Author Topic: Cowboy Foil Experiment Thread  (Read 28385 times)

surfcowboy

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Re: Cowboy Foil Experiment Thread
« Reply #240 on: August 05, 2018, 11:08:33 PM »
Ok, so Iíve been pecking away at this a bit. Going to post some catch up pics of the failure. Notice the ratio of wood to carbon. Major source of weakness.

After that, you see me mocking up a cardboard piece to cut my plywood pieces. Then gluing up my new front piece and finally a shot of it glued into the cut out area of the mast. Iíll carbon the hell out of it, likely 10-12 layers. And then adapt the wing to match it. From now on, the wings will have a flat spot on top to mount up to the wing, or, thereís a chance I might attempt to wax up the front and make a receiving pocket on the wing. Depends on how Iím feeling when this mast is all layered up.

Even got some time in Fusion360 working on new wing design. Who am I?

opie

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Re: Cowboy Foil Experiment Thread
« Reply #241 on: August 06, 2018, 01:48:48 PM »
That first photo really highlights how clean your wing came out.  Good luck!


surfcowboy

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Re: Cowboy Foil Experiment Thread
« Reply #242 on: August 06, 2018, 11:09:29 PM »
Thx man. Iíve started planning the big wing. Talked to my buddy with the 3D printer today and he can do up to 19Ē tall so I think we can do this in like 3 pieces with the wings mostly one piece which is cool.

surfcowboy

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Re: Cowboy Foil Experiment Thread
« Reply #243 on: September 09, 2018, 08:27:42 PM »
Ok, time to mount things up again. Need to check my angle here. Much discussion about angle of the foil.

The last time, I set it to be level according to the chord line, meaning the line drawn from the fron tip of the foil to the trailing edge. This puts the bottom of the foil angled slightly downward, meaning the leading edge of the bottom of the foil is lower than the trailing edge.

Just checking here. Should the bottom be flat or angled up? Or is my neutral point along the chord?

Iím hearing that I should have 1-3į of positive angle but not sure where to base this on.

Should be able to get this thing mounted again before long but want to make sure Iím not doing this wrong. Whatís up foil builders? Flat bottom or what?

kiwi

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Re: Cowboy Foil Experiment Thread
« Reply #244 on: September 09, 2018, 08:42:12 PM »
Im pretty sure AOA is based on chord line and not the bottom surface of the foil.

The tool in this video is creating a surface parallel to the chord to measure AOA off.

surfcowboy

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Re: Cowboy Foil Experiment Thread
« Reply #245 on: September 09, 2018, 09:20:50 PM »
Thx, Iím pretty sure back months ago in this thread that was answered lol.

Iíve been on this so long itís become comical but I resupplied this weekend and have my new mount design so Iím off and running again.

Also ran into ďPacificmeisterĒ of YouTube efoil fame out at County and he was super encouraging which is often all you need when you are deep in a project.

He also cautioned me about yaw stability with flat wings so I may be adding a little tail stabilization once I test this thing. We will see. My fuselage is not round so Iím wondering if that may act as a bit of a rudder as well.

surfcowboy

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Re: Cowboy Foil Experiment Thread
« Reply #246 on: November 06, 2018, 08:34:35 PM »
Ok so itís back to a solid piece. Take a look at my idea for V2 here.

The idea is to bolt from below the wing into inserts in the bottom of the fuselage to mount the wing. The bulb on the front of the fuselage is 2 3/8Ē (60mm) wide. Wondering if that will be enough leverage to hold it on. The new Neil Pryde are narrower than that but I could put a plate on it or extend the base just a little with carbon but am really trying to get this wrapped up. Thoughts anyone?

The fuse will have 4 bolts. 2 on either side of the bulb and then 2 further back in a line towards the mast. 4 x 6mm bolts into inserts in the wood and carbon core to hold things in.

Otherwise I think Iím going to follow Kiwi and Containerís lead and start another wing out of plywood to make the prototype quick. Really want a 36Ē wide wing with some anhedral. Probably make another tail wing too.

One thing is for certain, it will not break at the same place as last time lol. I think the fuse is solid, now just need to make sure my wing can take the strain. Carbon is my friend there until I get a plywood one prototyped up.

Here goes, what do you think of my repair? Just got the hot coat on it last night. More pics to follow.


« Last Edit: November 06, 2018, 08:38:56 PM by surfcowboy »

kiwi

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Re: Cowboy Foil Experiment Thread
« Reply #247 on: November 06, 2018, 11:37:02 PM »
That looks heaps better scb

I think the only reason the fuz wing join on naish and neilpryde can afford to be so small is of how they are molded and basically locked together
My first wing join was 60mm wide and it worked plenty good for a bit until I really started to turn it but it was probably a combination of things really.
with that amount of carbon it should fly sweet as