R/C Hydrofoil with Sonar Pt.1 - Build

big thanks to squarespace for sponsoring this video recently i got the urge to build an actively stabilized hydrofoil boat so what exactly is that well hydrofoils are basically just wings flying underwater like airplanes they can be cleverly designed to have passive stability where the vessel has a natural tendency to want to keep itself upright this is usually done with surface piercing foils where the lifting surface penetrates the water the lifting force varies in relation to the depth the foil is submerged so as the boat tilts to one side the foil from that side becomes more submerged and therefore generates more lift which rights the boat in this incredible rc test flight video from 2011 you can see that i tried building one of these before it might actually have worked if it weren't so underpowered also quick tangent i thought this footage was lost forever but it was actually hiding in this video i had built a big reverse delta ground effect vehicle that's remarkably similar to the one i worked on for the flying ship company and this is way back in 2010 i remember it working on grass but it didn't have enough power to get off the water you could even see it from the google earth satellite view for a while pretty hilarious anyways let's get back on track the passively stabilized hydrofoil is not what i want to make why you might ask well passive hydrofoils are at mercy of rough water since the wave height will change the amount of lift the foil makes which then makes the boat go up and down with the waves not ideal i want to make a fully submerged foil that is shaped like an upside down t the benefit here is that they are immune to choppy water this is because the wing itself is always under water generating a consistent amount of lift regardless of the wave height as long as the waves are shorter than the height of the vertical portion the challenge with this design is that it does not have any natural stability so we need to actively control it to keep it from tipping over to do this i'm going to use a drone flight controller to measure the angle of the vessel the angle of attack of the hydrofoils will be controllable with servos so the flight controller should be able to stabilize it just like an airplane but enough with the theory let's start building this hydrofoil was the very first thing i made with my new stepcraft m1000 i cut the whole thing with a two millimeter end mill because my larger ones hadn't even arrived in the mail yet so that took quite a while i used tabs to hold it in the stock and cut those with a dremel then sanded it all down nice and smooth i only ended up cncing one of these hydrofoils and i wanted to try 3d printing the other two so that's what i did i was unsure of whether 3d printing would be accurate enough to maintain the precise airfoil shape but upon splitting one in half we can see that it looks pretty good i printed these in three parts and glued them together with some rods for alignment the major downside to 3d printing these is that they have little fdm ridges so i had to do a whole lot of sanding to get rid of those once they were fairly smooth i plugged the rectangular holes that were for the pivot piece with clay so that they would not get filled with resin when i fiberglassed them which is what i did next here we go mixing up some epoxy and painting it on the foil then covering the whole thing in a few layers of 2-ounce glass wetting the cloth with epoxy after each layer after the fiberglass came a layer of plastic film to keep the epoxy away from the breather cloth and the breather cloth helps smush everything together when the whole thing is placed in a vacuum bag and the air is pumped out which is what you see here i used my 3d printer bed as a curing oven and a few hours later i took everything out of the bag and peeled it apart the fiberglass turns clear when epoxy resin is added so after that i trimmed the edges with scissors and then sanded them down i cut away the fiberglass from the clay filled holes and picked the clay out then i sanded the fiberglass down nice and smooth here you can see the nice sharp trailing edges it's very important that hydrofoils are super smooth because water is 830 times more dense than air so any little impurities create a ton of drag next i cut some little tabs out a four millimeter carbon fiber plate on the step craft and epoxied those into the foils once again i cured them on my 3d printer bed i ended up doing another glaze of epoxy so i had to sand that down smooth too then came a layer of spray paint to finish things up and that just about does it for the foils themselves next it was time to build the vertical parts these are made from two 3d printed halves that i glued together you can see there's some little steel pins for alignment and here i'm pressing in the bronze bushings for the pivot mechanism once the glue dried i had to sand those down smooth and then i plugged the holes with clay next it was time for more epoxy and fiberglass i got all the layers of fiberglass together added some peel ply and then put it in the vacuum bag and back on the 3d printer bed and that's when tragedy struck i only had the temperature like 5 degrees c hotter than before but the pla melted i really never learned my lesson when it comes to melting 3d printed molds terrible when i would peel off the peel ply it would create triboluminescent x-rays which is pretty cool so after irradiating myself i then had to do the whole thing over again this time around i had some spare carbon toe laying there so i put it on the leading edge if you were wondering what the black stripe is so after doing the whole thing over again i finally had some usable parts so then i got to work cleaning them up and sanding them down i used a little end mill on my dremel to cut back the fiberglass over the pivot hole the trailing edge on these is super sharp for maximum hydrodynamicness i then cut some m3 