Building an Autonomous R/C Sailboat 

That boat hull, hmmm.

It needs a wind vane at the top of the sail to track the direction of the wind, as well as a sensor to track the angle of the sail, so it can automatically set the sail at the right angle for optimal lift/drag.

Nobody in the comments caught what you did at the beginning. You drew me in with that 3D model.

Your boat production skills are getting better and better, nowadays your boats look very decent, and smooth

0:27 - best hull I've ever seen lol

You should make a recovery boat for when test boats fail

I see what you were going for with that boat hull at :28. Nice😂

FINALLY the crossover I've been waiting for! I'm a professional rigger so if you have any questions about rig design or anything sailing related let me know!

Couple of points about going upwind efficiently: 1) it is all about apparent wind angle. Unless you have super human capabilities, you'll have to measure it on the boat. The top of the mast is the best place probably (less disturbance from the boat structure). Wether you then feed that back to your rudder mechanically or digitally, I'll let you decide 2) a front sail will increase your pointing capability a lot. I think you do not have to control it: an auto-tacking jib on a fixed rope would already do your per a lot of good Speaking of sail: high aspect ratio mainsails point better. Yours has a fairly low aspect ratio and that will hurt your perf 3) OTOH any wind drag from the structure wil destroy your pointing capability. In that respect, I am not sure what impact your elevator has. Trimarans nototriously have bad pointing capabilities because the hulls create so much wind drag. Your propeller will also have a lot of drag going upwind: it is very detrimental to your pointing capabilities 4) From a pointing PoV, a deeper keel would be a much better design choice. The more righting momentum, the better your boat will be at going upwind (pointing) OTH, looking forward to the next one

Sailor here. a couple of suggestions for making the boat go upwind better. First, use a higher aspect centerboard and lose the lead keel. You dont need the righting moment if you have amas (trimaran configuration) and the deeper draft will keep the boat from being blown sideways. Second, Id move the sail backwards a bit. the idea is you want the center of effort of the sail to be as close to the CoG as possible. With the rig as far forward as it is, you have whats called "lee helm" which is fighting the rudder servo. Ill bet you were having to hold the rudder HARD away from the wind. Dragging the rudder stalls it and of course slows you down. If the CoE and the CoG are at least close to the same spot, the boat will be a lot more balanced and will go upwind much better. You could probably get close to being able to sail at 45 deg either side of the wind.

0:28 This is definitely the hull of my boat and absolutely nothing else. Yeah, we believe you.

seeing 21 tango coming in was nostalgic. When I was a kid I spent probably ever other weekend at Seattle Seaplanes since my dad was flying there :,) Not sure if he's still around but the owner Jim used to do all the work that he was allowed to on the planes himself.

i really admire you man, i remember the old RCSuperPower days, i subbed when you made that rc cargo plane, and 12 years later you are still putting out bangers while having a full time job, idk how you do it but keep doing it

I race sailboats competitively in college, and I've been looking forward to this ever since you built your first autonomous boat! I can't wait to see how it goes 😊

"This is the Hull... for my Sailboat... then I made the Rest... of the Sailboat". You seemed a little distracted there for a bit. 🤣

OnShape is the bomb!!! It's also great that Kiri:Moto is free and now I can create toolpaths for my CNC with STLs in the same place.

Interesting hull shape, especially from the bottom view.

Awesome lesson on fiberglass molding. A friend of mine used to sell a self steering system for full sized sailboats. He molded his own steering rudders in a mold that he also made.

That beginning with the boat hull had me DYING!

The boat hull... Immediately checks comments

Genuinely my favourite youtube channel right now. Seeing all the different projects that you've done on this channel makes me want to try creating things like this too

We've built several autonomous rc sailboats, the last of which was 3D printed and 1.6m lobg with a wingsail that was 2m tall if you want the 3d files for it, we'd be happy to share them :D we are happy to help!

For a project I do for Halloween I bought some Peristaltic Pumps. They are self priming and with a small one in the boat you could pump any taken on water. The pump is ok to run for long periods of time dry or while moving fluid.

