I know I’m repeating myself, but Daniel, please, please try cutting the fiberglass or carbon fabric at a 45-degree angle instead of along the fibers. This advice comes from someone who has worked in a composite sport boats factory for years. You’ll be amazed at how much easier it is to work with and how much stronger your parts will be. If you cut the fabric on a diagonal, like at 7:25 here, you wouldn’t need to trim it on the tip of your part, and the entire wing would be more resistant to twisting. The fabric will also adhere to the surface more smoothly. This technique has no drawbacks, only advantages. Other then that - Great Project! Thank you so much for inspiration!
Not quite. Yes the fabric would be easier to be placed over the wings, but the stiffness is reduced by that. That's because fibres are only stiff in the orientation of the fibre. For a strain not coaxial, it loses a major part of the stiffness. When designing a composite material, there are a lot of considerations. 0° orientated layers for stiffness in the main loading axis, 90° for stiffness in the other axis, 45° and -45° for adding stiffness to torsional loads. Sometimes it is better to design not for maximal stiffness, so the part has some flex. Also, the stack has an influence on the damage tolerance of the part. Calculations are possible and necessary if one wants to reach the best possible wing, but also not that trivial to do.
@@Rob1970s Sorry I'm not sure I understand you. I was referring to the fibre orientation on the part, not the fabric. But there are also different types of weaving patterns. Twill, Satin, Plain weave, unidirectional and lots more. Plain weave is the most common but for curved shape the hardest to drape. Twill might be a good option for him.
Sorry if I did not explain it clearly. It is not a trivial task to explain just with words. I'm referring to classic fabric with fibers arranged at a 90-degree angle to each other in a 50/50 ratio, as I believe this is the type of fabric @rctestflight primarily uses. I'm trying to convince him not to cut his fabric along or perpendicular to the edge. Instead, I suggest cutting a few strips of fabric at a 45-degree angle to the grain. Strips cut at a 45-degree angle are much more effective when it comes to shaping them around complex shapes and edges; they lay much more easily, especially on edges. Additionally, if we need stiffness in one direction, we can cut a strip twice as wide as needed and then stretch it. This will give us the required width, with the fibers positioned at approximately a 22-degree angle, which will further reinforce the piece. Of course, when it comes to high-performance parts, the calculations are much more complex, and in those cases, fabrics with fibers aligned in only one direction are primarily used. I was more focused on making components in a home garage setting. Sorry, @Rob1970s, but you're mistaken. As proof, I suggest a simple experiment. Take a multi-layer laminate made from fabric with fibers arranged at a 90-degree angle. Cut a circle from it and try bending it with your hands. You'll quickly notice that it bends much more easily along the fiber axis (where only half of the fibers are bending) and it's much harder to bend when you try to bend it at a 45-degree angle to the fibers (when all fibers are subjected to bending). So yes, it does matter how you cut and arrange the fabric in a composite part. Maybe one day I'll record a short video to explain it in detail.
Uh, hem, ALL materials you cut at a 45 as it is the shear angle for ALL materials. --> Watch there is some know it all who knows of some VERY odd material which does not have a shear angle of 45 degrees.......
I love how you're constantly pushing the envelope of RC aircraft, and now hydrofoil board systems! I also love how you use your 3D printing, composites, and CNC machining tools, materials, engineering design, and manufacturing skills to make it happen! As a fellow tinkerer, thank you for sharing your design, build, and test projects with us, which helps expand our world!
After seeing ProjectAir’s solar plane blow up, I definitely wanted to see the RCtestflight’s proper version of a high aspect ratio solar wing. Was great to see a glimpse of it though.
The stiffness is both pressure in the manufacturing (which you did not do) but also the direction and what kind of resin you use. There's charts online that tell you what resins you need to use to obtain stiff laminations vs more flexible ones. Afaik, boat stuff is towards the more flexible part of the spectrum, because you need to have a flexible hull. You'd need the type of resin used in things like water storage tanks, for example. I've made a couple of custom ones back in the 90's with resin specific for the purpose and those were 3 layers deep only, no pressure (only the form), and chopped strand on the exterior (first layer laid) and it's extremely stiff, which i needed for the application, because it would've otherwise made a bulge because of the weight of the water.
Resin has some effect, but the main thing is the volume fraction of fibers and their orientation. With hand layup like this, you never get a good volume fraction of fibers, so you get a lot of thickness but little strength and stiffness compared to a propper vacuum bag setup or press. The 1708 is not helping either. The mat backing is great for building thickness, but the fibers are randomly oriented, so only a few are pointing in the right direction, and the weave is 45/45, so all the long fibers are going at a diagonal, almost negating their contribution. It is good to have some fibers at a diagonal for stability, but the majority of fibers should be oriented in the load direction!
@@2testtest2 crap, i spent all that time writing my comment, but this was already here, but ill also put this here balsa wood is probably the best material for making a cheap and strong sandwich plate.
@@2testtest2 Just was about to point this out as well. In a proper design, the epoxy has almost a negligible effect on the mechanical properties. Composite material design is hard and needs a lot of knowledge to reach the optimum for the desired application. The calculation itself can be done with CLT (Classical Laminate Theory). I'm certainly no expert in this, but If I would design such a foil I would probably end up with a stack that looks like something like this: [45/-45/0/0/45/-45/0/0] then followed by the foam and the same stack on the other side. The 45 degree fibre orientation helps with torsional loads which are fairly important in this twisted foil design and placing them on the outside helps to reduce the risk of delamination.
@Raxdflipnote has warned us about the "MARIAH CAREY ENTITY" waking up this soon christmas just like the previous gaurd @Frosted_Derp . Be wary of going to antartica during this period as you may experience hallucinations and other phychological symptoms. Just dont go there please and may god bless us
You are getting closer to what I see as a boat that doesn't float and a plane that doesn't fly, but together they sail very well. Glider foil for below and above. Ground effects on a water rail. The top wing might have to rotate on the bottom wing, like a sail rotates on a keel, but the ground effects would point the foil into the wind. It would be cool if it could launch from one swell to the other, Thanks for being interested in this.
@@fookingsog I have no idea what else he could have said 🤷♂️....also don't understand how he was getting semen in his socks. But there's a lot we don't understand about America so 🤷♂️
@Raxdflipnote has warned us about the "MARIAH CAREY ENTITY" waking up this soon christmas just like the previous gaurd @Frosted_Derp . Be wary of going to antartica during this period as you may experience hallucinations and other phychological symptoms. Just dont go there please and may god bless us
@Raxdflipnote has warned us about the "MARIAH CAREY ENTITY" waking up this soon christmas just like the previous gaurd @Frosted_Derp . Be wary of going to antartica during this period as you may experience hallucinations and other phychological symptoms. Just dont go there please and may god bless us
Shear Web for stiffness. Without that the foam is carrying the shear load between the two reinforced skins. And foam is flexible so the structure is too.
