RC Speedboat Ground Effect Vehicle
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- Опубликовано: 11 сен 2024
- Speedboat Ekranoplan! Use code RCTESTFLIGHT60 to get 60% OFF your first Factor box at bit.ly/3VTl8Zw
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Use code RCTESTFLIGHT60 to get 60% OFF your first Factor box at bit.ly/3VTl8Zw
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Loving the content brother! Keep up the great work!
I loved that duck that showed up at 4:52
The boat was ok too.
Pro duck trick: bread sucks for birds, it's not very nutricious but still makes them feel like they ate. A better alternative is peas or mashed corn
I'd recommend to you to look up Surface-Piercing Propellers, ventilating is a desired effect for high speed boats to avoid cavitation. It's not that much information out there but it is an interesting concept.
See my comment above.
I came across your channel around a day ago, truly a golden find.
your in for a treat lol. hes got some amazing vids
This guy really has a depth of rc beyond belief, nobody like him!!! Some of his hover craft are the best of any. Keep a eye on this guy. Somebody should hire this guy for sure.
Welcome! He's awesome and one of my favorites. The mix of info and humor, is perfect to me. Plus, I'm not nearly as bright as this guy, so it's fun seeing someone use their brain for something worth wild.
Lol
Ur late
could you try a vehicle like this but with the water propeller on a long stick so it stays fully submerged even when the rest of the craft is in the air? that would be pretty cool
Ground effect katamaran
Yea, exacly what I was thinking, like these electric foil surfboards (but not acutally having the foil, it could be omitted to keep the ground effect using aero only)
Would add a massive amount of complexity/weight, but would be really interesting if could raise/lower the water propeller so it stayed at an optimum height. Or, failing that, a height sensor to disable the water propeller if its too high to be useful.
@@Henrix1998 Yes, it already exists and it's called katamaran...
Mounting the water propeller further down to keep it submerged would have been my comment, too. That it is only half submerged is a lousy reason to say it is a bad idea if you can obviously fix that problem (there are probably other good reasons, like crap in the water). :D If it works well enough, he could do some long-run missions to check the energy consumption of water vs. air. However, I don't know how to make that a good comparison ;-)
Edit: In other words, I would like to see that vehicle be more weird ;-)
Surface piercing props are a deliberate thing in powerboats and yes they do sound annoying especially when they are powered by two huge Volvo engines.
They sound worse with 454 dry exhaust.
Looks like your most stable ground effect craft so far!
Yeah this double wing with a bit of consistent hydro drag in the rear seems like a winning combo.
I really enjoy your content, your strategy to test ideas with minimal design work and no scope creep is very inspiring. If you plan to keep trying experimental waterborne vehicles maybe its a good idea to build a service tug boat with arm/crane to rescue stuck prototypes? Such mini rescue missions would be fun to watch.
There is an analogy that comes to mind: long-tail riverboats Vietnam (they have very long motor-to-prop shafts)
They also steer with that main form of propulsion, but if you could extend the rear-prop-shaft, have it point down more and use the differential thrust of the two front props.. MAYBE that would work?
Awesome project as per usual!
edit: "REAR" prop shaft
Another great project! I also love how the reflecting water around 17:00 caused RUclips's compression algorithm to self destruct lol
Nicee build. Now you need compas, rudder and PID for direction. Just trim heading and let the controller take over.
I love the onboard shots the the aero wake, really makes you feel like you're on a full sized one looking back. I love how tech has brought backyard model making so far.
Yeah, as a 60 year old, I really feel I was borne to early. Before computer drafting, Cad/cam, 3D printing and before RC and CNC were affordable for an experimenting kid/youngster. (Of corse gyroscopes and such wasn't even available for RC applications.) I learned proper paper design drawing and casting tecniques and such. Feels very stone-age like. But most importantly, finding information was the big hurdle before the internet.
