Building a DIY Drone Sailboat

in this video I'm finally going to get a chance to try out RDU Pilot's sailing feature if installed correctly it should enable any old RC sailboat to autonomously navigate through a series of pre-programmed waypoints regardless of the wind direction last year I built my first sailboat using a 3D printed mold the hole was formed by covering the mold in fiberglass and epoxy it got cured in a vacuum bag and then the mold was removed by heating it up and pulling it out I also used 3D printed molds to form the Keel it was made from scrap lead and resin instead of using a canvas sail like a normal sailboat this one is going to use a wing sail I machined it out of pink insulation foam on my CNC router that gets mounted to the boat on bearings so that it can pivot freely and it uses what's called a wing sail elevator to control the angle of attack so this boat didn't work very well for a couple reasons that I'll get into later but one of which is that the Keel didn't provide enough riding Force to keep the boat upright bye oh and it's way tipped over wow sailboats are uh I don't know what to do I have this knob that controls the sail angle right here whoa do you know how to sail I know I don't ah my boat is a failure my temporary fix for this was to turn it into a trian and this at least allowed it to sail a little bit but it was a very low performance vessle it could sail across the wind decently well but it really had no hope of being able to sail up wind so step one for our modifications is going to be to ditch the old Keel when I was designing this Keel I based its size off what looked about right for a full-size sailboat the problem is that when you scale down a model its weight decreases by the cubed route while its Dimensions scale down linearly so what this means is that if you took a fullscale sailboat and shot it with the Honey I Shrunk the kid's ray gun it would probably just fall over just like my sailboat did this is why RC sailboats have ridiculously long Keels cutting the Keel off was pretty hard because it was held on with epoxy and two 5/8 in steel bolts of course those were way Overkill as Fasteners but I just used them for the weight so this boat used to have a fin Keel but now I'm going to give it a bulb Keel bulb Keels can weigh less while simultaneously having a stronger lever arm that helps keep the boat upright I 3D printed my bulb Keels bulb out of greay pro resin on the form 3 plus resin is so much more heat resistant than fdm materials wow it worked the molten lead didn't even deform it but just to be safe I stuck it in water and kept filling it up bit by bit and I only had lead explode in my face once this is just the front half of the bulb so I had to do it all over again for the back half then both sides fit together over an aluminum bar and I used fairing compound to smooth out the seam I 3D printed some leading and trailing edges to make the aluminum bar more streamlined and glued those on then I put a layer of 2 oz fiberglass over everything to really lock it all together 2 oz glass is super great for this sort of thing because it conforms to all those tight Contours really easily I covered the bulb itself in probably a minimum of three layers of glass to help keep the two halves from coming apart and to prevent the resin prints from ever cracking then all that got quite a bit of Fairing and sanding next I 3D printed this blue plastic piece that the aluminum bar would slot into that got glued into the base of the hole once the glue dried the Keel slid in and then I made a nice fillet around the joint with fairing compound and finally that got a layer of paint to conclude the Keel build the next problem we have to address is the size of the rudder it's too small the fix is relatively straightforward I just soldered on a piece of copper plate to increase the surface area this sort of thing probably should be done with a torch but I just did it with a heat gun and two soldering irons then I cleaned up the mess with a Dremel before installing the autopilot I wanted to test out the new Keel and Rudder with the boat under fully manual control so it's uh hopefully going to stay upright a lot better this video is sponsored by betterhelp hey what are you doing how bet you're staring at 8 million little tiny LED lights that are tricking you into thinking you're hanging out in a tree with me the internet is great at leading people people onto these parasocial relationships that give them a temporary sense of social gratification but your primordial brain is supposed to be chasing squirrels through the woods with your fellow tribesmen in this day and age people are really lacking the social support they need and that's where better help comes in just talking to one of their therapists can really help put you in a better mood better help has an amazing algorithm that will help pair you with a therapist usually within 48 hours and if it doesn't work out the first time you can switch therapists whenever you want with better help you can talk to your therapist however you feel comfortable there's chat phone and video call call you can message your therapist anytime and you can even schedule a live chat for later better help is all done remotely and that makes it much easier to squeeze therapy into your busy schedule if you think you might benefit from therapy you can click on the link in the description box or go to betterhelp.com rctestflight using this link helps support the channel which is super cool but it'll also give you 10% off of your first month there there have now been over 4 million people that have used betterhelp it's definitely worth trying out because improving your mental health can improve every aspect of your life now back to the video here we go Moment of Truth will it even float it might be heavier than it was before it feels really heavy oh floats amazing I'm feeling good about this the sail rotates easily now ground effect vehicles coming in hot uh the sail is same as before oh wow damn it turns well look at that it can tack that's it couldn't do that before yeah it's way better man yeah look at that it's moving man yeah going fast I'm kind of going uh slightly into the wind now as well I'm do another tack whoa oh yeah it was ripping that time I know this doesn't look very impressive and that's because it's really not most RC sailboats can go way faster than this but it's a huge improvement from before and we're still not done with all the modifications there also just wasn't that much wind here so we decided to take it to the windward facing Shore this is where it really picked up some Speed The increased wind velocity helped helped a ton and the boat was going much faster than I had ever seen it go before still nowhere near as fast as some of the high performance model sailboats but this one weighs a lot more so I never really expected it to go that fast now that I knew this boat had potential it was time to make it autonomous Ru pilot supports the use of a wind vein so that the boat knows which direction the apparent wind is coming from the wind vein actually isn't completely necessary you can just manually tell the flight controller which heading the wind is coming from but getting consistent live readings from the boat is going to be much more accurate especially if the wind direction changes over the course of the Waypoint mission for my wind vein I'm using this as5600 hall effect encoder basically this thing just