My thoughts exactly. With the foam in the middle connecting the two laminates it is like taking a metal or whatever I beam and replacing the middle vertical part with a flexible foam. That is such an obvious mistake. And thanks for the term 'shear web' :) Didn't know that. I've designed and built lots of industrial machines the past 40 years or so but never anything with wings. Now I kind of want to (do wings)...
From my experience building longboard skateboards from flexy carver or cruiser to full on downhill boards, I would think that small amount of straight strand carbon fibre does more than you think. It has completely different properties from glass. Glass is flexible and bouncy and carbon is much stiffer end springier. It does break at a lower deflection compared to glass and it shatters while glass tears. But on flexible sports equipment you're riding you can defilitely feel the difference in flex and damping between different materials or combination of materials.
Bro my dad had issues with shoulder dislocations when he was younger. Ended up avoiding surgical intervention by listening to a friend who was a gym owner. He built up the muscle in,his shoulders and never had a problem since
@UnitSe7en No, the horizontal stabilizer does provide a negative pitch up moment (its lift varies with aoa), so in response to a pitch disturbance the aircraft will counteract that disturbance trending towards to steady level flight; this is static stability. Dynamic stability is the tenancy of the aircraft to not oscillate and has to do largely with the damping coefficient of the aircraft as a whole, which is related to but certainly not caused by the pitching moment provided by the read stab.
This is an excellent observation! I think that the most important thing paired with this is that while his wing may be statically stable, it may also be dynamically (over-)damped which would preclude the dynamics necessary for pumping.
Nice build! It looks like you would benefit some from vacuum bagging more of the laminating steps, pre-coat the foam etc. Not only save weight but makes for quicker and stronger/stiffer build, since you mess around less with epoxy saturating the fibers. No need for peel layer that covers "everything", use only very narrow peel strips and somewhat dense pattern of outlet holes to allow transport of air and excess matrix. For the areas in between you use somewhat thicker plastic sheets that allows see through and that leaves smooth shiny surface. Also, do not sand in between layers, instead time the gel state, do a quick clean up with razor sharp blades (tons of), and just continue with next layering step. 😅
Well spotted! Congrats. I wanted to tell you that Kazuhiko Kakuto in Japan built the Flappter from Laputa Island in the Sky and the Mehve or Möwe jetwing from Nausicaa as a working RC model. And then I wanted to end my reply saying that technically you could build a Mehve but thankfully nobody , not even James 'let's stick a rocket engine in it and make it go faster' from ProjectAir would be bonkers enough to try and fly a full size Mehve with an actual jet engine... But I googled "flying machine from nausicaa valley of the wind" and ... Wow.
It'd be really interesting to setup a solar plane to use some kind of parabolic mirrors that keep the sun in line and a little steam engine to power the flight. That would be a hard challenge since those mirrors aren't aerodynamic at all and you'd have to keep it facing the sun just right at all times in order to keep the water hot enough to create steam to run the motor. It's kind of a crazy idea but I've never seen anything like it before- just a suggestion, you could be the first!
This build is awesome! I wonder if adding self-balancing tech, similar to what Segways use, could help maintain the hydrofoil’s angle relative to the board, stabilizing it for a smoother ride. Maybe actuators could automatically adjust the angle for optimal lift and control. A joystick on the board could also give riders the option to manually adjust the height by shifting the foil’s angle in real-time. For an advanced twist, the actuators could even oscillate the foil angle slightly, generating a form of propulsion by mimicking a fish’s tail movement. This could add some extra thrust without relying on traditional motors! And with independent control of each end of the foil, the rider could achieve left-right 'yaw' turns for better maneuverability. This project has so much potential!
Back when I was building balsa planes I think they called that twist in the wings “washout” 🤷🏻 Also, I recently learned about a product called “peel ply” that reduces the amount of sanding needed for fiberglass layups.
Thoughts on polyester resin? Would completely remove the need to sand in between layers as it chemically bonds as long as you make sure it doesn't contain the wax additive, which rises to the surface as it cures, depriving the resin of oxygen and allowing it to cure fully. Without this the surface remains tacky for days/weeks and can have more layers added.
This vid really resonates with me! I see so many similarities to my custom work and projects. I use the same chip brushes, the same pink foam, and the same Mitutuyo calipers. I don't have a CNC router in my shop and this makes me want to look into that. Within DIY UA-cam I see an overreliance on 3D printing and an under-awareness of the benefits and ease of composites. Thanks for putting it out there!
The difference between your fiberglass plate and the purchased one is epoxy vs. polyester resin. Epoxy is very flexible and so is glass fiber. Polyester resin is used with glass because it's stiffer and compensates for the flexibility of glass fiber.
Hi. You can significantly increase the processing speed with the "Parallel" strategy. The direction of movement should be along the diagonal of the axes of the machine. Then the maximum speeds of the axes will be vector-folded and the milling cutter will be able to move noticeably faster. Good luck with the machining :)
McNair Marine was first to build fiberglass boats using vacuum bags back in 1967. The original application of the vacuum bag technique of fiberglass molding was the Radar Dome on the A6 Intruder. My father ran Grummans Flight Test Department and help develop the process.
If you need long reach mills for a cnc router, consider Helicle's "solid carbide high feed" mills. They are specialized mills which translate forces axially instead of radially. This allows you to reach further without fear of high leverage forces. There is a learning curve because they work differently than end mills
around the 15 min mark when you were looking for the balance point while riding on your stomach: take a cue from surfers. In surfing, during takeoff on a wave you adjust the CG simply by straightening out your arms and doing kind of an upward dog to pull back, or pushing your head and chest to the board to move it forward.
If you need stiffness, US Composites has S glass. Most fiberglass is E-Glass or electrical glass, so good enough for electricals and insulation. S-glass is structural, with S-2 being a trademark name. It has quite a bit more stiffness and strength while still being fiberglass, so not a big price jump like carbon. Shoutout to Soller Composites, he got basically the cheapest carbon you can find, in the categories they stock.
S-Glass is 10% stiffer and stronger than E-glass. It is 300% more expensive. Carbon is 5x more expensive and more than 2x stronger, so it has nearly replaced S-2 in most composite products.