Ditto on the surface piercing props (not sure if available for RC stuff, maybe printable?), or just an extended skeg or whatever to allow the prop to stay submerged even if the tail is at the level you want. Ideally, allow the outdrive to be tiled as well. Full sized boats often will trim in to life the stern to get on plane quicker, then trim out to keep the nose highest and less wetted area at the stern only for speed.
I love ur channel
Really fast speedboats, like drag racing boats, have propellers specifically designed to mostly push air as the propeller is barely touching the water. You should look in to how those propellers work 👍
It is not really pushing air, but a very efficient way of pushing water.
that bit where it was flowing over the wake swells was amazing, i think you inadvertently managed to make your best one yet even though you got there in a bass akwards manner, also if you put movable control flaps on the front canard and tied them to the pitch axis of the flight controller, having them set up to remove lift from that front canard i bet it would stabalize and fly on just the boat propeller with the existing weight and configuration, you could also lower the height of the prop in the water
That shot when you first tested it and Rainier is in the background is really cool.
The config with the air props and 3d printed rudder was sick. It carved such a clean line in the water. Beautiful engineering.
Maybe a prop on the end of the rudder like a hydrofoil board?
Love the cinematography, as always.
Also, servo controlled hydrofoil on the end of the rudder for absolute tail height control! Woo!
I would love to see you lengthen the shaft of the propellor so that it sticks down further into the water so it doesn't exit the water at the desired ground effect height. I know you think its silly but I would find it really interesting to see a build using only water propellers.
The beauty of this craft just gliding over the water around the 15-minute mark literally gave me chills. Amazing!
It's super cool that you have so much experience at this that you can just start cutting foam and design on the fly and make something like this that works
The rudder only flights towards the end looked really great!
Finally realized why I love rctestflight channel so much! Because Daniel has never been told to think outside the Box. Can’t believe it’s been a year since the flying car.
I imagine the rudder drag gave it stability. Something more solid to pull on.
in hydrodynamics there is a principle that links the viscous friction of water with the resistance it generates on a body moving through the water and it is called Reynolds number. In this formula to calculate the friction the Reynolds number (which contains the surface of the single immersed bodies) is found in the denominator, therefore the smaller the immersed surface is and the greater the resistance it generates. in this case the rudder touching the water originally made very great resistance. the propeller on the other hand is a surface propeller created to push a mixture of water and air and be half immersed, in fact it worked quite well. in fact, racing boats do not have rudders but use a system that orients the propeller axes for maneuvering.
Beautiful video!! Keep it up !
For something you just slapped together, I think it turned out to be the best ground effect vehicle you've ever made. Worked well.
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The speedboat can become your new recovery vessel. Give it some kind of attachment/hook system so it can tow the other crafts back.
this is one of the coolest-looking vehicles you have built. The way it glides across the water is neat. I have no idea how practical, but looks sometimes have utility as well.
The rudder alone works surprisingly well, there might be more to explore there. And while I agree mainly that it's best to leave an aircraft in the air, I think a hydrofoil and\or nescelle with a propeller deep in the water could potentially not be too terrible lol.
Even with water being thrown up by the rudder, its still pushing it up not down. The water is being pushed away from the rudder outwardly and down so the rudder is being squeezed an lifted. The upward motion of the water is casued by the outward moving water crashing in to more water. The path of least resistance pushes the water up. That upward movement is pushing down on more water though not the rudder. Also, just like a diver hitting the water, a cavity is created behind the rudder. Water crashing togeather from both sides filling that cavity have nowhere else to go but up. That is also only reacting to more water, not the rudder.
While that upward water energy is not pushing down on the boat, that is energy the boat created. Energy is being robbed from its forward momentem to create the outward movement of the water. So the water shooting up is not pulling it down, it does mean the boat is going slower because of it.
OK! Awesome work!!!
NOW do a water based ground effect vehicle, but you're not allowed to use propellers to generate thrust in the air! You can only use propellers in the water! So it has to fly in ground effect, but get all of it's propulsion from pushing against the water!
