on: March 13, 2017, 06:00:55 PM »
You can, should, will foil crash  :P on that easily, no problem.

SURFFOILS

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Re: Cowboy Foil Experiment Thread
« Reply #6 on: March 13, 2017, 06:10:20 PM »
Despite Supuks cynicism...  ::)

Even on waves that don't break you'll still lift up, it's about the area and the speed so you could paddle for knee high ripples and it will work.

 For years I used this 2 mm Al flat plate struts up to 4" high and 3mm for up to 8" high just like in the pic below and 3/4" wood screws. Don't even need to foil the struts, just take any edge off.

You don't need 'bulletproof',Go light and cheap and the shorter the struts the less dynamic forces on them.
« Last Edit: March 13, 2017, 06:13:59 PM by SURFFOILS »

PonoBill

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Re: Cowboy Foil Experiment Thread
« Reply #7 on: March 13, 2017, 07:07:41 PM »
Nah, lots of lift there. If anything your foil might be too efficient for that much area. I shaped the five sections of GF2 today, and I shaped the wing for the rudder/tail foil. This puppy is gonna be stout.
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Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

surfcowboy

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Re: Cowboy Foil Experiment Thread
« Reply #8 on: March 13, 2017, 07:38:29 PM »
Oh and I expect to crash. UK just has to give me some guff. ;)

Pono I figure I over did it but you know the deal there, I can always tune down. Also wanting to not have to get into too hollow of a wave to test.

I'm working on a safety feature that will need some collaboration I'm sure as well. I think I have a way to cut down the "tomahawk effect" of the wing foils.

Can't wait to see the GF2. That may be the down wind machine that finally makes LA fun.

Admin

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Re: Cowboy Foil Experiment Thread
« Reply #9 on: March 14, 2017, 09:36:55 AM »
Hi Cowboy,

Will you use bodyboard fins? 

surfcowboy

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Re: Cowboy Foil Experiment Thread
« Reply #10 on: March 14, 2017, 03:08:40 PM »
Admin... Try and stop me from using fins! ;)

But seriously, I swim in the surf a good bit actually. When it's too big at a beach break for me to SUP or surf even I'll throw on fins and go play in the waves. I also have a couple of buddies who I bodysurf and bodyboard with at least once a month in the summer.

My testing protocol will be:

Drag/swim that thing just outside.

Point it straight in.

Kick like hell.

Hang on and explore fore/aft balance which mostly means trying not to go over the bars and having to make use of my helmet.

I might try to take a bolt on fuselage and tail to see if that changes anything (Hey, while I'm out and wearing a helmet kooking it up anyway might as well gather some data.)

Then I'll probably grab a longboard and try to salvage some of my dignity at my local break before I roll out my next project...

Desert Camo Surf Mat! (Yeah, I'm starting one of those too, waiting on my glue to get here.)

I'm a late bloomer, I have to make up for lost time by surfing literally anything. If I make it to Maui this summer I might even get on a surfski with Headmount. I've clearly lost my mind.

Admin

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Re: Cowboy Foil Experiment Thread
« Reply #11 on: March 14, 2017, 03:41:01 PM »
Hah! 

You have an impressive start there. 

I was asking about the fins because it seems like the tops of the fins would/could still have water contact when foiling at that height and would act as your trim controls. 

surfcowboy

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Re: Cowboy Foil Experiment Thread
« Reply #12 on: March 14, 2017, 06:10:39 PM »
Oh, you mean like fins on the board. I hadn't thought of that. Good call.

I will say that I'm not sure my brackets will hold (that's tonight's project) so I might add a central flat piece of something to hold the foil at the flat AOA. If I do that, it and the 2 brackets should be pretty strong "fins" to keep it running straight.

I think turning this beast may be impossible but that's ok, I just want to see if I can lift off and then I'll move to the next test. Hoping to have this thing in the water this weekend.

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Re: Cowboy Foil Experiment Thread
« Reply #13 on: March 15, 2017, 03:55:13 AM »
I was actually thinking about your (foot) fins and if/how those will factor when you are on the foil.  Looking at some of the early bodyboard foil images it looks like the fins are playing a pretty big role.




« Last Edit: March 15, 2017, 03:58:44 AM by Admin »

Bean

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Re: Cowboy Foil Experiment Thread
« Reply #14 on: March 15, 2017, 11:18:56 AM »
Hmm, maybe I can get into foiling after all! ;D ;D

 


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