Its called washout on tips. Wire cut foam cores with built in washout is your building board. Carbon leading edge say 10mm deep and trailing edge 20mm deep Shear Web Spar 15mm with end grain spruce. Cover with aluminium sheet similar thickness to Coke can using slow cure epoxy weighted down on your core mould - Super strong wing 🛫
nice job. If you ever feel like making that Solar plane again I bet one of the shrink coatings used on RC planes would work great. They do come in Clear. Monokote and ultra cote are the only brands that come to mind.
Totaly crazy! Soooo much work to build this wing. Hope it will works to pump. Looks awesome. I also built some Waveboards, but this is absolut crazy. Hope you become real success with this concept. Go on! 🎉
Solar Planes is my main reason for subscribing to this channel. Incidentally, it would seem I was unsubscribed somehow. Please keep making solar planes. Ultimately I would love to see you make a solar plane that can fly 24 hours.
Ah... The solar planes... The reason i started watching this channel. I loved those videos. But Ive also been fascinated by these hydrofoil videos and the autonomous boats. All stuff I'd love to be able to do, but dont have the money or patience to achieve.
When comparing costs (make or buy), do not forget that your time is also valuable! If you feel like doing it yourself anyway, because you want to, that is a separate thing :)
True but for youtubers, time they spend working on projects is compensated to some extent. What I mean is, if you are a maker type of youtuber, then making stuff is your job. Viewers indirectly finance whatever you are working on. So the economics are different compared to non-youtubers. For a non-youtuber, it is a mistake to ignore the value of their time. But for a youtuber, it is different. Few people would watch a video of RC testflight selecting the best wingfoil online shopping. But a fair number of people will watch the video of him making a ridiculous (in the best way) wingfoil to play with.
Cool video. It reminds me of first attempts at making RC gliders. Once you have had fun with that, you need to move to vacuum bagging. You also must add some carbon layers though expensive I know. That will make things stiff and stick together. You are essentially building modern RC airplane wings, so no reason to reinvent though the hand lay up method can make good looking parts. The buoyancy thing may be an issue once you do it right as it will be lighter. Still fun to see people take a shot at composite layup.
Someone else in the comments mentioned this but I wanna say it as well to bring more light to it! WEAR MORE PPE! Get an exhaust fan or something additional too. You’ve been working with epoxy a lot lately and while it’s cool, that shit is sooo bad for your lungs
Excellent build and excellent video. I suspect that the masts of these craft replace a large amount of the pitching up moment that is usually solely born by the horizontal stabilizer on traditional aircraft. They can do so with their drag, rather than the traditional negative lift that the horz. stab. uses. If you have a dual masted board like this, I think you would need even less reflex than if it only had one mast. I see evidence of this when I see how small the horz. stab. is on other wing boards, especially when compared to the wing. Its much smaller than you would expect if it were going to be an airplane. This wing is so nice though. If it still wants to pitch up after more practice, you can always add adjustable, unpowered elevons that can be adjusted on land. Awesome vid!!!
You can cheat with the spar. If you use "flat" 5mm/1mm carbon ribbon glued securely so it can't twist you can get a huge amount of bending strength without a large tubular spar. Gluing 2 flat bits along their length greatly increases the strength.... like a split-cane flyrod. I used this to reinforce my "Skywalker FPV" 2 meter span, with a take off weight, all batteries, cameras etc, of 1.4Kg. Because the tips "could" technically twist under extreme G (4 or 5G) it actually helped wash out the tips and made the thing ultra stable in stalls. I never did loop it. Thats a lot of weight for 2 meter square, low aspect wings. I did try and stall it and had to abort. It didn't stall, it just "elevatored down" retaining a high angle of attack and I immediately dumped the nose and powered out, knowing what was coming if I pushed it too far or if I slammed the throttle open. A flat spin. Still, thing flew like it was on rails.
To keep parts flat or to desired shape, build an 'oven' -simple cage with light weight foil faced insulation that you can set over your part. Add a heater with thermostat, leave the part under vacuum in the 'oven' around 180f for 2 hours. It shouldn't pre-release or have any post cure warp Or, build a pressure vessel with heating like formula 1 teams do. Kind of expensive though Source; I built boats for 35 years and after, kevlar parts for race boats
Not sure if you have seen them but you can use Waves off boats for propulsion as well there are quite a few Vids of them doing this So cool can hardly wait to see your continued sucess
would you be able to retain the twist in your wings by glassing the upper(or lower) surface WHILE the wing is still in the foam-board? if you are required to flip the foam-board, you would be inserting a glassing step between cutting sides (upper and lower) on the router. this would effectively give you full support during your initial glassing pass and when the wing is ready for the final glassing steps, there would be a rigid fiberglass layer maintaining the wing-tip twist during the next glassing/vacuum-bagging step. another thought about your table size restrictions. you could cut the wing in multiple sections out of the same foam-board by using the same alignment pins you're using for keeping your upper wing surface above the lower wing surface. you'd have to have the space to hang foamboard off the side of your CNC table, but you could use multiple cutting programs (L-tip, L-mid, fuselage, R-mid, R-tip). you'd just program a bit of overlap between wing sections and index the material between programs.
Next time you need a stiff-ish plate, don't be afraid of a little plywood coated in epoxy, and reduce that sunk cost issue a bit. You get points for creativity, dedication and patience for sure! If you have a traditional job, you must be one of the stand out employees.
Very humanizing to hear you describe losing motivation on a project. I love the huge hydrofoil wing! Will you make it powered? Perhaps the slowest efoil? The most efficient efoil?
Watching the build was the best fun! I love watching you be a super smart engineer and builder. You are really intelligent and interesting! Keep up the amazing job!😊
Awesome project! Was pretty amazing to see such a cool concept is possible to be fabricated entirely at your home! I was thinking if you revisit solar plane v5 you could CNC negatives of each of the wing parts out of more foam to have a better support for the vacuum seal. Not sure if there's a release agent that would apply to the foam nicely, so might be a lot of sanding the negative foam off the fiberglass with that route.
As for overdoing stuff, here's one reason why it's better: Last time I went hammock camping, instead of overdoing the knots for my webbing(which is what the hammock attaches to) I got lazy... Which resulted in me being VERY rudely awaken in the middle of the night by way of smashing my back into the ground.. So I'd say it's waaay better to overdo things than the other way round! And if anyone wonders, yup it sucks about as much as you would imagine slamming your back into the ground from half a metre would! But thankfully I did not sustain anything more than a couple bruises😅👍
When you want something to make a smooth surface finish over top, get yourself some "glaze" at a local auto body supply. While you're there buy some "evercoat" branded filler. These products will melt PSB type foam board but I think your EPS foam is fine.