Also, read up on surface piercing propellers!
You are one of my favorite RUclipsrs. I see one of your videos released and I drop everything. lol Thank you for being funny, informative, and just fun.
PLEASE PLEASE PLEASE! we need more videos! I absolutely love this channel and every video! Keep pumping them out please!
I’d imagine that weight would be something that stabilises such a vehicle. More power to keep it moving, but very stable.
Love watching channels like yours
Daniel you have found the best way to maximize fun while minimizing expenses. RC hobby was very expensive before everything was manufactured in China. You grew up at the perfect time to take full advantage of your engineering curiosity without breaking your teenage budget. And now all those years of fabrication have led you off into so many fascinating and entertaining directions.
Thank you young man for all of the content and keep up the good work.
17:35 and here we see the mating ritual of the foamboard experimental rc watercraft. incredible.
It looks incredible drifting through the corners. Races would be epic.
PAR thrust pitch control with high gains was the best ground effect control application yet. Simple and self stabilizing regardless of water surface wave action. Think you're on to something Daniel.
BTW: the rear fins should be taller, given all the turbulent air coming off the front canard, batteries and other stuff. It's like the fins were low riding in the rumble seat. With taller fins, you should be able to drop the water rudder and cruise on air motors only with good yaw stability.
This build "almost" reminds me of the TYCO Hovercraft they sold back in the 1990s!
To resolve the water flinging of the Boat Prop, maybe add a "Cylinder/Venturi?" around it to force the water backward?
Have you thought of Vacuum Forming your own Boat Hull and having 4 Pitch Control Blades and 2 rear rudders?
I like the shot with the boat heading toward Mt. Rainier.
I really like the combination of twin hulls with rudder and PAR thrust. Looks stable.
On another topic, I wish there was a cheap personal water craft that uses this combo.
Epic
Regarding the propeller throwing up a lot of water you might want to read up on Surface Piercing Propellers. These are intentionally designed to work partially submerged and they have some interesting properties. You find them mostly on high performance powerboats where their ability to work at really high RPM where a normal propeller will cavitate.
That’s what this is…
@@rctestflight Indeed, but they are very sensitive to height in the water, at this small scale a few mm up or down is enough to totally throw it off. Thats not even mentioning the angle the craft and therefore the propeller which is also sensitive.
Not so much only the rpm, in fact thats often not really a factor. Primary usage as far as I know is because it allows you to get any driveshaft/gearbox attached to the propeller out of the water, decreasing drag.
@@rctestflight Thing is you design a surface piercing prop differently than a normal prop. It's larger and the profile and attack angle of the blades is different. I don't remember the details but the fact that it's only partially submerged reduces drag and the way it changes cavitation behavior allows for higher speed at the blade tips, so higher RPM for the size than for a normal prop.
I think this is my favorite of all your groundeffect projects.
There are hydrofoil motor boats that use a propeller on a longer shaft which ensures it stays well underwater even at full speed/lift. It will only worsen the catching on weeds problem though.
Cool video on a very cool craft.
This air/dual prop combo has the same issue as hydroplanes. With the prop in the rear, any air that gets under the front will push it up while the motors are still spinning pushing it whatever direction the bow is pointing.
About 35 years ago I did some testing with basically a hydroplane but with the motor mounted in reverse in something of a V-drive setup. The key difference was that the prop was further forward. My idea was that it was still far enough back to get efficient bow rise and air entrapment, but then it wouldn't drive a blow-over as far.
I found that to be quite effective, but didn't solve blow-overs completely in my scale models. Another thing I thought of years later was that hydro's do lose propeller blades on occasion since they can turn up to 15k RPM. If that shot into the hull of the boat it could be catastrophic at speed. It is bad enough to to unbalance issues even if it doesn't hit the boat.
Something you may not have known is that many racing boats actually DO have their propeller half out of the water (and they're designed that way)
Been a while since I was learning about it, but I believe the purpose was to have each propeller blade leaving the water to avoid inefficiency due to cavitation.
