Hey a tip for your air storage: people that build water rockets have perfected splicing plastic bottles together for high pressure use. The channel US Water Rockets has some good videos about bottle splicing. You could save some weight and make larger chambers fairly easily.
That sounds like a good idea if it can take the pressure. There's a lot of weight in the bottom of the bottles and fasteners. Also, here in the US we have 3-liter soda bottles. Fuse a couple of those together and you've got 50% more capacity in probably less weight.
Air Command Rockets from Australia helped me massive through my water rocket project in 10th grade. They evolved from spliced bottles to carbon fiber air tanks over the years 😅
I love the split second thought at 15:12 where you almost seem to think "I can save it!"... Immediately followed by what seems to be ..."But it might cut my finger off?" I really enjoyed this video! Well done sir.
Hi, something about your wings. Wings have the most drag at the ends because there the pressure between top and bottom is balanced and you get a whirl. For that reason the wings of a sailplane are long and get narrower to the ends. In your design there is a problem in the center too because the wings aren't connected and you loose pressure in the middle too. I think, it will already help if you connect the wings with some packaging tape. Best regards, Frank
I agree Frank, make the wings a tad longer, but tapered, i would add another 30cm, 15 each side, Tail plane needs to be a built up structure, not solid, but remain a V, as that is light, perhaps fair in the front bottle to give a more aerodynamic, and less drag from the prop going backwards, and lastly, the center wing section needs fairing into the wing and Fuz, big time, you are inducing drag, and turbulence there
Can I just say that I love everything about this series? The incremental efficiency gains, Tom's persistence, the planes themselves of course, and as a bonus, the lovely noise they make. I find it amazing that Tom keeps setting new goals and reaching them. Looking forward to the next one!
I imagine you feel the same way the Wright Brothers felt achieving their first 12-second flight. Very different problems for very different times, but you both breathe rare air.
It took him six years to get this far. Without looking at the timeframe for the Wright brothers, i bet it's pretty sad considering the education and raw information available to this propped up wannabe.
As an Engineer, i salute to your insane amount of passion you put in this airplane. It makes me smile uncontrollably to watch you progress on that project. This is nerdyness in its purest form. Thank you for your videos!
hi sir i am need of project ideas in engineering physics with practical application . i am studying 1st year and with minimal or no electronics , could you suggest some if possible
Hi Tom, epic project! I'm sure you've had lots of suggestions but I'll throw in mine anyway: 1. Replace the MG90S servos with standard SG90 servos, you don't need metal gears and this will save about 4g. You could also go smaller (GH-S37D) for a total saving of 15g and reduced size of the supporting structure. 2. Smaller LiPo pack. 3. Build up the tail surfaces from 3mm square balsa rather than sheet. 4. Taper the wings - better lift distribution and structural efficiency. Taper the spars to reflect the reduced bending moment as you move towards the tips. For tubular carbon you could glue increasingly smaller sections together, telescope style. You may need to add a few degrees of washout at the tips but this is easily done by twisting the wing to the desired angle and re-shrinking the film. 5. Lose the gap in the wing centre section and make the wing continuous. This is a big source of drag and is effectively halving your aspect ratio. 6. Add some rounded or tapered wing tips 7. Test some different props to find an optimum for this engine / airframe combination. This can make a big difference. 8. Higher pressure of course. 9. Don't use paint, it's heavier than you'd think and not needed under the film. 10. Use an iron rather than a heat gun to shrink the film. You'll have much better control and won't melt holes in it. On your comparison to CO2 canisters, I'm not sure that's valid as the CO2 is compressed to liquid phase so it's not just a comparison of ideal gas volumes. Great work though, I look forward to the next iteration.
I'm thinking tapering the wings may not help here. This plane flies super slowly, and is probably nearing the unfavourable range of Reynolds numbers, where the air starts becoming really sticky, and shortening the wing chord would exacerbate that. Perhaps adding a turbulator would help, you can try that on one wing first, which will let you easily gauge if it's improving performance (if it does, the plane will have a tendency to turn to the side with no turbulator).
CO2 transitioning a phase would make it way worse by cooling it down significantly, so if Tom's calculation is incorrect - it is incorrect in favor of air, not CO2. Also, Tom, please make a prop saver - a small modification that fastens the prop with a small rubber band instead of screws. You will easily find it on the internets by googling "propsaver"
With regards to the CO2 cartridges: A quick google says a 12 gram cartride (12 grams CO2, not considering weight of cartidge, I assume) has about 6L of CO2 at atmospheric pressure. I think it might not be worth it. It's slightly more weight, it's a part that has to be purchased *and* more strength needs to be added to the design to hold the higher pressure. Unless a larger CO2 bottle can be got easily and cheaply. Better CO2/bottle weight ratio. Thinking about the rest of the design: I think I would add a sleeve around the join of the two tanks to reduce drag. Could also have two double-tanks side-by-side (4 total), have any less aerodynamic components between them and wrap the whole thing in the film. Add a few shapers and make it into a lifting body fuselage, while we're at it.
Do not use paint, it adds about as much weight as your balsa! Instead buy colored Oracover. It has same weight as clear! Also: Look into using a folding propeller to avoid damage during landing. I am assuming power is low enough to let it fold on landing or that at least the blades will fold away upon hitting ground to avoid the snapping of motor. The rpm of motor sounds like it speeds up as the plane reaches level flight which could mean pitch is too low. It shouldn't take much thrust to keep such a sleek wing in the air, and too low load on motor in flight will just use up air.