shoulder bolts from the snow cap project to make these little pins for the pivot i then connected push rods and threaded them up through the vertical parts pop a pin in there and you have quantity one active hydrofoil pretty freaking awesome then i put a thinner rod on top of the push rod to interface with the servo and held it on with super glue and heat shrink next it was time to start on the pontoons i cnc cut these out of pink xps insulation foam on my m1000 this was a two-sided milling operation so you do one side and then flip it over to do the other i used little steel pins on the router bed to align the stock perfectly for the flip this is definitely the hardest part of milling two-sided things in hindsight these pontoons are the wrong shape but i'll talk more about that later after milling i cut the parts out and sanded the foam down smooth the raw foam is quite porous so i gave them a few layers of polycrylic then i inserted the hydrofoils into the floats and installed some high-tech hs 5086 waterproof surface to control the hydrofoil angle shouts outs to the guys at high tech for hooking me up with these fresh servos then i fired up my new flashforge adventure 4 3d printer and printed some of the parts that would be used for the turning mechanism for the rear float i assembled these with a square stick some bearings and some screws and it made a nice little pivot mechanism and then i glued that into the rear pontoon this is basically our rudder next i 3d printed a bunch more little stick joints and used them to assemble the whole thing together this is basically the chassis it's powered by a brushless motor and an air propeller that is mounted above the rear float and this turns with the rudder so it's like thrust vectoring so the two front foils are basically controlled the exact same as elevons on a delta wing the rear foil is basically just an elevator for the first preliminary test i'm not using a flight controller on board i just wanted to see if i could control it manually without the help of any sensors the first thing i realized is that i did not put enough thought into the pontoon design i should have made them with steps like airplane floats so they can get up on plane easier instead they are shaped like displacement holes which makes it harder to get up off the water oh well the next problem is that the motor in the back was sucking in a lot of water this turned out to be a big problem as you'll see soon once i got it up off the water it was almost impossible to keep at the right altitude without the hydrofoils just breaching the surface and skimming on the top of the water there's a very small range of acceptable height to be at and it's tough to keep it there [Music] keeping the roll axis level was also a challenge sometimes it would just start to tip off to one side [Music] and then this happened oh what the what just happened oh it must have been the esc oh no it just lit on fire oh this is the worst the esc must have been overloaded because of the water getting sucked through the propeller luckily there was an ever so slight onshore breeze that blew it back so i did not have to go swimming i might not have throttle control but at least i have rudder control so that test did not seem very promising but in the next video i'll install a flight controller onboard and see if all the high speed sensors and control loops can pilot this thing better than i could the results will probably surprise you so stay tuned a few days ago i posted the snow cat up on rctestflight.com for pre-order the first batch of 115 pieces almost completely sold out in one week i could not believe it i should have done a bigger batch you can now pre-order a kit from the second batch but that will likely not ship until later in the winter manufacturing takes a while it's definitely a bit intimidating to have all these orders piling up but luckily i'm using squarespace in their ecommerce tools so processing all these orders will be just about as easy as it gets i also used squarespace to build the website and it's definitely my preferred website building platform of choice i've been using squarespace for several years now and i can honestly say it's the best website building tool out there squarespace gives people a powerful and beautiful online platform from which to create their website their powerful e-commerce tools make adding products tracking inventory and managing orders super easy squarespace extensions make it easy for me to connect third-party shipping and order fulfillment services to streamline the logistics this is going to be a huge help for the snowgap project let's just hope i can fit all the parts in my house for the people who backed the snowcap project on kickstarter i'll be using the squarespace members area it allows creators to connect with their audience and publish gated members only content they can manage their members send email communications and leverage audience insights all in one easy to use platform for bloggers creating a community on your squarespace website is easy with a fully integrated commenting system that supports threaded comments replies and likes use their powerful blogging tools to categorize share and schedule your posts too automatically push website content to your favorite social media channels so your followers can share it too check out rctestflight.com to see my squarespace website and for your own website go to squarespace.com for a free trial and when you're ready to launch go to squarespace.com rc test flight to save 10 off your first purchase of a website or domain thanks again to squarespace for sponsoring this video so that covers the hydrofoil build and initial test but i'm pretty excited for this next video because it won't disappoint that's all for now thanks for watching bye

Channel: rctestflight

Views: 123,540

Keywords: hydrofoil, rc, boat, foil, sonar

Id: xBj5gpCAPFM

Length: 10min 41sec (641 seconds)

Published: Sat Dec 18 2021