That probably doesn't change the conclusion you reached (due to scale and type of operation) but worth knowing that:
A) propeller partly out of water is not by definition "bad"; and
B) water sent upwards is also not always bad (water is always sent out in all directions, you just don't see it when it's all underwater)
Obviously, the rudder sucks out a lot of energy, but it is really nice to see how much more "grip" the plane has to do tighter corners :D
Gorgeous shots from 4:00 to 4:30!
That ad section is truly a lesson in how to grab the viewers attention!
High speed props actually work better when they are only 1/2 in the water. When the prop is submerged it has lots of bite and lots of load, but with air the prop frees up, spins a lot faster with the same torque, and the water it pushes flies backwards at a much higher velocity. Counterintuitively making it more efficient.
That being said most RC boats don’t work as well as full speed ones. It would work better if it had more propeller blades and in this case the prop was lower.
Unlimited hydroplanes are a much better example than tunnels, they actually have control surfaces and in glass conditions only the prop touches the water. Tunnels only control the angle of the prop. It would have been cool to see you attempt an automated rear pitch control version of this, like trim tabs that full size flatbottoms have, or a trim of the prop angle like tunnels or catamarans.
logic still building instead of rapping... i respect it.. been loving the channel for years keep it up!
1:27 best part
The version with the propeller and motor removed is the best ground effect vehicle yet. Skimming millimeters above the surface, only the edge of the rudder carving the water.
Add a longer rear propeller shaft with a reinforced guide tube and lidar that reduces the propeller output once the craft is airborne enough to utilize ground effect but doesn’t let the propeller exit the water. Also play with rudder length and angle.
Would never have expected this to work so well - great build!
Take a long look at some Thai "long-tail" race boats. Notice that a vertical pivoting prop shaft allows dipping the prop deeper. Seems to also help keep the nose down because the pivot is balanced against the CG in a way that will keep control over the nose. Brilliant. Under the hull is a notch that causes airflow lift. There are YT videos that clearly show, that at full speed, often the ONLY thing in the water is the prop shaft... and it's fully submerged.
Just an idea that may inspire something in your head....
Coolest ground effect vehicle in most effective you've made so far
Been watching this whole series from the start. This might be the coolest one so far. That first shot at 7:30 was so perfect 👌
Gotta love that fork eye view during the ad
i'm surprise after all this boat project you don't have a tow boat to scoop them out easily. Nice video by the way always waiting your next one
Loose the underwater prop. As the craft lifts, you can see the prop torque kicking the back end to the left. It will do this every time unless you add a counter rotating twin to neutralize the difference.
Very cool build, thanks for the video!
in the last test, i think the hull on the front is adding too much drag, so that's probably why the propeller was having a hard time trying to get the entire hull up to speed.
if you've seen those longtail riverboats from SEA, they use very long prop shafts to keep the propeller submerge, you could probably do the same to also keep it in, or put the submerge the motor and the prop but that'd be more like a hydrofoil with an engine inside.
Amazing model, great how the ground effect is snapping in. I believe this mixed solution will be the more efficient up to certain speed, the bottleneck is created by extra drag from stabilization
It's great watching you experiment with things you're interested in!
I wonder if you could build up enough speed with a Jet-Ski style motor/impeller. Then you wouldnt need the adjustable PAR thrust system and wouldnt have any extra drag when you left the surface of the water.
I race Rc Tunnel boats, they're good fun! But the way it looks with the wings it reminds me of a 4 point Hydroplane. Great video!
If you want to build a ground effect vehicle with a water propeller, something like those Thai Longtail river boats might be a good idea, the propeller sticks out way behind the actual boat so it could probably be fully submerged while it's flying
I would really, really, really love to see a "Flying Fish" type vehicle, essentially a plane that gets its thrust from a prop mounted on a long, low-swept tail that stays in the water. As real flying fish "fly," they occasionally flap the tip of their tails in the water, which provides sufficient propulsion to stay airborne for (relatively) HUGE distances. I suspect it would be technically challenging to make something like that work, but if you were able to, I think it would be not only cool, but could potentially be revolutionary.