I'm an amateur sailor and I must say this I very interesting to watch! As I was listening to you speaking about air foil being more advantages than conventional sail I was screaming in my mind! But what about going down wind!? But you noticed it later while going down wind. So for your project it makes a lot of sense but on regular size boats conventional sail are better for couple reasons. 1. They can produce a lot of lift while going down wind when the foil can only use drag as you mentioned 2. You can shape the sail which is called trimming and on the regular boat that sometimes can be done with multiple ropes which adds complexity. You can make it fuller by putting your boom up for down wind sailing or flatten it for going closer to the dead zone. Or even making wind surface smaller which is necessary to keep boat steady while sailing through stronger winds. That's just my thoughts for anyone who might me interested in how those two methods of grabbing the wind my compare. t project! I will keep watching!

Try to find the max mast height and keel ratio for your hull, you can probably go further if it feels really stable.

NICE! Can't wait to see, how Ardu-Pilot will work out! BTW - you could fill the main hull with PU foam; sticking/placing table tennis balls along the bottom and gear cavity boxes (for radio and battery gear, incl. added water sealing above) vertically near the center would reduce the amount (and weight) of the foam - all with the idea to not provide a cavity for water to seep in and weigh it down or cause damage to the electronics in the 1st place. Also you might possibly want to consider a bigger rudder with at least 1/3 leading surface area to reduce servo load, thus to give the rudder much more authority (e.g. two flat thin sheets of copper or brass around a soldered brass pivot tube, pinched and soldered together along the edges for neat and simple stream-lining and then filled with PU foam)... Luv this project - keep pushing!

It’s amazing to watch the very detailed build process and then get to “I don’t know how to sail”

I built my first rc boat in 1976, a swamp buggy with a 049 pusher motor, what a disaster, from that day I hate boats and still do, haha. I have 21 years racing rc electric on-road, sponsored for a decade, as you can tell, I like precision driving, and putting it on the line. Good luck with your boat!

@rctestflight To avoid the bubbles when filling with resin, simply put a subwoofer next to it and play something with a lot of bass for an hour. That will vibrate the bubbles out. No vacuum required. Very cool watching your various techniques. One of my friends' dad has done dozens of real "flip" positive mould boat builds. I'll pass along this video, he'll get a kick out of it.

Me and a friend made a small wood Trimaran. The only RC thing about it was the rudder and a little motor in case it got stuck. My friend used to be a sailor so that was nice. The main difference on our one compared to yours is that we let the sail swivel back and forth and we had a little rope to limit the swiveling action on the sail. It actually worked quite well.

Fascinating to watch someone with no experience of RC model sail boats approach this with a completely blank sheet. Some interesting solutions here , on the otherhand even a cursory look at some RC sail boats would have pointed up the need to look at the keel depth and weight vs wind loading on the sail!

I sail a trimaran sailboat. I love it! You cannot sail directly upwind. Instead, you tack into the wind. That essentially means that you zigzag back and forth from the direction of the wind. For example if the wind is blowing from the north to the south and the destination I want to go to is directly north, then I’m going to be alternating between northeast and northwest. What you’re doing is fascinating. I’m not familiar with rigid sails and my boat has no keel, but it does have a rudder. If you get the chance, check out the Windrider sailboats. They are are referred to as armchair sailing, because you don’t use your hands, but instead use your feet for steering. I know there are many of those sailboat in your area and I’m certain that someone would be happy to take you along and try it out.

This is amazing. So excited for this project. With a small solar cell, you could go all day. I'm very interested in the autopilot capabilities.

That boat hull 3D model remind me of something. But I can't quite remember what

Your channel inspired one of our projects at university in 2020, to automate an existing model sailboat. It managed to trim a canvas sail automatically and do two maneuvers. The only worries we had was that the small basin used for testing was in an always crowded spot with constantly changing wind.

