Making A Boat That Flys - The Hydrofoil

My dinghy was boring, so I 3D printed a hydrofoil for it! Watch how that turned out...
If you have enjoyed this project feel free to subscribe for more engineering antics in the future!
Thank you for your support.

[@TomStantonEngineering]

Epic project mate! I had great fun watching your build from the sidelines (aka our 3am fibre glassing session) and look forward to the next project!!

[@SamBarker]

Thanks for all your help, especially during the 3am build session!

[@struanrobertson4201]

@@SamBarker i thought you would need a longer engine shaft I love your videos to Tom i have watched them for a while

[@HispAnakin42]

Sam doesn’t plan nearly as well as you haha

[@PhatheadWRX]

I thought I recognized that voice about measuring zero times and printing twice 😁

[@NielsNL68]

I was sure you two where brothers, until i realized that you two had different last names. Your faces look so much alike.

[@0xhexdec]

Very nice project indeed! Hope to see a next version of your design. As I build Hydrofoils myself (for kitesurfing mainly), here are some quick tips: The analogy with the stool with three legs isn't the best here, because the amount of struts/masts into the water is absolutely irrelevant for the foil to work. The principle is simple: its just a plane under water. The front wing produces lift to lift you out of the water while the rear wing produces downforce to compensate the "wheelie". The faster you go, the more lift the frontwing produces. As your foil has no elevators, the rearwing produces the needed downforce to keep the nose of the boat down, resulting in much less wheight adjustment that must be performed. This is the principle of kite/surf foils. For a boat, where your main focus is the ease of use and not so much the performance, a Fontwing in form of a V would be the best solution (extreme dihedral). The faster you get, the more the foil gets out of the water and isn't capable of producing lift (sadly, the so loved self stabilizing characteristic you get in planes with dihedral wings is almost neglectable due to the high center of gravity). With the dihedral frontwing, you can easyliy achieve solid results without a rear wing and without a long-shaft outboard. Just mount the foil further to the front (the position of your first approach seemed about right for that). The last tip: The Angle of attack is way more important than the profile. Even a flat surface will fly well. In water a thick profile will give you a lower lifting speed but drag of the wing induced by a bad designed profile will kill your topspeed and, much worse, the lift becomes enomous making ventilations more likely and the boat uncontrollable. Hope this wall of text helps a little for your next revision, subscribed :-*

[@alejocouderc4495]

Talk about back seat building Jk of course

[@themobile6845]

Very well explained! Thanks 👍

[@slakjawnotsayin5451]

@@alejocouderc4495 LOL

[@slakjawnotsayin5451]

That was very interesting, thank you for the explanation and details.

[@Kuiper39]

We need a bigger one! Use a polyester boat as base, and make a jack plate for the outboard so you can lower it :)

[@junatah5903]

Honestly suprised by the subscriber count, was expecting at least 10k.

[@cavemann_]

They are just getting started, can't wait for more vids!

[@marsupialdungbucket]

My dad made a dinghy with a hydrofoil (as a prototype before making a 60-seater hydrofoil boat) back in the 1960's and took me out as a kid on it in Dartmouth harbour. I can still remember the moment when he put the foils (one on each side) down. We were going full speed already, but the acceleration at that moment was amazing! Doubled the speed in a couple of seconds and I suddenly understood what he had been telling me about how they worked. Sadly his business could never compete with the government-funded hovercraft industry, despite hydrofoils being so much more efficient (and comfortable) for routes like the cross-Channel ferry.

[@GoldenCroc]

Fun project. Hydrofoils are cool, but sometimes its hard to make them work, and depending on what boat they are mounted to, might be of questional benefit, if any at all. But it sure is fun building! One small correction: the effect you described is called "ventilation", not cavitation. An easy mistake to make, especially since the anti-ventilation plate mounted just above the prop on outboards is erroneously called "anti cavitation plate" in common parlance. But cavitation is a quite different phenomenon. Cheers.

[@SamBarker]

Hi There Golden Croc, yes thanks for clarifying that. Spot on, it was ventilation I was describing. Like you say I believe this project itself is more on the fun side rather than improving the boat. Glad you enjoyed the video. Thanks Sam.