Really fun! Loved the slowmo shots. Also the food looked delicious ;)
Watching the ground effect over water is so satisfying!
2:49 You know it’s going to be a good day when you put a flight controller in a boat
Knew it! Ekranoplan flies/floats again!
4:43 ok mr dahmer glasses
On the point about water motors and rudders causing drag, I'd be tempted to treat them like landing gear on an aeroplane - retract them when you want to fly in the ground effect, deploy them for taxiing and moving like a conventional boat.
Racing hydroplanes are designed specifically so that only the tip of the prop is in the water. Counter intuitively perhaps having the prop kicking up a big rooster tail is far more efficient than having the prop totally immersed.
the ekranoplan arch will never end
Silly thought: why not use a ducted fan for the propeller, like a jet ski. an aviation style ducted fan would probably be pretty happy when it gets up out of the water and make plenty of thrust while IN. might cause a cG issue though
Great prototype! Maybe a model with submerged propeller could work even better!
Love your experiments and descriptions of them!
Tuning PID empirically, you get an eye for the Joules per second in rotational and liner axis. Different parameters for ramp up and steady state.
Awesome how useful auto stabilization in flight controllers can be...
About the water prop - I remember seeing these swamp boats that lift way out of the water and use a prop on a long shaft angled down so it stays in the water. Check it out, might be useful?
Nice Frankenspeedboat! It's ALIVE!!!
Ok so as a former RC boat guy with a few speed records I would like to say great job. But. Instead of moving the CG so far you need to think of moving the centre or pressure backwards. Try the centre of pressure of your wing at about 28% of the boats length measured from the rear. Then try and set your CG just Infront of that spot. 30% as a start. This will alleviate the need for additional weight. Also that propeller isn't great. Octura or ABC make great propellers for fast RC boats.
For the boat water propeller to work in a stable manner while in ground effect it would have to be mounted using a "saildrive" extending sufficiently deep under the bottom of the hull, so that it's never out of the water.
The final thoughts on the water made me think of moving the water prop to the middle of the craft? Cool build
I’m so glad you caught that barrel roll on the camera
Loving the G.E.V. series!!!! This was a great example
Love your vids!
Hey dude, canards in WIG's are a bad shout because the center of pressure moves forwards as you gain altitude. Super cool idea though.
put the water prop in the centre and make it a lot deeper in the water. this will mean it still has thrust in the water whilst still being able to mechanically pivot the thing up out of the water for the wings to work
Drop the water prop deeper by adding a lower unit like an I/O marine powertrain.
You should do a surface effect ship.
Probably doesn't scale well small, but russia currently has 2 in its Black Sea fleet.
Part hovercraft, part catamaran, but they're fast
You will need to lengthen that propeller shaft so that the prop sits deeper and add a few elevator controls in the front. That should do the trick
@rctestflight A lot of people are asking for a ground effect speedboat where only the prop is in the water w/o the need for front ram propellers. Could this be achieved with an actuating front canard and gyro sensor (I picture those high speed jet boats or unlimited hydroplanes)? For example, if the air gets under the boat too much causing it to flip over backwards the canard pitches down to reduce the lift from flipping over backwards. You hypothetically tune the gyro to keep this in ground effect equilibrium without touching the water or flipping backwards. This would also be very cool if you could eliminate the need for the CG to be in front the of center of lift too. If you could just whip this up real quick for your next video that would be great. :)
15:01 haha that really nice groundefect.
Please don't give up on the water-prop idea. I believe in the chimera (truly boat and plane). The angled rudder is great but put the prop on the end of it - caged to prevent seaweed etc. clogging.
You must be the world's #1 hydroplane expert now. Top notch, well done.