O0:26 "Hop onto the computerrrrrrr.... and..." What the heck!!?? Oh, my bad... It's a boat...😂😂😂

Holy crap, this is epic, I've been watching your incredible builds for years. I'm blown away by all the different skills you have acquired to build this one. Slightly disappointed that there is no shanty, but hopefully that'll be in part two :) Take care and keep doing what you do.

While sailing, I constantly monitor the vindex at the top of the mast, and the little wind ropes on the sail it self. These tell me how I need to position sails. Going upwind, I just tighten both sails so that they are almost aligned with the boat and check from the wind lines what is the proper angle. The boat has Raymarine Evolution autopilot with wind sensor, so it can automatically keep a set wind angle. Very helpful for long upwind sections.

Sailboats much more exciting than ground effects. Honest LOL at 0:26

I love this channel, good mixture of craftsmanship, engineering, and nature!

Little tips on the production design. You can reuse the positive mold, you just need to first produce one hull with out the rim, then the actual hull, sauna bag (This was one thing for me, so thanks) remove the mold like you did, put it into your first one fast as possible and push it in place, then put that combination back into sauna bag for little while and finally remove it to cool down. This should allow the plastic return into shape. Alternatively make the hull in two peace and fiberglass it together when mold is removed. For the gluing the plywood rim, place it into the even surface and clamp the hull down to it. With those smaller clamps you end up distorting the plywood even if its bit thicker material. Alternatively you could glue it to whole sheet, then rise it up and cnc peace out later, but this is very difficult and not worth the effort except for very special applications. It all depends on what tolerances we are talking about and how much unevenness there is to fix. In most cases your accuracy is fine, but if you really need to have it even as possible, latter method is the best. For the lead go to your local gun range, specially if its indoor and ask if they sell you some of their scrap lead. Other option is tire shop with their wheel balancing weights. If its real lead you should be able to cut them easily with pliers and mold to shape with hammer to get greater volume into your ballast weight. Mind that spray paint isint really water proof in a sense. Sure it works for test ship but for long term use. Depending what kind of resin you used you could have just dyed it red and coat the surface or better yet use top coat. Rudder tube you might want to fill with thick as you can find grease that is not water soluble as extra seal, should work fine long as its high enough and long enough, though groove and O-ring would be much better option. You can make the groove with ball head dremel bit, or even make your own cutter but drilling two holes into round rod or bolt. One that you can insert peace of hardened tool steel and another with treads that has locking machine screw in it, though for smallest of sizes you need to silver solder that tool steel in place since there is no space for the screw. "M3 press nuts" Well that would been useful to know few days ago.. well it was faster to make my own with cordless drill and angle grinder as poverty lathe from bolt, so not a big issue.

This is honestly pretty close to how real boats are constructed so this is really impressive just in buld quality alone. Great video

I'm glad you rotated that CAD drawing of the "boat hull..."

Dude I’ve been trying to figure out what the elevator was all about. Thinking to myself, airplane man trying to sail … SCOFF. But after your tutorial I’m honestly impressed. If you were to put an angle indicator on the elevator and start programming angle of attack, and tacking into the wind, you could easily make this autonomous. Again, it’s super fun watching you trouble shooting things that I deal with professionally. I want to send you a picture of some of the stuff I laugh from the research vessel, where do I send it?

Super cool project! I'll be very interested in seeing Ardupilot sail in action.

The build quality and engineering has gone up and up with every project, this one is hitting it out the park again. Your composite work is also getting much better, thank you for your creativity

Shipwright in the making. :) As a 10-year liveaboard, when I heard "water is somehow making its way into the boat" I was like... *nod* ... it be like that.