Fibreglass is durable but soft, carbon layers laid in cross fibre fashion is the one to use for stiffness (-> check how hockey sticks are made). Add aramid (Kevlar) in the impact area as carbon is brittle
However, I'd still LOOOVE to see the solar plane v. 5! Everything would come together there: flying wing, beautiful sleek design, autopilot stuff, efficiency! Maybe when you are done with the water stuff... (which is still fun BTW too)
You should try scalloping/ adding nodes along the edge of the wing like a whales fin. Also for your solar wing you should try using woven fabric instead of fiberglass it’s way lighter and I think it might actually be stronger. Adding some few layer graphene flake additive they use for concrete might allow you to get away with even less material.
I have a houseboat on the SF Bay and I'm trying to find a way to transit from MY marina 8 miles to the SF marina using EV power. The Candela is great but it's also $395k. You are an inspiration!!!
It has been a while since I flew a hang glider, like back in the 80s. They were just starting out with the double surface wings. The older ones had as much as 15+ degrees of wing twist/warp. I don't think in them they had any reflex on the back of the foil. They did have restraints on the main part to make sure that under negative lift loads, the sail did not deflate. These were tethers to the top post which are not on the newer models. I am pretty sure they incorporate that into wing design now days. Seems like most are flying the paragliders now days....
Right about the time I was also flying hang gliders. Mine was a Seagull "10 meter". A minimum wing "twist" (washout) was assured at all times by a small (some 50 centimeters) articulated strut near the wing tip, which by the geometry of the pivot point made it able to "float" into more negative angles if the flight conditions called for that, but would hit against a hard stop, pretty much guaranteeing a predetermined minimum negative angle at the wingtips, regardless of wing speed or angle of attack. Very simple, effective and safe.
I was just looking it up and I think I may have been mistaken. I think i was mistaking a bit of sag while static on the ground as reflex. Looks like they all have pretty convex foils out to the tips. Some of them might be running a lot more than 15deg washout though. Compared to the old school kite style it’s kind of inverted.
@@weatheranddarkness I think some of them had strings connected between certain points of the trailing edge and the top pf the king post. Under normal flight, those strings would sag and have no effect. But on the ground (or more importantly, in the event of a "luff dive"), those strings would effectively introduce a reflex in part of the trailing edge. You may have seen this with the wings static on the ground.
My first glider was a clone of the Seagull 3. Those old styles would/could go into "full luff dives" and just barley suitable for "flying higher than you care to fall.... My next glider was an Electra Flyer Olympus 3, I think. It also had the articulated strut near the wing tip. It may have been set as high as 20 degrees, but can't remember that far back. There was one flying wing, can't remember the name (Sundance maybe), and it did have a recurve via battens near the trailing edge. My Oly did have a clip to the top wires in the center off of the keel which prevented total collapse of the sail in thermal conditions. I would think the reflex near the trailing edge of your wing here would be unnecessary. One way to find out.... I do a LOT of swimming now days. To date, I don't think any one has figured out how to come up with a method of smoke streamers like they use in wind tunnels. I have thought about maybe a steady stream of air bubbles in one of those endless swimming pools.
Get some West systems 105 resin with 206/205 hardener. I prefer the 206 just longer cure times. 403 is a fiber pulp that you mix the epoxy in to thicken it. The 403 thickened mix will work its way into the foam a lot better than resin while also bonding nicely into the cloth. It’s a much stronger bond.
I know I’m repeating myself, but Daniel, please, please try cutting the fiberglass or carbon fabric at a 45-degree angle instead of along the fibers. This advice comes from someone who has worked in a composite sport boats factory for years. You’ll be amazed at how much easier it is to work with and how much stronger your parts will be. If you cut the fabric on a diagonal, like at 7:25 here, you wouldn’t need to trim it on the tip of your part, and the entire wing would be more resistant to twisting. The fabric will also adhere to the surface more smoothly. This technique has no drawbacks, only advantages.
Other then that - Great Project! Thank you so much for inspiration!
Not quite. Yes the fabric would be easier to be placed over the wings, but the stiffness is reduced by that. That's because fibres are only stiff in the orientation of the fibre. For a strain not coaxial, it loses a major part of the stiffness.
When designing a composite material, there are a lot of considerations. 0° orientated layers for stiffness in the main loading axis, 90° for stiffness in the other axis, 45° and -45° for adding stiffness to torsional loads. Sometimes it is better to design not for maximal stiffness, so the part has some flex. Also, the stack has an influence on the damage tolerance of the part. Calculations are possible and necessary if one wants to reach the best possible wing, but also not that trivial to do.
Fiberglass and carbon fiber are both cross fatched weave . .. it doesn't matter what direction you cut at all , it's cross fatched !!! X
@@Rob1970s Sorry I'm not sure I understand you. I was referring to the fibre orientation on the part, not the fabric.
But there are also different types of weaving patterns. Twill, Satin, Plain weave, unidirectional and lots more. Plain weave is the most common but for curved shape the hardest to drape. Twill might be a good option for him.
Sorry if I did not explain it clearly. It is not a trivial task to explain just with words.
I'm referring to classic fabric with fibers arranged at a 90-degree angle to each other in a 50/50 ratio, as I believe this is the type of fabric @rctestflight primarily uses.
I'm trying to convince him not to cut his fabric along or perpendicular to the edge. Instead, I suggest cutting a few strips of fabric at a 45-degree angle to the grain. Strips cut at a 45-degree angle are much more effective when it comes to shaping them around complex shapes and edges; they lay much more easily, especially on edges. Additionally, if we need stiffness in one direction, we can cut a strip twice as wide as needed and then stretch it. This will give us the required width, with the fibers positioned at approximately a 22-degree angle, which will further reinforce the piece.
Of course, when it comes to high-performance parts, the calculations are much more complex, and in those cases, fabrics with fibers aligned in only one direction are primarily used. I was more focused on making components in a home garage setting.
Sorry, @Rob1970s, but you're mistaken. As proof, I suggest a simple experiment. Take a multi-layer laminate made from fabric with fibers arranged at a 90-degree angle. Cut a circle from it and try bending it with your hands. You'll quickly notice that it bends much more easily along the fiber axis (where only half of the fibers are bending) and it's much harder to bend when you try to bend it at a 45-degree angle to the fibers (when all fibers are subjected to bending). So yes, it does matter how you cut and arrange the fabric in a composite part.
Maybe one day I'll record a short video to explain it in detail.
Uh, hem, ALL materials you cut at a 45 as it is the shear angle for ALL materials. --> Watch there is some know it all who knows of some VERY odd material which does not have a shear angle of 45 degrees.......