measures the orientation of a magnet placed directly over the chip so I designed a little housing with a bearing and a bolt in the middle to act as the shaft then I glued a diametrically magnetized magnet onto the end of the bolt by the way if you want the cad for this wind vein or any other part of this boat you're in luck because the native design files are available at the onshape link in the description onshape is a cloud-based CAD program that is free for hobbyists so just sign up using my link and you can edit or download all the native design files rup pilot doesn't officially support this sensor yet so I'm using its analog output feature and I added a little RC filter on there to smooth out the signal a bit here you can see the magnet and it gets positioned directly over the hall effect sensor those two halves get screwed together and the whole wind Vin assembly gets mounted on the front of the boat the vein itself is just made from a thin piece of foam and I glued a nut onto the front to balance it it needs to be balanced since the boat isn't always going to be perfectly upright okay on to the next problem sailboats need to be aerodynamically and hydrodynamically balanced so that when the wind blows on them from the side they don't turn towards or away from the wind too much there are two terms to know here the first is the center of pressure when the wind blows on a boat the center of pressure is the center of all the drag Force combined or in other words it's the net force of the wind the next term is called the center of lateral resistance this is basically just the same concept but for water resistance not air resistance if you push into the boat directly on the center of lateral resistance the boat won't turn at all it will just go straight sideways if you push behind the center of lateral resistance the boat will turn towards the pushing force if the boat is designed so that the center of lateral resistance and center of pressure is in the same spot it will naturally sail straight when the wind is hitting it from the side most manned sailboats want the center of pressure to be slightly behind the center of lateral resistance this is called wind helm and it's desirable for a few reasons mainly when a big gust of wind hits the boat it will turn into the wind which makes the gust less likely to knock the boat over also if a sailor Falls overboard the boat will naturally turn into the wind and the sails will stall causing the boat to stop for my autonomous boat I'd prefer the center of pressure and center of lateral resistance to be more or less in line so that the boat tracks straight and the autopilot has to do less work my original design had the sail too far forward which would give the boat a natural tendency to turn away from the wind this is almost never desirable so I needed to move my sail backwards to do this I had to cut a new deck on the CNC router I used quarter-inch plywood and added a honeycomb pattern to keep the weight down here's the difference between the old deck and the new deck you can see how I moved the wing sail mounting hole backwards by a few inches to get the center of pressure more in line with the center of lateral resistance I also added a cutout for a waterproof electronic storage container that is going to be housing the ru pilot flight controller which is one of the matec boards along with the rfd900 XU which I'm using as the control and Telemetry radio the boat is going to be powered by four 2170 lithium ion cells that are mounted in the base I got some UFL to SMA extensions to mount the antennas outside of the enclosure the enclosure got siliconed in place to keep the hole mostly watertight and I mounted the GPS Encompass module up towards the bow to keep it away from the power wires next came the RDU pilot setup this was basically the same as a normal Rover boat configuration with the exception of having to kind of calibrate the wind vein so that the readings line up with the apparent wind direction and that pretty much con cludes the upgrades same as before the air propeller on the stern is set up so that I can manually control it and bring the boat home if the wind dies but it's also connected to the autopilot I'll talk more about that later the rudder and the air motor's thrust vectoring motor mount use separate servos for redundancy but are connected to the same Servo output on the flight controller now it's finally time to test it I brought it out to the lake and there was a really strong offshore wind offshore winds are nice because they give you high wind speeds without large wind waves the downside is that the wind is usually more turbulent since it's flowing through all the obstacles on land so at first I just had the boat in manual mode controlling the rudder and wings sail elevator manually it seems to be working surprisingly well but what really surprised me is how fast it was seemingly able to go up wind and how steep of an angle it was able to sail into the wind at for those of you who don't know sailboats can't go directly into the wind or at least normal ones can't if you have a rotary sail you can I made a video about that a few months ago go check it out if you haven't seen it already but normal sailboats have to sail into the wind at an angle all the haters say saying my wing sail can't go fast it's going plenty fast this one seem to have no difficulties sailing at a 45d angle into the wind which is pretty decent performance I think it was also able to go downwind at a pretty good clip but that's a lot less impressive next it's finally time to try out auto mode so I uploaded a series of waypoints the wind is blowing pretty much straight from the south here and the boat seemed to do a pretty good job at attacking by itself to make it to an upwind Waypoint if the Waypoint was at a steeper angle than the saale noo angle so that was really cool to see and the most impressive part is that this is with pretty much all the default rilot settings the normal steering controller had to be tuned but I really didn't touch any of the sailing specific parameters it just kind of worked out of the box so that's awesome that said there was one big issue and that was that this boat usually can't make it through a tack without having to use its motor tacking is when you turn into the wind and the boat just didn't have enough momentum to make it all the way through the turn there's a parameter you can set in U pilot where if the boat's speed drops below a certain value the motor will turn on so during this Waypoint Mission the motor would momentarily come on when the boat was trying to make it through the Apex of a turn if there was an U pilot setting that would make the boat jib instead of tack I think I could get away without having a motor at all jibing is when you turn downwind instead of upwind but this feature doesn't exist so at this point I'm still pretty reliant on the motor I don't want to make this video too long so in the next video I'm going to talk more about all the flight controller's sailing features and what it's actually doing and I'll also attempt a multi-mile waypoint mission to see what this boat is really capable of so don't forget to subscribe so you never miss an episode that's all for this video thanks for watching bye

Channel: rctestflight

Views: 165,708

Keywords: sailboat, ardupilot, autonomous, rc, drone, boat, rctestflight, sailing

Id: reXc0vZ47N4

Length: 12min 46sec (766 seconds)

Published: Wed May 22 2024