Love your video very inspiring and I increase my knowledge due to you

Nice hull

"submersible duck" WITH THE ARROW dude I can't 🤣

If you're revisiting this I have a couple of suggestions you might want to try on the control and handling front: 1. You have a symmetrical rigid sail and a trimaran setup, so barring any intricate maneuvers like luffing that you might want to do, you're generally going to be fine with just 2 fixed positions for the trim tab, so that you hit the maximum L/D angle of attack on either side of the wing, controlled by a toggle switch. That will probably simplify your workload tremendously as you can now just focus on pointing the boat. 2. Generally speaking you can sail the boat on a fixed heading or sail the boat at a fixed angle to the wind. Fixed heading will make sense if your boat is travelling at right angles to the wind (reaching), but if you're sailing into the wind or downwind then sailing at a fixed angle relative to the wind (fixed point of sail) is probably ideal. The problem here is that sailing at a fixed wind angle is quite hard from an RC perspective since there's no good indication of wind direction barring adding more sensors. One ghetto method you might want to try is to lock the rudder into a central position and add a switch-activated clutch to arrest the rotation of the sail, so that your boat is basically tied to a particular angle to the wind once you've hit the correct point of sail.

This is an interesting one..... The idea that you have more control over angle of attack is probably true at this scale, but with a larger boats (say small sailboats 100ft or less) and ropes you can approach low fractions of a degree in terms of precision. I would be interested to see a version of this that uses servos or steppers to wind some cord and control a more traditional sail. That would likely improve upwind movement and tacking significantly due to the curved profile.

You should attempt a hydrofoil sailboat next. Maybe you could even use the sensor wand with the design. Also my need a balance system.

The beginning design graphic, followed by an endless reference to the "hull" and "deck" and all the commentary about them made me giggle the entire video.

Wow that hull at the beginning was really something.

Like you said, don't make the keel heavier, make it longer and keep the mass at the very bottom only. You also need to give it a leading edge with a steep trailing angle so vegetation or fishing lines get hung up on it. You might want to integrate your keel and rudder designs to protect the rudder from also collecting vegetation and fishing lines.

For stability, check out other model sailboats and you’ll see that they have proportionally deeper keels than full size boats. They also usually use bulb keels to get a lower CoG. I think you are having trouble upwind because your boat isn’t very well balanced between CLR (center of lateral resistance) and CoE (center of effort). You might want to do some research on those. You can adjust this (small adjustments can have big results) with your rudder size or by tilting the mast.

The C.A.D. picture of your hull looked inviting.😉

Wow, appreciate all the work and workmanship you did on this boat! Just wow!

Let's be honest, 0:27 we all think the same thing with the first impression of a boat 🤣🤣🤣

Cool stuff! Part of the issue with the the single-hull-edition is how heavy your sail/mast is compared to the rest of your boat. Basically, the boat becomes a giant pendulum system when you get down to this scale. If you either reduce the mass of your sail/mast, or increase your hull/keel weight you will see improved performance. I had the same issue when I was working on my model Bluenose, it was part of why I super-sized it's rudder: ru-vid.comSRoWJFNkrf8 I made my sails out of acetate (lightweight, abundant, recycles here with other paper products), and eventually stunted my mast altogether.

I love that you include your mistakes and how you overcome them. Peter Sripol does the same thing and I enjoy both of your channels.

"... it was still really hard to go into the wind". Welcome to sailing buddy. I'd highly advise trying a day of windsurfing, it will make all of this a lot clearer.

There's a reason they dont use rigid plastic sails irl, even on rc boats

Your friend's advice is solid. Try to tack (turn into the wind) rather than gybe (turn with the wind). The latter is dangerous because the wind will suddenly push the sail across the boat, which runs the risk of capsizing due to the sudden shift in force and balance. It seems like your boat could also get stuck with the sail facing the wrong direction due to gybing. You can potentially redesign it so the sail can pivot 360 degrees, at which point you wouldn't need to worry.

0:27 Evolution and nature is one of the best engineers. Often some of the hardest engineering problems can be solved by seeing how nature has already solved the same or similar problems.

When I was a child I had an RC yacht called the KZ Kiwi. The keel was very much like yours. It was filled with lead. It was better than any other rc yacht keel design I have seen. Weed resistant and just works better.

Please bring back the "long range ardupilot mission" series with this boat with mabye make a V2 trimaran hull that is properly hydrodynamic. I love your projects.

