We are working on a seastead design. Above the water there will be a big triangle frame. The left and right sides will be 70 feet long and the back part of the triangle will be 35 feet wide. The point opposite the 35 ft side is the front. The triangle frame will be a truss structure that is 7 feet high (floor to ceiling). It will be enclosed and the whole inside the living area. Lots of glass to see out. There are 3 legs/floats/foils/wings that provide the buoyancy, so it is a bit like a trimaran but with a very soft ride. Each leg/wing will 19 feet long and have a NACA 0030 foil shape with 10 foot chord and 3 foot width. Each of the 3 legs will be attached to the underside of the big triangle near one of the 3 points (but the total top of the leg will be inside the triangle) and going down so that the lower half is in the water. This makes for a "small waterline area" similar like a small oil platform but one that can move through the water easier because of the foil shape. The 3 legs will all be parallel with the blunt or "leading edge of the wing" side facing forward so it is low drag for the seastead to move forward. Each leg will be 50% under the water (so 0.5 * 19 feet) and the top 50% out of the water. On the top half of the front of each leg, so the top half that is out of the water, will be a built in ladder. There will be 6 RIM drive thrusters of 1.5 foot diameter, one on each side of the 3 legs/wings about 3 feet up from the bottom. These RIM drives will have the flat sides toward the front and back of the seastead. On top of the roof there will be solar all over. Behind the back near the center will be two supports going out and 2 ropes going down to a dinghy. The dinghy is a 14 foot RIB boat with an electric Yamaha HARMO outboard. It is sideways against the center of the backside of the living area. When the seastead is moving forward the dingy is shielded from the wind by the living area. Also behind the back on the left and right of the dinghy will be a deck that is 5 feet wide extending beyond the back of the triangle. There are 3 stabilizers that look like a little airplanes, one attached near the back of each main seastead leg. The little airplane has a 12 foot wing-span, 1.5 foot chord, the body 6 feet long, and the elevator has a 2 foot wing-span and 6 inch chord. A small actuator makes the elevator angle up or down so it can adjust the angle of attack of the main wing of this stabilizer without needing a large actuator. This is really the "servo tab" idea. While the thick part of the leg is 3 feet wide the back where the airplane will attach is very thin. And to get the airplane's center of lift to balance on the pivot a notch into the front/center of the wing only has to go about 25% of the chord of the wing. When the seastead is going to be staying in one place for awhile, we can put down 3 helical mooring screws and give the seastead tension legs so it becomes nearly stationary when parked. Two seasteads will be able to connect together with a walkway, one behind the other, so that while underway people can move between seasteads, enabling a real community. Please used Froude scaling rules to give me the dimensions of a 1:4 scale model in feet/inches. If the full scale is 36,000 lbs, what is the target weight of the scale model in lbs. I am thinking that with Starlink and 2 trolling motors we could make a model that we could send out in the Caribbean. With a video camera onboard it could be fun. Making our own solar unmanned surface vehicle (USV). With batteries down in the legs it seems it could be ok as long as there is not a tropical storm or hurricane. Of course we can easily take it out of the water if there is any kind of storm coming. But imagine we sell this and some customer has it out in waves that are too much more it, how would you describe the waves that could tip this over? With current weather forecasting and the speed of this drone, and it stays out of hurricane zones, is it practical to avoid such waves 999 days out of 1000? It seems the high solar power to weight ratio and stability that makes the full scale nice could also make a model this size nice. The weight scales with the cube and the active stabilizer area scales with the square. The solar scales with the square. So a model that is 1/4th scale can have much better power/weight ratio and better stabilizer thrust / weight ratio that the full scale. With high power it can go faster than scale speed, so the stabilizer will have very strong impact for the very low scale weight. Also, if there is a limited time of high waves the drone can use extra battery and go faster, making the stabilizers work even better. And for high waves the drone legs acting like keels/dagerboards can make running from the wind at some angle work well. If we can get this 1/4th scale model to be "safe" in the actual ocean then it should be easy to have the full scale be safe as the model is sort of testing in waves 4 times higher than the full scale version would experience. So it seems like fantastic stress testing of the control algorithms. The stabilizers could even be used a bit like hydrofoils and lift the vessel, and so reduce the amount of drag from the legs, and go faster. Please try to analyze the potential for increased speed by doing this. If we had a full battery and tried to do efficient foiling how fast could this go for how long, and so how far? We might want to put the thrusters below the stabilizer wing if there is good possibility of foiling on the surface. If the legs/floats, triangle frame, and stabilizers are all made out of marine aluminum. The triangle can be made out of extruded marine aluminum round tubing (no need for a truss at this size model) maybe 3 diameter and 1/8th inch wall thickness. We will make a netting from ropes to mount the flexible solar panels on. Maybe have a hook every 6 inches along the triangle that we can put the rope over (final design will make spacing work well with solar panel size). If every 6 inches there is a hook, and at every hook there are 2 ropes going off at 90 degrees from there for the net, how much force can the ropes put on the hook before the 3 inch tubing would have trouble? Is that enough for a reasonably tight netting so the pannels won't be sagging toward the water? Lets assume we use this solar panel: BougeRV Arch / Arch Pro 200W (Fiberglass Flexible)$238–$27023–25% (N-type TOPCon on Pro)High (~18–19+ W/sq ft)~7 lbs Dimensions: 52.95" × 30.91" × 0.1" (≈1345 mm × 785 mm × 2.5 mm) Weight: 7.9 lbs. Cost: $200 How many panels can we fit on the netting? If increasing the triangle size a small amount makes more solar fit we can do that. How many watts will that be? I am liking 6 of the Blue Robotics T200 thrusters, so we can get the high level of redundancy planned for the full scale version. Can you find a MTBF rating for the T200 in