Diy sup foil

[supuk]

the crash was on a fairly steep wave, I think the problem is having something that will lift at slow speeds but then that does not produce to much when you hit a big drop.

[supuk]

Again  I havnt had much time to play with this but I have done a few modifications, I have added another few layers each side of uni carbon up the mast to stiffen it up more and have allso made a new thicker front foil. Now with more pictures coming out of the go foil you can see just how thick they have gone.

[TallDude]

That was not a good direction or position to fall with that foil in your landing path .... closer than you want.

[supuk]

I have Been thinking about this a little more recently and ways to do faster lighter and more accurate prototypes and after doing a bit of looking around on the net and getting a little inspiration from seeing rc planes being 3D printed i think 3D printing some cores to then vacuum bag could be a good sollution  the only thing is I'm rubbish on cad and don't have a 3d printer yet.  I have said to myself I'm not allowed to buy a printer until i can use a cad program properly so that is going to be my first step while I'm in Australia over the winter. It will alls mean that ideas and designs could get shared around quite easily which should be good for development. 

[supuk]

this was the video that got me thinking

https://youtu.be/4ybuv2TEYrk

[supuk]

Not much good for 3d printing but I thought I would have a play on Shape3D at drawing a basic foil similar to that of the go foil ie with a nice lot of volume inside, I could also cut one out of foam no I suppose to see what it comes out like. If any one else would like the shape3d foil to do a little refining to im happy to share the basic drawing to get you started.

[surfcowboy]

Yeah a 3D print would be a great way to control the variables too.

[capobeachboy]

Am I crazy to think that a model airplane or glider wing from foam would work? Glass it up and go? I'm pretty sure that'd be the fastest way to play around.

I picked up one at Walmart awhile back with this in mind but didn't have the time to get around to it. I'd rather let the pros do the R&D and pick up their cast offs.

[supuk]

In principal if you could get the size about right you may not be far off.

[supuk]

so I'm slowly learning to draw in fushion360 so I can cut some moulds to build my next foil its a slow process but getting there and should make life easer in the future. Does any one else use fushion on here?

[surfcowboy]

I have a buddy who was learning it.

One note on the printer, I'd offer that paying for a print of that size might be better since most of the cheaper ones are small. I think your foam idea is right on.

I've been considering looking at getting a mast cut out of plywood with a CNC. The idea being that a mast made of two hollowed out plywood pieces glued together and covered in carbon might get us there as far as stiffness, strength and lightness.

Though your mold looks good too. What would you want that made of, would it be printed or CNC?

Seems like the foam for a wing could get you there with the right carbon layup.

Let's try to crowd source a design here. Even if we all pitch in most (none?) of us would commercialize it and you could make them to sell if you wanted. Open Source software has worked like this forever. Use it for free to make your own solution or pay someone to do it for you if you don't have diy skills or want support.

[supuk]

I'm going to cnc the moulds, they can be cut from a number of things anything from plywood or mdf to aluminium, they all have there benefits but odiously cost varies.

cncing ply wood and then covering would work but then you mat as well cnc the mold and do away with having to do any surface finishing on the part.

soon as I can figure how to do this fillet I should be good to go with running a test on the mast and then will try and design the rest. It would be great to get some numbers of a original foil to work from. I'm still waiting for my reply from go foil on my order.

[PonoBill]

Broaching in a bigger wave is going to be an issue. Most of the foil surfers I see get out in front of the wave and ride the rising swell instead of a critical pocket. A foil that lifts at a bit over paddling speed (5mph) is going to have a substantial foil coefficient unless it has a lot of area. That high coefficient foil is going to be very draggy, and it's going to be speed sensitive.  If it lifts 200 pounds at 5mph it will lift 288 at 6 mph.

The higher the speed you get the lift you need, the more range you have. If a foil lifts 200 pounds at 7 mph it will lift 254 at 8mph.

Making a foil from an RC plane wing is pretty easy. If you can find out what the foil coefficient is of the wing it's fairly easy to calculate how big it needs to be for the weight you want to lift.

[supuk]

Broaching in a bigger wave is going to be an issue. Most of the foil surfers I see get out in front of the wave and ride the rising swell instead of a critical pocket. A foil that lifts at a bit over paddling speed (5mph) is going to have a substantial foil coefficient unless it has a lot of area. That high coefficient foil is going to be very draggy, and it's going to be speed sensitive.  If it lifts 200 pounds at 5mph it will lift 288 at 6 mph.

The higher the speed you get the lift you need, the more range you have. If a foil lifts 200 pounds at 7 mph it will lift 254 at 8mph.

Making a foil from an RC plane wing is pretty easy. If you can find out what the foil coefficient is of the wing it's fairly easy to calculate how big it needs to be for the weight you want to lift.

perhaps this is were the trimming wand that the moths have could be used.

I'm not relay one for doing math so most of my stuff is done on the 'that looks about right approach' then build test and refine. I'm happy to play with numbers if you can give me them. The one good thing about fusion is it plots 4 and 5 series naca foils so not to hard to try different sections.

The naish foil has the area and size stamped on it so gives a bit of a idea.

[PonoBill]

The wand and related angle of attack mechanism is pretty fussy and fragile. The pumping and pitch changes foil surfers do is to duplicate some of the function, partly changing angle of attack to vary lift momentarily, and partly adding some energy to accelerate.