Always creating! 😍 Love your builds and how you're always finding solutions if something is not working as you first hoped it would.

Always wanted to try rc sailing. I have a few boats and always looking at the sailboats. Just figured they would be hard to really control.

I see what you did there in the beginning, and I'm still linger-laughing 😆

there is a surprisingly small amount of drone style boat content on youtube keep it up i am always fascinated by this stuff.

That wing sail is fascinating to me. Thankyou for the introduction to it.

Just FYI at 0:26, as a naval architect, I'd recommend adding a propeller shaft with two 10gram weights to be inserted into the hull for a secondary propellant and additional stability. I would definitely make sure it's water-proof as it obviously will get wet, but that will help keep it lubricated. Prior to using it, do NOT attempt to test it out of water, as the unlubricated hull will damage your shaft - it's just a recipe for disaster. Most people typically use too small of batteries and their propeller shaft will only last for a few minutes, so make sure you supply enough power to energize the hull for at least 10-20 mins. But most importantly, just remember to not overuse the secondary propeller shaft on your hull as repeated over-use will lead to damaging the hull insert and causing you to have to keep using bigger and bigger shafts for the hull to accept. Hope this helps!

17:47 is a beautiful picture. Can be used as a wallpaper on a desktop.

Interesting video, your wing sail is interesting. However I think you can make the wing much more efficient by going to a semi rigid soft wing. Where the current wing sail is symmetric. If you go to an asymmetric sail, ( more like an airplane wing). The wing will be much more efficient. The natural pressure on one side of the wing and vacuum on the other side of the wing works automatically to shape the wing to each tack. What this does is force the sail to provide useful propulsion at a much shallower angle of attack, ( around 5-10 degrees). If you also turn your other motor on, ( the little prop in the back). This creates forward motion on the boat, making the wing sail work as a power amplifier, ( verses a conventional sail as the only means of propulsion). Doing it this way you can propel the boat in no wind at all, or any point of sail, or sail almost directly upwind with no issues. I built such a boat around 15 yrs ago, but it was a real trimaran 22 ft long and 12 ft wide. We used the boat mostly in the keys around Key West in open ocean, ( mostly as a scuba diving platform boat). We could have up to 6 passengers, and the boat cruised at 10-12 mph regardless of natural wind direction, and also in no wind at all. We had around 200 sq ft of wing sail. The weighted keel was un-necessary. Of course the boat was heavily hardened for open ocean sailing. I designed and built my own wing sails, material cost was around $300 dollars. Basic initial propulsion was provided by two small highly modified Honda outboards providing around 1hp each, running just above idle with carefully designed high pitch propellors. The boat cruised at around 10-12 mph, ( regardless of wind conditions or direction). Of course this was long before solar and electric propulsion was readily available. Actually after studying one of your other videos, ( about 72 non stop operation). And napkin calculations on the motor and power capabilities from that video, It looks like that propulsion system would work just fine on a similar boat to what I had, ( size and power wise), there is enough room on the outrigger for 1500 watts of solar, and should be able to propel you to 10-12mph cruise speed regardless of wind. Of course you would need to design much higher pitch props, ( I would shoot for around 8” pitch). With the wing sails in operation, ( amplifying the propulsion), once the wings are up and running and under way your power consumption should stead out at 300-500 watts. Propelling the boat to 8-10mph. And if natural wind is available, the power consumption could go down to zero, but you wouldn’t be able to sail directly into the wind without the primary propulsion, ( that’s just the way physics works). Just so you understand, all published knowledge revolves around using the wing sails for primary propulsion only, ( you are not doing that). And all public knowledge about propeller propulsion also assumes the propeller propulsion to be used as primary propulsion, so you are breaking new ground, ( a different concept on propulsion). My old boats, ( I built 3 in total), also had Hobie Mirage pedal drives to help with primary propulsion. Where the pedal drives provided 15% of the propulsion, the motors provided 35%, and the wing sails provided 50% of the needed propulsion. I called it a tri-power propulsion system. The boats had 300 mile range, ( with a couple extra gallons of fuel on board), and 100 miles per day, ( 10mph for 10 hours =100 miles), independent of the wind, or wind direction, ( typical wind in the keys is only 5mph most of the year). Just interesting thats all. I’m old now so I had to give all that stuff up. The whole key is multiple simultaneous modes of propulsion all working together to propel the boat.