[@brandonloukota4760]

Can’t wait to see where your channel goes, this will give us something to watch while waiting for Tom to post another video :)

[@chedatomasz]

From what I've heard you need to design the foils precisely so theyre stable and don't oscillate. Great attempt though!

[@Bombskwad92]

I can't believe there's only 5k subs here... so this is what its like getting somewhere early.. 👌 250k+ this time next year?

[@diogogermano7899]

The right term is ventilation becouse cavitation is a vacuum bubble and ventilation is a ar bubble Nice vídeo 👌

[@GoldenCroc]

Right you are. On some boats one might even purposely induce ventilation to make the propeller work in a more suitable rpm range.

[@SamBarker]

Hi Diogo, thank you very much for clarifying that. Glad you enjoyed the video. Sam

[@WayneTheBoatGuy]

This was brilliant. You covered all of the bases of whether this could theoretically work! Well done.

[@jaaaake777]

Fun project! Get a copy of Ray Vellinga's Hydrofoils (Design, build, fly) book and try to understand it. Balancing pitch and roll stability to make a small hydrofoiling boat that will stay on its foils is quite difficult. Making your dinghy achieve manned flight (with a suitable engine, wings and prop) would actually be easier in some ways. Hydrofoils have all the lift vs. drag mathematics that aircraft have, but a few more because they have to also deal with the interactions between water and air at the surface and a big change of centre of gravity and stability when they take off. They also need turn stability if you want them to stay on foil when they reach a bend. The first foil you made was far too thick! If it was to get on foil, a foil that thick would be inefficient and therefore make the boat slower than with no foil at all. I built a hydrofoil when I was 15 (I'm now 47!). It worked a fair bit better than this, but I didn't have true pitch stability either. It was a series of multiple stalls like yours, just slightly longer ones. I had an angle of attack adjustment system for the front foils, but it was so hard to keep it flying for more than about 50ft at a time. I had beginners luck with mine, because since I have made a series of failed hydrofoils. I have learnt that, sadly, to make an effective working hydrofoil you need at least as much maths as you would need to design, from scratch, a working full sized aircraft. Hydrofoils are killers psychologically, because any kind of foil that creates lift, which anything vaguely foil shaped will provide, will enable a boat to lift and porpoise and stall and repeat. This makes the builder think that they are 'nearly there' with it, which they are not. There are rather a lot of 'nearly there' porpoising hydrofoils on youtube.

[@chelseaandrews3967]

I genuinely really enjoyed watching that! Brilliant video! Looking forward to the next one!

[@jakefromstatefarm9721]

Free = 3. You’re welcome.

[@jacksbackable]

I’ve been going to play around with this myself, except with a rigid bottom inflatable. I’m impressed they didn’t blow off earlier on! I’m an outboard mechanic by trade, so different motors, not so much of a challenge. I also have the advantage of living in a country with better Weather. You’ve given me a couple of different thoughts now.🤔💭 Thanks for sharing. 😎🏖🌴☀️🇦🇺

[@stephensidaras7416]

Ventilation not cavitation.

[@fluiditynz]

I've been wingfoiling and designing my own hydrofoils for a couple of years now. That front foil looked very thick to me. On the personal hydrofoils, weight placement on the foil board is absolutely critical. Also surfaces. The difference between a poorly finished surface and a 400 grit to 1000 grit finished surface with no imperfections is phenomenal. I 3D print my wings in sections with holes for joining dowels, fit them together and then spend a few days cleaning up the surface. Then I create moulds around them using parting tape and resin infusion. Finally I clean up the moulds and for my higher performance wings I make now, I fill them with carbon fibre, mostly unidirectional. Then I clamp my moulds together. Unmoulding, I clean up the excess with a mini angle grinder, then file and sandpaper in progressive finenesses. If you continue, you need to make a decision as to whether you are using self flattening foil designs for roll and how you will control pitch stability. And of course under an IRB, you will need a lot bigger foot glued or otherwise fastened to handle the forces. I really was surprised that the attachment you used lasted as long as it did.