I love how you're constantly pushing the envelope of RC aircraft, and now hydrofoil board systems! I also love how you use your 3D printing, composites, and CNC machining tools, materials, engineering design, and manufacturing skills to make it happen!
As a fellow tinkerer, thank you for sharing your design, build, and test projects with us, which helps expand our world!
"The Solar Plane V5."
Me: "Hey, that looks really familiar-"
*Project Air crashing in the background*
"-just convergent evolution, I guess."
Need to be honest there should be about 40 people working on solar planes right now by statistics alone
Goated comment
After seeing ProjectAir’s solar plane blow up, I definitely wanted to see the RCtestflight’s proper version of a high aspect ratio solar wing. Was great to see a glimpse of it though.
How much epoxy did you use?
- Yes
This is secret campaign by big epoxy, I can feel it!
@@hanswoast7 set up by big milk, THEY CONTROL EVERYTHING
10 litres for sure.
@@PankajDoharey No way! More like 2.64172 gallons!
me screaming to use polyester resin
Would love to see the Solarplane V5
Same...I for one am tired of the water stuff :(
@@robe4314 It's cool, but like it's cool, planes were actually interesting for me at least
In return for the previous temu ad 😂
@@Alex-xs6ht THIS
glad to see someone using his knowledge the way he want
The stiffness is both pressure in the manufacturing (which you did not do) but also the direction and what kind of resin you use. There's charts online that tell you what resins you need to use to obtain stiff laminations vs more flexible ones. Afaik, boat stuff is towards the more flexible part of the spectrum, because you need to have a flexible hull. You'd need the type of resin used in things like water storage tanks, for example. I've made a couple of custom ones back in the 90's with resin specific for the purpose and those were 3 layers deep only, no pressure (only the form), and chopped strand on the exterior (first layer laid) and it's extremely stiff, which i needed for the application, because it would've otherwise made a bulge because of the weight of the water.
Resin has some effect, but the main thing is the volume fraction of fibers and their orientation. With hand layup like this, you never get a good volume fraction of fibers, so you get a lot of thickness but little strength and stiffness compared to a propper vacuum bag setup or press. The 1708 is not helping either. The mat backing is great for building thickness, but the fibers are randomly oriented, so only a few are pointing in the right direction, and the weave is 45/45, so all the long fibers are going at a diagonal, almost negating their contribution. It is good to have some fibers at a diagonal for stability, but the majority of fibers should be oriented in the load direction!
@@2testtest2 crap, i spent all that time writing my comment, but this was already here, but ill also put this here balsa wood is probably the best material for making a cheap and strong sandwich plate.
@@2testtest2 Just was about to point this out as well. In a proper design, the epoxy has almost a negligible effect on the mechanical properties. Composite material design is hard and needs a lot of knowledge to reach the optimum for the desired application. The calculation itself can be done with CLT (Classical Laminate Theory). I'm certainly no expert in this, but If I would design such a foil I would probably end up with a stack that looks like something like this: [45/-45/0/0/45/-45/0/0] then followed by the foam and the same stack on the other side.
The 45 degree fibre orientation helps with torsional loads which are fairly important in this twisted foil design and placing them on the outside helps to reduce the risk of delamination.
@Raxdflipnote has warned us about the "MARIAH CAREY ENTITY" waking up this soon christmas just like the previous gaurd @Frosted_Derp . Be wary of going to antartica during this period as you may experience hallucinations and other phychological symptoms. Just dont go there please and may god bless us
Crazy amount of glass/resin
For your fiberglass work: wet the foam with epoxy first, then lay the weave on top, way easier to get the fabric soaked through.
You are getting closer to what I see as a boat that doesn't float and a plane that doesn't fly, but together they sail very well. Glider foil for below and above. Ground effects on a water rail. The top wing might have to rotate on the bottom wing, like a sail rotates on a keel, but the ground effects would point the foil into the wind. It would be cool if it could launch from one swell to the other, Thanks for being interested in this.
When laying down composites, consider the bias of the biaxial cloth, and layout 90º offset each layer for extra stiffness. (2nd gen boat builder)
45 degrees*
@@couldhaveseenit You're right thank you
This sponsor is miles better good content man
These hydrofoil adventures are so fun to watch
"No annoying semen between your toes"? I would hope not!
DAGNABBIT!!! I HEARD THAT TOO!!! 😂
🤨📸
Had to run it through my mental translator to figure out what he really said.. lol
@@fookingsog I have no idea what else he could have said 🤷♂️....also don't understand how he was getting semen in his socks. But there's a lot we don't understand about America so 🤷♂️
@@nonsequitor Seam in between
"In the spirit of ignoring the sunk cost fallacy..." my brother! Haha
@Raxdflipnote has warned us about the "MARIAH CAREY ENTITY" waking up this soon christmas just like the previous gaurd @Frosted_Derp . Be wary of going to antartica during this period as you may experience hallucinations and other phychological symptoms. Just dont go there please and may god bless us
5:38 Bombas - no annoying semen between your toes
I was going to post the same thing. :D
I hate when that happens!
Does not ship ... useless then.
I had to check that's what i heard. Thanks for clarifying 😅
@Raxdflipnote has warned us about the "MARIAH CAREY ENTITY" waking up this soon christmas just like the previous gaurd @Frosted_Derp . Be wary of going to antartica during this period as you may experience hallucinations and other phychological symptoms. Just dont go there please and may god bless us
Shear Web for stiffness. Without that the foam is carrying the shear load between the two reinforced skins. And foam is flexible so the structure is too.
My thoughts exactly. With the foam in the middle connecting the two laminates it is like taking a metal or whatever I beam and replacing the middle vertical part with a flexible foam. That is such an obvious mistake. And thanks for the term 'shear web' :) Didn't know that. I've designed and built lots of industrial machines the past 40 years or so but never anything with wings. Now I kind of want to (do wings)...
If it is a high density foam it would be fine, the main problem is the bond strength
Always interesting. Never a let down. How anyone can watch this without being just a little happier is beyond me?
Bro, did you mean to write that in Valley Girl voice? 😂😂😂 ... either way it's given me a laugh 🙏👊
Put small motors on it for a high efficiency wing board that you can ride
From my experience building longboard skateboards from flexy carver or cruiser to full on downhill boards, I would think that small amount of straight strand carbon fibre does more than you think. It has completely different properties from glass. Glass is flexible and bouncy and carbon is much stiffer end springier. It does break at a lower deflection compared to glass and it shatters while glass tears. But on flexible sports equipment you're riding you can defilitely feel the difference in flex and damping between different materials or combination of materials.
Yep, my thought too. You add some carbon and the part gets 4x stiffer. Its just expensive.