There is something called gelcoat. Its type of thick paint to get best surface. Mold-reles agent- gelcoat- resin- glass layers. No need to putty so extensive.

That first shot of the hull bro. Dog that was wild.

@rctestflight we need some “This is the hull of my sailboat” merch! 😂

0:32 yes, the boat hull

Absolutely love your autonomous boat adventures. It even got me starting my own ArduRover boat project. When I saw the Banana Slug endurance missions I immediately thought that instead of using a lot of battery energy to fight the wind why not use the wind for propulsion? Yes, keels need to be really heavy and have a decent lever arm. I don't know about the airfoil sail. For real sailing boats being able to change the shape of textile sail is essential in getting decent performance, especially with low angles towards the wind ("close reach").

If you look at ocean cruisers, they often have a wind vane connected to the rudder. That makes them able to sail handsfree, as the sailing course angle towards the wind is constant, and then they don't need to worry about trimming the sail. If you have a course set by a GPS, a small change in wind direction would make the sail go out of trim, and ultimately the boat could stall or sail backward. Off course your setup with a vane on the airfoil will keep the angle of attack towards the wind constant, but then your course have to be adjusted all the time to be able to use the drag of the sail. I believe the boats course towards the wind is more important than the sails angle of attack to the wind. The first is essential for forward movement of the boat. The second is for optimizing the speed forward.

what a pleasure to watch and what attention to the entire video montage and images

Those desks are outstanding....

those ground effect vehicles at the end of the video seemed pretty hi-tech

I'd definitely recommend changing the aoa control method on the wing to directly driving the wing rotation with a servo. The flap at the back would be bulk drag

If you’ve ever wanted to have fun on a sailboat I recommend a pico or a topper, happy sailing!

I lost it at "Here's some ground effect vehicles" while you showed the government surveillance drones flapping above the water 😆

Impressive work. Will be great to see this go on a monster autonomous voyage.

Love your videos. This series is cool. Looking forward to the next installment.

Really like these boating videos! For better upwind capabilities, a larger/longer keel may help. Look up daggerboard or centerboard.

Yyyeeeeaaaaahhhhhhh Sailboat time!

I'm impressed with your keel construction idea, failure as it was. Would have loved to see you mess around with pouring molten lead, maybe some other time. My sloop rigged RC sailboat has a big bulbous keel that sits probably 3/4 of the hull length below the bottom. You probably could have saved a lot of time and energy by starting with an existing hull (or hull design) and put a wing sail on it. But you have a pretty consistent history with reinventing the wheel so.... "How do you think sailing works?" A lot of your ideas seem like "I have an amazing idea, let's not do hardly any research and make it look and perform as much like a brick as possible." Still enjoyable to watch. With all the leaking projects you've had, I'm sorta surprised you haven't reinvented the bilge pump yet.

I was waiting for this. A natural progression for someone with interest in the water who’s smart and daring enough to tackle aerodynamics as a main force to move around. I’m still restoring my 1973 Columbia 30 in Houston. Once I have sails repaired and the motor fixed, I’ll shoot you a dm on instagram so you can experiment with the rigging and try out full scale sailing. The bigger the boat, the faster it goes.

The boat looks awesome. Very inspiring.

Congrats on switching to Onshape, it is the future of CAD.

Great stuff as always! Thanks! I think experience with fixed wing aircraft + experience with other watercraft made transition to sailing a breeze. Huge potential w/ solar panel to drive mast/rudder angle (and cpu/radio power).

Love watching you design and build!

Channel just keeps getting better. Proud I've been with you from nearly the beginning.

god damn that boat hull looks good