[@PabloDiabloable]

Very interested in what kind of glue you used to glue the foil to the boat? This may come in handy for projects I have. Thanks!

[@marshallwilliams4054]

Would love to see a follow up video to this. Why not try a dual plane set up? Also, I wonder if greater distance between the two foils would provide for a better balance

[@chrisschaefer3863]

They make long extension motors, often used for sail boats. this might keep the prop deeper.

[@shrippie-4214]

This guy is basically a better william osman xD

[@PeakTorque]

Subbed! Great stuff.

[@tench745]

Small point of note: Ventilation is when the prop sucks in air. Cavitation is when the prop is spinning faster than the water can move in around the blades and tiny pockets of vacuum form against the prop.

[@InventingThings]

I absolutely love this! I would have never considered just using fibreglass to make a part stronger thus you can utilize it in a practical application :0 Fantastic job

[@watahyahknow]

seen a hydrofoil modelboat made a long time ago , the builder made them out of aluminium bar that he shaped intoo a wing contour (though sharp in the front and sharp in the back ) painted the wings after he finished and tested the model and all of a sudden it didnt perform like it was before it was painted after a while he saw flakes of paint comming off the aluminium wings and doing some speed runs passed his boat he found loong bubbles comming off the wings under the water turns out those foils need to be supersmooth or they cavitate on there own and loose efficiency you probably need a longer tail for the outboard to keep the prop in the water when its on the foils to get it a little more stable you probably need to make one set wider then the other , since most of the weight (motor and driver) is on the rear i would make the rearwing a little wider might want to see baout being able to adjust the angles on the first prototypes to get the boat to come out of the water evenly

[@chrisoates777]

Awesome buddy..... I'm just letting you know we need to 3D print a full sized Iron Man working suit, so I can carry the kids to school in it....... might need more than one video. Well done Dave v2...

[@DorsetSaferRoads]

I think you needed less area on the flat section and a shallower V as that's your height control, as you go faster the V Comes out the water so it produces less lift. Go faster, more lift, more of the V Comes out the water until it reaches a equilibrium.

[@ThegreatNomadicadventure]

Great video look forward to seeing this channel sky rocket 🚀

[@bry29bry]

Great video and project!

[@dherrendoerfer]

I don't think this was really foiling - it was more or less skidding on water like a waterski. You 'd probably want a V-shaped foil that produces lift, but where the lift is reduced the farther it comes out of the water. A foil board (like shown on the video) actually requires the person to level out the board to keep the foil in the water and not stall out when coming out of it. Same with the foiling sail boat. It was impressive though, never would have thought the small outboard would lift it to the point of stalling.

[@ketchfarcaster]

If it flies, floats or, um, "freedee" prints, better to rent it...

[@IteKLF]

Totally something I have wanted to do for YEARS! FINALLY someone did it. But, please use Naca airfoils and loft. And also, you should think about making it self stabilizing.

[@paxwallacejazz]

GEV ground effect is the fastest safest most efficient way to travel across water. Can be under around 60 hp. Motorcycle or auto or aircraft engine

[@captainKedger]

inflatable dinghy is relatively heavy for what you're doing. I'm planning a similar project using a small lightweight trimaran hull and a jet drive. The idea is to have an intake under the bottom of the front foil and twin output nozzles under the back foil. The pump driven system will prime itself when it's sitting low in the water. Steerage will be done with both output nozzles using 360° rotating nozzles so it will have reverse and side thrust. The jet pumps will be powered by steam and the steam will be generated by a hybrid solar and alcohol boiler. The idea is to run it on sunlight during the day and alcohol or any volatile fluids I can scrounge or make at night. There's a conservation area near me where fossil fuel boats aren't allowed and I want to go speeding into it on a hydrofoil and get stopped by marine patrol so I can tell him that I'm not breaking the law but he is for following me into the area. 😂

[@forrestberg591]

Subscribed so I can comment I was in your first 10 when you’re a big engineering tuber in a year

[@maxper75]

Nice video, this confirmed me the doubts I was having about building such a project myself with much more limited skills and tools... Nice work!