Next video: "I built the worlds first liveaboard hydrofoil"
Bro my dad had issues with shoulder dislocations when he was younger. Ended up avoiding surgical intervention by listening to a friend who was a gym owner. He built up the muscle in,his shoulders and never had a problem since
3:01 the horizontal stabilizer provides static, not dynamic stability
Yes! H. stab. incidence won't correct the attitude alone if the craft gets disturbed. Only thing is does is provide a static pitch up moment.
@UnitSe7en No, the horizontal stabilizer does provide a negative pitch up moment (its lift varies with aoa), so in response to a pitch disturbance the aircraft will counteract that disturbance trending towards to steady level flight; this is static stability. Dynamic stability is the tenancy of the aircraft to not oscillate and has to do largely with the damping coefficient of the aircraft as a whole, which is related to but certainly not caused by the pitching moment provided by the read stab.
@@notravstar I was under the impression that @UnitSe7en was *_agreeing_* with you, that the horizontal stab provides static stability only.
This is an excellent observation! I think that the most important thing paired with this is that while his wing may be statically stable, it may also be dynamically (over-)damped which would preclude the dynamics necessary for pumping.
Nice build! It looks like you would benefit some from vacuum bagging more of the laminating steps, pre-coat the foam etc. Not only save weight but makes for quicker and stronger/stiffer build, since you mess around less with epoxy saturating the fibers. No need for peel layer that covers "everything", use only very narrow peel strips and somewhat dense pattern of outlet holes to allow transport of air and excess matrix. For the areas in between you use somewhat thicker plastic sheets that allows see through and that leaves smooth shiny surface. Also, do not sand in between layers, instead time the gel state, do a quick clean up with razor sharp blades (tons of), and just continue with next layering step. 😅
15:56 homie just casually whipped out the Intermediate Value Theorem in everyday life. Nice.
You make complex ideas very easy to understand while being entertaining. This is a rare skill in the business world that will serve you well.
“Nausicaä of the Valley of the Wind” vibe. 👍
❤😅😊
Well spotted! Congrats. I wanted to tell you that Kazuhiko Kakuto in Japan built the Flappter from Laputa Island in the Sky and the Mehve or Möwe jetwing from Nausicaa as a working RC model. And then I wanted to end my reply saying that technically you could build a Mehve but thankfully nobody , not even James 'let's stick a rocket engine in it and make it go faster' from ProjectAir would be bonkers enough to try and fly a full size Mehve with an actual jet engine... But I googled "flying machine from nausicaa valley of the wind" and ... Wow.
That’s what I was thinking
10:55 fiberglass underwear...
8:30 "This cloth is so thick it just drinks epoxy. And this is where the baby oil actually comes in handy..." - rcdiddyflight
Bro ur upload frequency is insane, loving the vids 👌
It'd be really interesting to setup a solar plane to use some kind of parabolic mirrors that keep the sun in line and a little steam engine to power the flight. That would be a hard challenge since those mirrors aren't aerodynamic at all and you'd have to keep it facing the sun just right at all times in order to keep the water hot enough to create steam to run the motor. It's kind of a crazy idea but I've never seen anything like it before- just a suggestion, you could be the first!
This build is awesome! I wonder if adding self-balancing tech, similar to what Segways use, could help maintain the hydrofoil’s angle relative to the board, stabilizing it for a smoother ride. Maybe actuators could automatically adjust the angle for optimal lift and control. A joystick on the board could also give riders the option to manually adjust the height by shifting the foil’s angle in real-time.
For an advanced twist, the actuators could even oscillate the foil angle slightly, generating a form of propulsion by mimicking a fish’s tail movement. This could add some extra thrust without relying on traditional motors! And with independent control of each end of the foil, the rider could achieve left-right 'yaw' turns for better maneuverability. This project has so much potential!
Back when I was building balsa planes I think they called that twist in the wings “washout” 🤷🏻
Also, I recently learned about a product called “peel ply” that reduces the amount of sanding needed for fiberglass layups.
Have you considered the I Beam effect to your composite layups? Cheaper, much lighter, and less time-consuming.
Love what you do man!
Omg dude designed a Russian uav drone 0:47
Amazing, ce gars-là a réussi à réinventer l'eau tiède, total respect... 😇
Thoughts on polyester resin? Would completely remove the need to sand in between layers as it chemically bonds as long as you make sure it doesn't contain the wax additive, which rises to the surface as it cures, depriving the resin of oxygen and allowing it to cure fully. Without this the surface remains tacky for days/weeks and can have more layers added.
Isn't that the UV Cure resin??? 🤔
Polyester resins are not nearly as strong as epoxy and will result in much higher weight layups. Definitely easier to work with though and cheaper.
This vid really resonates with me! I see so many similarities to my custom work and projects. I use the same chip brushes, the same pink foam, and the same Mitutuyo calipers. I don't have a CNC router in my shop and this makes me want to look into that. Within DIY UA-cam I see an overreliance on 3D printing and an under-awareness of the benefits and ease of composites. Thanks for putting it out there!
Looking pretty epic man! It's always a gut check to me just HOW much more torque younger off of water than air, even at low speeds.
The difference between your fiberglass plate and the purchased one is epoxy vs. polyester resin. Epoxy is very flexible and so is glass fiber. Polyester resin is used with glass because it's stiffer and compensates for the flexibility of glass fiber.
Hi. You can significantly increase the processing speed with the "Parallel" strategy. The direction of movement should be along the diagonal of the axes of the machine. Then the maximum speeds of the axes will be vector-folded and the milling cutter will be able to move noticeably faster. Good luck with the machining :)
Wow, I'm impressed with the low amount of dust on the CNC machine! Your dust collection system is very effective :)
McNair Marine was first to build fiberglass boats using vacuum bags back in 1967.
The original application of the vacuum bag technique of fiberglass molding was the Radar Dome on the A6 Intruder. My father ran Grummans Flight Test Department and help develop the process.
If you need long reach mills for a cnc router, consider Helicle's "solid carbide high feed" mills. They are specialized mills which translate forces axially instead of radially. This allows you to reach further without fear of high leverage forces. There is a learning curve because they work differently than end mills
Watched this through and impressed with your hard work and positive attitude to your projects -
Look forward to the tow test for your foil 👍
around the 15 min mark when you were looking for the balance point while riding on your stomach: take a cue from surfers. In surfing, during takeoff on a wave you adjust the CG simply by straightening out your arms and doing kind of an upward dog to pull back, or pushing your head and chest to the board to move it forward.
If you need stiffness, US Composites has S glass. Most fiberglass is E-Glass or electrical glass, so good enough for electricals and insulation. S-glass is structural, with S-2 being a trademark name. It has quite a bit more stiffness and strength while still being fiberglass, so not a big price jump like carbon.
