Some interesting information in those posts..
Stablility is the resistance to manoeuvre
I'm running a 0/0 setup at present with a symmetrical rear foil.
I'll let you know how it goes !
This guy is a foil making machine!!!!!!!!
Check out his effort ! Moulds, Cad, Resin infusion system !!!!!!!!
That video is off the charts - respect! Excellent to see so many different approaches to home-builds. Just be careful with those chemicals - epoxy sensitisation is no laughing matter. And please keep the info flowing on any resins you discover with reduced toxicity and environmental cost.
Here are my tips:
No matter which epoxy you use, the thinner the epoxy layer, the stronger the bond.
Ie - even if you are gluing two surfaces together, there is a monumental difference between the strength of say a clamp holding the two parts together, or say putting the whole thing in a vaccum bag, which if it's a large part ( 100 square inch ) - could be the same as 1000 pounds of weight holding it together. The difference afterwards, I would guess up to 10 times stronger bond - I delaminated the first piece by hand strength, the second piece, the actual part started to fail while the glued area held together.
I use MaxBond structural - simply because they ship to me, and there is no local glassing shops, they have a massive range.
If your trying to fill a small gap with the epoxy - you have to use some kind of filler to add to the epoxy ( you don't necessarily need to change to another epoxy ) , and my theory is, the size of the gap, is the size of the particles that you should use - so if you have a 4 mm gap, then cut 4mm off some fiberglass or carbon weave, mix it in to the epoxy, and you will have massively better results again, because epoxy by itself is brittle, and that is why it fails - mix in some carbon or glass.... I think another term for it is adding "FLOX"
Thanks Plummet. Excellent info. I got my rough drawings now. Let's get started on the measurements!!
That is also what I am designing. I hope it works. I will make my foils but not attach the rear one so I can still flip it around the other way if it doesn't work. Please send some feedback as to how yours rides.
Well the neutral one goes ok,
basically - If you wanted it perfectly balanced, you should be able to go with 0 degrees AoA on both foils, and move the rear one aft.
I used a symmetrical rear foil on both mine, they both work, and are very manoeuvrable, but I had to move my mast forwards quite a long way
I'm about to change to a lift foil pointed inverted on the rear stab, and I believe I will need to shift my mast back a little again to compensate.
I've also got a production freride and race foil to test out, but atleast I can get some back to back in a week or two
Got a few hours work into my foil this weekend. Also made some progress on my directional DIY board. Will post some pics when my foil is done. I went 64cm by 14cm. Very slight anhedral.
Select to expand quotedachopper said..
The carbon print looks stiffer than pla, but in the big scheme, unless I was targeting a race or speed foil, it's not really needed. All the stiffness comes from the fiber orientation on the outside,
I was more getting at not needing the external layup of carbon, because the whole thing would already be full of carbon fibres.
I don't know how strong it would be though. I haven't tried it yet. Also you need a stainless nozzle, otherwise it rips your brass one a new -hole pretty quickly.
I did some research, the carbon in the glue is tiny length, so u would need outside finish, but there is a new printer in the works that prints, then lays down a complete 3k strand of carbon or Kevlar, that would work, but the print volume is not large enough to fit a foil :(
great video and really good product for backyard build,
Pre-preg carbon would add a heap more strength, didnt quite see the laminate schedule but Uni's in both the horizontal and vertical would be a 100% requirement for me.
i dont really like the Ti, or SS rod as a carbon rod would be as strong or stronger,
but this is being super critical as im working with some insane boat builders currently and the most state of the art boat building techniques on the planet.
great to see so many guys building their own foils, from my foiling experience the biggest thing is stiffness of the mast, or vertical. this cannot be stiff enough. dont be super critical on weight, stiffness is a hell of alot more important than weight(to a point) so another layer or 2 on the vertical is better than a weak section.
just my 2 cents worth
Just fitted a new front wing, still learning but this has improved the foil heaps. Very controllable and stable, the wing is parallel keaping a similar lift across the foil.
The first wing tappered at the tips and worked fine but much harder to fly and control. Now I'm able to start carving the board rather than concentrating on just keeping it flying.
I'm sure over time mk3 and mk4 will eventuate as the learning curve continues, happy foil building.
I'm ready for a test flight. Got clear coating and painting to go. But that can wait until after my kiting trip next week wind is calling.
Select to expand quoteHardcarve1 said..
Is that a flame or Hammerhead shark on the mast ?
Why yes it is!
Select to expand quotePlummet said...
I'm ready for a test flight. Got clear coating and painting to go. But that can wait until after my kiting trip next week wind is calling.
Looks very tidy Plummet ! Not sure about the benefits of clear coating it - The first thing we all do is sand ours immediately from new to get rid of the shine. Glossy foils seem to cavitate a lot and ride like sh**. The fastest finish seeems to be a good sand with 400 wet and dry - nothing too fine.
Everybody's projects looking good! Busy shaping the rear foil. Already attached front wing. WIll post pics soon.
Here are some pics of my progress. Next i need to shape my mast and attach
What you guys think?
Good ride today on my indestructible foil, I figure top speed is pretty low, like 15 kts, but it still cranks upwind and is super manoeuvre able at low speeds,
Anyhow, here is the high aspect foil cleaned up a little, awaiting me to make the other half. Trialed an alternate way to lay the carbon and it worked big time, just need one more tweak and we should be able to get razor sharp leading and trailing edges ;)
Any engineers in here geeky with CNC machine design?