[@murraymadness4674]

You just need a bigger motor, and really why 3d print, use foam and fiberglass and be done in a couple hours. Of course you are just making click-bait videos for entertainment, so just ignore my comment, I'm sure it will help with the algorithem.

[@Flash-Strike]

Great IDEA brother LOVED! New subscriber 3D print always a Bad-Short-Cut ...(?)... well old ways are my way .. anyway .. GOD Bless you and yours

[@mm74forums7]

Interesting idea! However the profile of HF is suboptimal from my perspective. Too thick. That is why it has too much lift and lots of resistance. You can estimate a profile according to a mass and speed in XFLR5 program (free). Also you can just look at wind/wing-foiling or Flying Moth hydrofoils, what profiles do they have. Rear wing (stabilizator) should be smaller and have symmetric section profile, It should be regulated to produce neutral and negative lift for stability. Also you should sit at centerline of the boat. HFs are quite sensitive to roll. Good luck!

[@muzelmuzel5786]

you need POWER! I have a similar boat, it required 7.5 hp to get in plane with 1 person, (would not plane with 2 persons) also tried with a 6hp motor, it would not plane. when 6hp boat towed by another identical boat with 7.5 hp, we got both in plane. but the 6 hp would slowly loose speed when i dropped the towing rope. i would suggest 9.9hp minimum, and try again . awesome video!

[@ZeptZmarz]

A freedee flyin’ boat

[@nedwelch1217]

Awesome proof of concept! But I dont understand why you added a second foil, when your first test showed your first foul providing ample lift. If an airplane noses up, you don't add a second wing, you move the wing backwards to put the Center of lift below the Center of mass!!! Your second foil is just adding drag. Seems like you're also setting yourself up for problems by positioning yourself on the gunwale. Good for skippering a floating dinghy, but awkward if you want to balance above a foil. Easy to correct, though! Extend your outboard's throttle handle with a short piece of pvc pipe that fits snugly over it. Now you can helm your dinghy from the Center of the craft -- even from a standing position, if your pvc pipe is Ing enough. Will make it MUCH easier to shift your weight around to balance. Suggestions aside, congrats on the very cool build.

[@richard--s]

You could export your gcode 3D print files with higher accuracy to get smooth looking bent shapes, not those edges on the bent surfaces ;-) It takes the same time to print it, it just looks way better. When it looks like there are edges in it on the slicer object placement view, you get edges in the printed object of course ;-) 2:25 and 2:29 8h wait, 4:57... And the fiberglassing before... OK, but still ;-)

[@GeorgeOu]

You'd be better off just buying an off-the-shelf foiling wing from those foil boards. Make that work first, then try to make your own wings.

[@letmefindout81]

Thumbs up for him , he is doing fiberglass in his kitchen. Fiberglass resin stinks and it won't go away

[@sebastianmichaelrogel6404]

That's not what cavitation is. Cavitation occurs, when parts moving through water sufficiently reduce the pressure to evaporate the water. Those gas bubbles quickly collapse as soon as pressure renormalizes forming ultra fast jets that can pretty much destroy anything.

[@K_Nasty]

4 stools and that boat have 4 "legs " dude you have got to be the worst "engineer" ive seen. Printing for a day ... Backwards ...wtf man

[@markandrews6054]

You're foilin' bonkers mate. OK if truth be told I've been playing with the same idea for the past 3 years, albeit I don't intend to make a prat of myself on my own KZbin channel. I'll just appear on others LOL.

[@K1VV1939]

Remember what you said about 3 legs? Look at doing that again but this time Remember what you said about 3 legs and Because there's no cavitation from the front the foil the motor will not suffer cavitation. Thing is Sam you had it !! build the bridge of the 2 front foils over the top and the boat hanging off the foils. 2 out the side foils will provide stability like I swear you needed to go for a swim behind that boat till your foils fell off. Yes Sam total failure because you can't count to 3 please try this again and here's a tip. Run a compressed air feed to small holes about 10mm apart and a 3mm dip along the leading edge of your foil - when you want to go faster turn the air on. The foil will then fly into an air bubble and it doesn't take much to make a foil actually fly in air under water. And again it doesn't cause cavitation because cavitation is made with big bubbles and you're controlling the size with 1.5mm air jet holes and a pressure reg. Your foils are not proportionate do some research on foils and notify me when you start your next build.