Shoutout to Soller Composites, he got basically the cheapest carbon you can find, in the categories they stock.
S-Glass is 10% stiffer and stronger than E-glass. It is 300% more expensive. Carbon is 5x more expensive and more than 2x stronger, so it has nearly replaced S-2 in most composite products.
Its called washout on tips. Wire cut foam cores with built in washout is your building board.
Carbon leading edge say 10mm deep and trailing edge 20mm deep Shear Web Spar 15mm with end grain spruce.
Cover with aluminium sheet similar thickness to Coke can using slow cure epoxy weighted down on your core mould - Super strong wing 🛫
nice job. If you ever feel like making that Solar plane again I bet one of the shrink coatings used on RC planes would work great. They do come in Clear. Monokote and ultra cote are the only brands that come to mind.
Totaly crazy! Soooo much work to build this wing. Hope it will works to pump. Looks awesome. I also built some Waveboards, but this is absolut crazy. Hope you become real success with this concept. Go on! 🎉
@rctestflight What did you say at 5:39 ?
Unlile most socks, there is no annoying semen between your toes. No one is forgetting this ad 😂😂
@@CozzyKnowsBest And coming to the comments section just to find this discussion 😆
You and Xyla Foxlin should do a video together. You both make such incredible things. Great work!
Solar Planes is my main reason for subscribing to this channel. Incidentally, it would seem I was unsubscribed somehow. Please keep making solar planes. Ultimately I would love to see you make a solar plane that can fly 24 hours.
Ah... The solar planes... The reason i started watching this channel. I loved those videos. But Ive also been fascinated by these hydrofoil videos and the autonomous boats. All stuff I'd love to be able to do, but dont have the money or patience to achieve.
When comparing costs (make or buy), do not forget that your time is also valuable! If you feel like doing it yourself anyway, because you want to, that is a separate thing :)
True but for youtubers, time they spend working on projects is compensated to some extent. What I mean is, if you are a maker type of youtuber, then making stuff is your job. Viewers indirectly finance whatever you are working on. So the economics are different compared to non-youtubers. For a non-youtuber, it is a mistake to ignore the value of their time. But for a youtuber, it is different. Few people would watch a video of RC testflight selecting the best wingfoil online shopping. But a fair number of people will watch the video of him making a ridiculous (in the best way) wingfoil to play with.
Cool video. It reminds me of first attempts at making RC gliders. Once you have had fun with that, you need to move to vacuum bagging. You also must add some carbon layers though expensive I know. That will make things stiff and stick together. You are essentially building modern RC airplane wings, so no reason to reinvent though the hand lay up method can make good looking parts. The buoyancy thing may be an issue once you do it right as it will be lighter. Still fun to see people take a shot at composite layup.
You should make a solar plane v5 and make it do a waypoint mission to england and fly in curcles around project air to assert dominance
This guy is a full DIY wizard. Truly inspiring.
You landed a good sponsor this time. Those are some of my favorite socks.
So many parallels between aerospace and marine engineering. Great video, thank you.
Someone else in the comments mentioned this but I wanna say it as well to bring more light to it!
WEAR MORE PPE! Get an exhaust fan or something additional too. You’ve been working with epoxy a lot lately and while it’s cool, that shit is sooo bad for your lungs
Excellent build and excellent video. I suspect that the masts of these craft replace a large amount of the pitching up moment that is usually solely born by the horizontal stabilizer on traditional aircraft. They can do so with their drag, rather than the traditional negative lift that the horz. stab. uses. If you have a dual masted board like this, I think you would need even less reflex than if it only had one mast. I see evidence of this when I see how small the horz. stab. is on other wing boards, especially when compared to the wing. Its much smaller than you would expect if it were going to be an airplane. This wing is so nice though. If it still wants to pitch up after more practice, you can always add adjustable, unpowered elevons that can be adjusted on land.
Awesome vid!!!
You can cheat with the spar. If you use "flat" 5mm/1mm carbon ribbon glued securely so it can't twist you can get a huge amount of bending strength without a large tubular spar. Gluing 2 flat bits along their length greatly increases the strength.... like a split-cane flyrod.
I used this to reinforce my "Skywalker FPV" 2 meter span, with a take off weight, all batteries, cameras etc, of 1.4Kg.
Because the tips "could" technically twist under extreme G (4 or 5G) it actually helped wash out the tips and made the thing ultra stable in stalls.
I never did loop it. Thats a lot of weight for 2 meter square, low aspect wings. I did try and stall it and had to abort. It didn't stall, it just "elevatored down" retaining a high angle of attack and I immediately dumped the nose and powered out, knowing what was coming if I pushed it too far or if I slammed the throttle open. A flat spin.
Still, thing flew like it was on rails.
I don't care about what your making, I'm just here for the diy and engineering. Great videos.
To keep parts flat or to desired shape, build an 'oven' -simple cage with light weight foil faced insulation that you can set over your part. Add a heater with thermostat, leave the part under vacuum in the 'oven' around 180f for 2 hours. It shouldn't pre-release or have any post cure warp
Or, build a pressure vessel with heating like formula 1 teams do. Kind of expensive though
Source; I built boats for 35 years and after, kevlar parts for race boats
Great taste in Tevas, I've got the same pair
Not sure if you have seen them but you can use Waves off boats for propulsion as well there are quite a few Vids of them doing this So cool can hardly wait to see your continued sucess
would you be able to retain the twist in your wings by glassing the upper(or lower) surface WHILE the wing is still in the foam-board? if you are required to flip the foam-board, you would be inserting a glassing step between cutting sides (upper and lower) on the router. this would effectively give you full support during your initial glassing pass and when the wing is ready for the final glassing steps, there would be a rigid fiberglass layer maintaining the wing-tip twist during the next glassing/vacuum-bagging step.
another thought about your table size restrictions. you could cut the wing in multiple sections out of the same foam-board by using the same alignment pins you're using for keeping your upper wing surface above the lower wing surface. you'd have to have the space to hang foamboard off the side of your CNC table, but you could use multiple cutting programs (L-tip, L-mid, fuselage, R-mid, R-tip). you'd just program a bit of overlap between wing sections and index the material between programs.
Next time you need a stiff-ish plate, don't be afraid of a little plywood coated in epoxy, and reduce that sunk cost issue a bit. You get points for creativity, dedication and patience for sure! If you have a traditional job, you must be one of the stand out employees.
My man C-walkin in sandals with socks 5:39 😂🫡
bro i was looking at the coments to see if someonse noticed the clean ah cwalk 😂
Awesome stuff!