continuous ocean use? If you have the option use a average power usage level about what we expect this design would use. If we need at least 2 thrusters not on the same leg to do differential trust and make forward progress, how long would be expect to be able to go before enough thrusters failed so we could not use 2 thrusters to make forward progress? Is there some other thruster you like better? I wish there were cheap small RIM drives, but I don't think there are any. If we turn the tail on the stabilizer airplane to some angle it should rotate the wing to a certain angle, so we don't need any sensor on the stabilizer wing, right? What would be a good actuator for the stabilizer tail control? We would also like an actuator on each to lock the stabilizer (turning it into a heave plate really), what actuator would be good for that? What do they cost? We could use a number of them to patrol Anguilla's territorial waters for illegal fishing. They should not cost to much each. Try to estimate the cost if we get the parts made in China and order 5 sets of parts. We will assemble the models ourselves, and my boys work for free, so don't worry about assembly cost. If the legs are also made of marine aluminum, please estimate the weight of all the parts and check if we are making the weight budget. We have 3 part plan to recover damaged drones. 1) We will do most of our early long range testing upwind of home. If one motor fails the drone can still do differential thrust steering with the one working motor by having it do forward and reverse. This can keep the vessel pointed toward home, so legs/keels/dagerboards track in that direction as the wind pushes it. Even if both motors are out the active stabilizers can also make a differential steering system and keep the vessel pointed home. Can have one side be in a high drag angle to make that side of the vessel go back. So this solar drone can self rescue by acting like a sailboat, as long as it is upwind of home port. 2) We can have something under the drone toward the font that is either very light weight or balanced on a hinge so that when the drone is moving forward the water pushes it and it swings toward the back and mostly out of the water but if the drone stops and goes backward it lowers down into the water and makes lots of drag and keeps the drones nose and long direction pointed into the wind. It is sort of an emergency water-break that goes on automatically if the drone goes backward. This increases the chance of rescue if a drone breaks (by humans or another drone). 3) We would like a working drone to be able to rescue a disabled drone so we don't have to send humans far out in the ocean to rescue a broken drone. The current/draft idea is that the front each drone will have a bright red rope with a bright float on the end, maybe 4 feet of rope as the front is around 2 feet above the water. On the back of each drone will be a something that goes down near the surface and has a V shape to sort of funnel the rope into the point where there is a U shape that the rope can go into the the float can not pull through. There will be 360 cameras on the front and back so the operator can focus his view on the target rope. We don't send the whole 360 camera data, only the portion of current interest over Starlink. With this system it should even be possible for one drone to rescue another drone that had tipped upside down (after waves were back to normal). Once the rescue drone has hooked the rope of the other drone it then slowly heads for home port. With Starlink video an operator can probably do this (can try again and again if needed). At some future time we will get AI on the computer to drive and do the hooking. Does something like this make sense or do you have a method you like better or improvements for this idea? No need for a dinghy or dinghy mounts on this model. No tension legs for this either. We would want some LiPo4 batteries that we can fit down in the legs. If we have 30% of our weight in batteries, how much total is that in lbs and kwh? If we have a Starlink mini, raspberry pi, a couple cameras, some LED navigation lights, and an AIS transmitter, what would you estimate the "base load" or "hotel load" will be in watts? I am guessing we will typically have more solar than we can put in the batteries so we will probably go faster during the day and slow at night. Please estimate the watts we can have for the motors during the night and during the day. Don't use the last 20% of the battery. Given the leg area and drag coefficient, what sort of speed do you think we could get with those wattage numbers during day and night travel? Estimate for into the wind, across the wind, and downwind directions. The batteries will be down in the legs, and everything else will be very flat, so hopefully the wind drag is not too bad. The wind drag of the legs in the direction we are moving is low, as they are foil shape, and they act like keels or dagerboards to counter wind pushing sideways. I worry about salt spray accumulating on the cameras, solar panels, and Starlink. What would you recommend for that issue? We will probably a raspberry pi. I think I want a 2-part soft thermally conductive silicone elastomer (like Sylgard 184) to pot the computer so there is no chance of salt water getting to the computer. Maybe we can't run the raspberry too hard, but we really don't expect to. Which model raspberry pi would you recommend? We will put tall heat-sink on the raspberry pi and have it stick out above the potted macterial. The the computer can be put down in one of the legs, which are always cooled by water. The Raspberry Pi Compute Module 4 (CM4) eMMC should last better than ones booting from an SD card. Are there competing products (Orange PI etc) that offer better low power reliability for our use case? Do you think potting this way is a good way to go? I am in Anguilla in the Caribbean. There is lots of Sargasso seaweed these days. Probably we will want onboard vission/AI that will avoid the seaweed. Does not seem too hard during the day. At night will we want a headlight I guess? And the camera and headlight have to be up on a pole. Along with patrolling for illegal fishing, it might be useful for ocean research or something else. What sort of market might this drone sell to? How big a market might it be? Please describe the top 2 or 3 current USV that this drone might compete against. How fast are the? How long can they stay at sea? What sort of range per mission? What do they weigh? What do they cost? Can you run your own code on the computer and connect your own instruments to it? I am guessing they are all self righting? This is one thing we will not have. If we sold ours for twice what the parts cost, how competitive would our USV be? Some day drones like this could make food and Amazon deliveries to full scale seasteads.