[@experimentalcyborg]

Hydrofoil airboat? Basically an aeroplane with its wings submerged. Or mounting (electric?) propellers on the rear hydrofoil, so they're guaranteed to be underwater.

[@Devo491]

You would have done better to use a light-weight dinghy. I have an 8-ft aluminium dinghy I can carry on my shoulde, I'll have a shot at this. Hope my 4HP motor is up to it...

[@joachimkarstens9769]

holy fuck, you are fiberglassing without any mask and inside?? 10inches below your nose? hoooly crap. At least you shouldn´t inspire others to to that!

[@shoutatthesky]

Say after me, TH-Ree. There is no F in three. It's not a "free D printer", It's a THREE D Printer! Also, it's THen not "Ven", and THis, not "viss"

[@ojivlogs]

the back is too heavy and the prop is lower then the boat which cause a rotational force (like a back wheels of a car doing a wheelie), you need to put the wing much closer to the engine but generally this boat is just too light and unstable for this

[@Drunken_Hamster]

>2HP You need bout 15 to be truly effective. But at least a 9.9 would've- Well, I stand corrected. Huh.

[@juggernautz]

Nice try so back the drawing board. To prevent ventilation you may need a long shaft motor or find a way to lower the motor mounts. Who makes the shirt you're wearing, I like the block pattern ?

[@jeaubeau]

Watch a couple of Johnny Quest cartoons from the '60s . Johnny's dad had some great hydrofoil boats from back then check out the design of these cartoon boats. Great stuff. 👍

[@juststeve7665]

a little bit of research into Hydrofoils would have solved your problems before you ever had them. Perfected technology in the 1960's.

[@olsonspeed]

Success? Your definition may vary.

[@davidt1621]

Just so ya know, carbon fiber fabric isn't as expensive as it once was. You can get it fairly cheaply, as well as carbon fiber rods online. Just get a bit of thin cardboard and glue several sheets of carbon fiber fabric to either side of it and you can trace and cut out any pattern your heart desires. Best part is, you don't have to wait days for it to be printed, and it's a lot more durable than any plastic. Also, is that your old motor sitting out in the rain at 9:10 😅

[@jondierksheide6883]

boat motors are designed so the prop in underwater a certain depth. If you raise the boat (and motor) out of the water, it doesn't work. you need an extended shaft outboard that puts prop deeper in the water. Also water is much more dense than air, so you need a hrdro foil not an airfoil. There were plans and instructions in about a 1960 popular mechanics or science that showed how to build one with a foam slab hull. My dad always wanted to build one.

[@fiona-hh2hu]

Hey, I'm struggling to cut a large print like yours into pieces. Did you do it in Cura? I get error messages when I use the mesh tools. Please help!

[@Derakday]

your Hydrofoil fins is too big too straight wide and created too much turbulent make it very unstable to canceling the thrust, you may try to use the delta fins (could be more than one) to maximize the fin surface force to create the stable upward force to counteract the gravity and push to boat forward.

[@terrycollins3954]

The hydrofoils would be better if they weren’t in a fixed position Mmmmmmmm you should try to adjust the blades of the hydrofoils according to your speed

[@Zomby_Woof]

On the whole, it was an abysmal failure. But the video has value as an example of easily avoidable mistake and ill conceived design strategies.

[@warrenharper8524]

Nice one pal plan bodge should work just fine. Had me laughing

[@user-wangyu]

I will test on aluminum boat this summer my imagination， put smaller foil to the back half or back to center of mass

[@aceofwaters]

obivously if the engine is mounted on a transom at the ideal performance height, if you lift up, the prop will be too high/out of the water. 1st thing I said when you went for this project, you need a long long shaft engine.