As a pro skim boarder that’s really cool. Good job building a great board which is progression in the surf world. ❤
Ailerons can substitute for reflex in a wing. You might be able to mount permanent “up” ailerons.
Also there is much confusion on the difference between reflex and washout. He doesn't seem to know.
Very humanizing to hear you describe losing motivation on a project.
I love the huge hydrofoil wing! Will you make it powered? Perhaps the slowest efoil? The most efficient efoil?
Your right, shoulda started a a specific wing and made this one into what you started.
Would have loved to see the original plan completed.
Watching the build was the best fun! I love watching you be a super smart engineer and builder. You are really intelligent and interesting! Keep up the amazing job!😊
Awesome project! Was pretty amazing to see such a cool concept is possible to be fabricated entirely at your home! I was thinking if you revisit solar plane v5 you could CNC negatives of each of the wing parts out of more foam to have a better support for the vacuum seal. Not sure if there's a release agent that would apply to the foam nicely, so might be a lot of sanding the negative foam off the fiberglass with that route.
As for overdoing stuff, here's one reason why it's better:
Last time I went hammock camping, instead of overdoing the knots for my webbing(which is what the hammock attaches to) I got lazy...
Which resulted in me being VERY rudely awaken in the middle of the night by way of smashing my back into the ground..
So I'd say it's waaay better to overdo things than the other way round!
And if anyone wonders, yup it sucks about as much as you would imagine slamming your back into the ground from half a metre would!
But thankfully I did not sustain anything more than a couple bruises😅👍
The Algorithm sent me. You earned a subscriber. Updates must follow!
as an avid pumpfoiler, I am excited for you man. Looks like you can go forever on such a wing
awesome project!!
this thing is so big, you could make the world’s first hydrofoil house boat
When you want something to make a smooth surface finish over top, get yourself some "glaze" at a local auto body supply. While you're there buy some "evercoat" branded filler. These products will melt PSB type foam board but I think your EPS foam is fine.
Polyester body filler, along with almost every other solvent except water, and isopropyl alcohol, will all melt Polystyrene.
Fibreglass is durable but soft, carbon layers laid in cross fibre fashion is the one to use for stiffness (-> check how hockey sticks are made). Add aramid (Kevlar) in the impact area as carbon is brittle
Love your total commitment to a completely TLAR project 🎉
However, I'd still LOOOVE to see the solar plane v. 5! Everything would come together there: flying wing, beautiful sleek design, autopilot stuff, efficiency! Maybe when you are done with the water stuff... (which is still fun BTW too)
The little kicks were hilarious. Cool project dude, keep it up!
This channel is equivalent to two channels in terms of video/project output. crazy.
The next step could be the world's first hydrofoil biplane, where the lower wing floats in the water and the upper wing carries solar panels👍
You should lay the FG at a 45 degrees angle to improve torsion resistance. Check dlg building videos!
Plus, please, sand the foam and vacuum bag it….
Friend / girlfriend nicely on brand with the Onshape hoodie!
You should try scalloping/ adding nodes along the edge of the wing like a whales fin. Also for your solar wing you should try using woven fabric instead of fiberglass it’s way lighter and I think it might actually be stronger. Adding some few layer graphene flake additive they use for concrete might allow you to get away with even less material.
I have a houseboat on the SF Bay and I'm trying to find a way to transit from MY marina 8 miles to the SF marina using EV power. The Candela is great but it's also $395k.
You are an inspiration!!!
I built my first airchair myself
back in the day when they came out
Amazing work ,
Keep that imagination going
I hope you make planes again someday! Flying machines are more fun.
they're not, unless you fly on them
@@1bboyred1 what? Beat it
It has been a while since I flew a hang glider, like back in the 80s. They were just starting out with the double surface wings. The older ones had as much as 15+ degrees of wing twist/warp. I don't think in them they had any reflex on the back of the foil. They did have restraints on the main part to make sure that under negative lift loads, the sail did not deflate. These were tethers to the top post which are not on the newer models. I am pretty sure they incorporate that into wing design now days. Seems like most are flying the paragliders now days....
The newer ones do seem to have some reflex towards the tip as well as the washout.
Right about the time I was also flying hang gliders. Mine was a Seagull "10 meter". A minimum wing "twist" (washout) was assured at all times by a small (some 50 centimeters) articulated strut near the wing tip, which by the geometry of the pivot point made it able to "float" into more negative angles if the flight conditions called for that, but would hit against a hard stop, pretty much guaranteeing a predetermined minimum negative angle at the wingtips, regardless of wing speed or angle of attack. Very simple, effective and safe.
I was just looking it up and I think I may have been mistaken. I think i was mistaking a bit of sag while static on the ground as reflex. Looks like they all have pretty convex foils out to the tips. Some of them might be running a lot more than 15deg washout though. Compared to the old school kite style it’s kind of inverted.
@@weatheranddarkness I think some of them had strings connected between certain points of the trailing edge and the top pf the king post. Under normal flight, those strings would sag and have no effect. But on the ground (or more importantly, in the event of a "luff dive"), those strings would effectively introduce a reflex in part of the trailing edge. You may have seen this with the wings static on the ground.
My first glider was a clone of the Seagull 3. Those old styles would/could go into "full luff dives" and just barley suitable for "flying higher than you care to fall.... My next glider was an Electra Flyer Olympus 3, I think. It also had the articulated strut near the wing tip. It may have been set as high as 20 degrees, but can't remember that far back. There was one flying wing, can't remember the name (Sundance maybe), and it did have a recurve via battens near the trailing edge. My Oly did have a clip to the top wires in the center off of the keel which prevented total collapse of the sail in thermal conditions. I would think the reflex near the trailing edge of your wing here would be unnecessary. One way to find out.... I do a LOT of swimming now days. To date, I don't think any one has figured out how to come up with a method of smoke streamers like they use in wind tunnels. I have thought about maybe a steady stream of air bubbles in one of those endless swimming pools.
15:33 the bunny kicks 😂
I've never seen a man love fiberglass so passionately
i love your danger weights for holding things down hehe , keep having fun and doing your thing
Get some West systems 105 resin with 206/205 hardener. I prefer the 206 just longer cure times.
403 is a fiber pulp that you mix the epoxy in to thicken it. The 403 thickened mix will work its way into the foam a lot better than resin while also bonding nicely into the cloth. It’s a much stronger bond.
Ever consider a CNC hot wire foam cutter? You get beds and cores in one shot!
Hey Daniel, I'll be back to see that tow boat in action.
It's going to work, no doubt in my mind.
Cheers 👍💪✌