[@Luuxs]

you need a bigger 15hp 2 stroke engine with a long tail, the back side foil also needs to be the same as the front one because else there wil be only drag no lift.... look up "russian hydrofoil boat"

[@letmefindout81]

Looks like you might have to angle it up maybe. Next video please

[@ProjectHub1]

great video! bro the quality is great insane for such a samll youtube chanell.

[@ysesq]

the prop was ventilating not cavitating. you can avoid with dole fins.

[@dax6604]

My dream is so figure out how to make a hydrofoil mini jet boat in my mind idk if it will actually work but in my mind my hope is that it will be able to withstand much rougher waters making it more versatile and efficient

[@panzerfaust480]

Under powered engine is your issue. Inflatable boats can plain very well, just as long as the engine is strong enough and there is enough weight in the bow.

[@3DLasers]

Rule #1: Measure once, cut twice and pound to fit... Rule #2: Never forget Rule #1

[@mozkitolife5437]

You're like a dizygotic twin of Tom but didn't get the recessive ginger phenotype.

[@thankyouforyourcompliance7386]

Nice Projecr. We need more foilboats! But pls get rid of these annoying IC engines and get some silent electric ones.

[@Diesr]

Cavitation is water turning into steam while a prop is spinning very fast and makes a vacume and then pops that pop is cavitation you where just breaking the surfaces of the water with the negative pressure that sucked air into your prop not cavitation

[@aidennymes6335]

outboard sucking air from the surface to the propeller is called ventilation. cavitation is empty air pocets created on the propeller under water through low pressure. great video hope to see some more

[@fooman2108]

seing the dinghy with the foils on it upside down I was thinking what would happen at 100 KPH when the wings lifted the boat off the top of the car!

[@SimonAmazingClarke]

Foils were far to thick and, as you found out, a bit of glue was no where near enough to hold them. Next time use a gauge on the roap from the boat to measure drag.

[@westmonroe-r1v]

A guy did this on a sun burst sailing dinghy in NZ he only had a 4hp seagull he pushed the outboard down on a bracket like you use on a trailer sailer.

[@AlbiesProductsOnline]

Why don’t they make 1 legged stools? because forgetting to turn they upright can be a big pain in the ass 😜

[@tshirtsnjeans]

The flute made your maiden voyage so epic!

[@pontoonrob7948]

I think your foils need to go outboard there by keeping turbulence away from a longer shaft outboard

[@cyberhatter]

Great design. Patent it before it gets snagged. I'd pay $$$$ for a bolt on kit for an RIB.

[@spock81]

@rctestflight hydrofoil Boston Whaler when???

[@ПавелРолик]

Не хватило ширины крыльев, поэтому лодка на бок заваливается. Крылья надо делать шире

[@UncleBildo]

I'm thinking a 3 leg, with jetski engines in the front two.......

[@ZachsGarage1]

6:26 Hard not to put a smile on your face lol

[@milessmith7600]

I don’t know who needs to hear this. But hear me out. Planes can already drive on the water and take off from the water…

[@kinetic1259]

You can save hours and hours of reading and study by doing months of testing and prototyping 😅

[@nicksgarage8295]

can you share the files. i would like to make one for my boat too;.

[@sebastianlang1014]

What if you use masts and motors of electric Hydrofoils?

so summer is now one and a half days a year in Britain? Climate change does turn out nice for you chaps!

[@bikerguykrash1182]

Why not 3d print a water jet thruster that draws in through the front or sides of the foil and squirt it out through the back?

[@richardowen783]

I used to hydroplane our little dingy, get a slightly bigger motor, we had a 8hp and seat on the front seat

[@paxwallacejazz]

Stern foil with lower engine mount

[@MasterYota1]

Linked over from your buddy. Watching ..

[@DktheWelder]

Well done ! I have a small boat that I put a long tail motor on so the height won’t matter I have an ender 3 printer would like to print some hydrofoils. Would you be interested in sending some of your drawings from fusion 360? Your ones wouldn’t work for me but would give me a good idea of the profile