Tom you really have outdone yourself. As an engineer I really admire the design. Hats off it really is a beautiful plane. It’s been a great journey through all the different different versions and you’ve finally done it. I love how happy you are when you see it flying. I am very happy for you. Well done !!!
Love it. You could probably reduce drag significantly if you make a small fairing to cover the gap between the wing roots and allow the air to flow around the centre piece.
Two tips. 1) I have been recycling PET diet coke bottles into printer filament for some time. My first step is to smooth out the iconic shape by pressurizing it to 70psi with a little water and heating it slowly in an oven. I've successfully shrunk, elongated in a form, and reformed the bottoms into a smooth dome. You may want to consider doing the same, giving you more volume at the same weight. Coca Cola published that their 2 liter bottles are rated for 150 psi, so if you only need 70 some experimentation might be warranted. I would love to see what you come up with. 2) Secondly, you could replace the tail rod with a pressurized fluorescent tube protector and make the plane a flying air tank. The water rocket people use them as pressure tanks as well, so there is a lot of data and technique to start with!
if the bottle was full of water before you put it in the oven and still completely filled afterwards, there would be no increase in volume maybe the sides contracted a little?
@@marc_frank - Agreed, You can't fill it up, you just need a little water to protect bottle features from overheating. You could do the same with a wet cloth on the outside. For instance, if you get the threads of the bottle too hot the deform. Not a good thing if the bottle is at 70psi. The PET recycled filament people put a small amount of water in to use steam to expand the bottle if they don't have access to a compressor.
CO2 cartridges are actually almost an order of magnitude better than that because they are full of liquid CO2 and not gas. A 16 gram cartridge actually contains 9liters of gas instead of 1liter. 6:30 MassGas/density@1atm=(16g)/(1.77g/l)=9l Easy to miss if you don't work with things like that often. Thanks for all the interesting videos and please keep them coming!
It's also not just the volume of gas, but the starting pressure. Even if there was less gas, you need to calculate the energy released when expanding to atmospheric pressure. A weather balloon stores even more air, but the pressure is so low that it can't do much useful work.
I just wrote the same as well. And there are also 20g, 38g, 45g, 74g cartridges that will have much better ratio of the useful CO2 weight to the metal canister weight. And you're getting much more constant pressure, compared to that air bottle that drops from 8 atm to 1 atm. There are problems with CO2 as well though - it will need a strong/heavy valve and you have to maintain the cartridge orientation, so you're not directly losing liquid through the valve.
@@JC-XL You also can't use the bottle as the fuselage due to the higher density - though this may be counteracted by the smaller cross section with respect to drag. Ultimately CO2 engines might perform better but they don't really meet the intent of this challenge, given the whole point is to replicate the old Air Hogs toys. I'd be interested to see a direct comparison between the Air Hogs and Tom's model. From my memory as a kid, they performed pretty well considering the small tank, stubby wings and blunt propeller.
@@JC-XL It would be interesting to see propane used as the working gas. It has a vapour pressure low enough to be liquified in a soda bottle, and also be directly compatible with Tom's engines. I believe some paintball guns use it as a CO2 alternative. While it is flammable, this shouldn't be too risky provided no ignition sources exist.
My little brother had the same air higs. We used to have so much fun with it. I was just randomly reminiscing about it to myself last night, remembering all the fun we used to have together. Crazy I come across this video the next day.
Great video as always! Here's a tip to decrease the drag and increase the lift. At the moment you have two half wings joined together at the fuselage. This design generates some vortices (exactly like the wingtip vortices) in the inner part of the wing due to the gap between the two half wings. The vortices increase the drag and decrease the lift. Joining the wing in the middle would eliminate the vortices
in general the drag of the fuselage IMO hast the biggest potential for improvement. Add a streamlined nose, cover the part where the 2 bottles are joined together, cover the center wing section and add a tail fairing to the end of the rear bottle.
I hope Tom finds this thread. This is exactly what I wanted to comment as well. At the start of the video, he made a nod to aerodynamics and did do a really good job on the wings themselves, but at the end of the video he's back to talking about weight savings. A nice, clean bulbous nose and a smooth wing root area would absolutely do wonders.
I never get over seeing the joy of a man who has built something that works but has little to no real purpose. All creator TH-camrs get it, you can always see the point it happens, right when they look at the camera and get that little smile. You know in their head they are like “it works! It actually fricken works!! I can’t believe it!” Destin got it when he split a bullet, hawinglight got when he did his perfect Japanese sparklers, integza gets it all the time lol, styropyro got it with his recent car battery monstrosity and the list goes on and on
It has little use now but it well may lead to something useful. I would not mind travelling to work one day in a CompAir car, on the fuel that my fotovolt panels made during a previous day with a electric powered compressor... or a moped or something. Start with a little thing having a bigger goal in mind, at the back of your head.
Use an electric air compressor with a WATER SEPERATOR on the line going into the Plane tank. less water in the air will reduce the weight at the end of the flight and will make your air engine run ever so slightly better. The wings seem to be a bit overkill on strength. but man this had been awesome keep this going. I know you can do 2min for sure. Great Job.
now I'm wondering is it possible to use a gas that is lighter than air, or would it turn into liquid under high pressure...and then would that even make much difference
Tom, I'm sure someone else has mentioned this before - but the CO2 canister is not actually full of gas. It's full of liquified CO2, held under that pressure. The pressure is maintained until all of the liquid has boiled off, which gives an effective storage quite a lot larger than you might think looking at it as a simple compressed gas. :)
Yep, Tom said 21 mL expands to 1 L, but they are really 21 grams. 21 grams of CO2 at room temperature is more like 10 liters! Now, it would actually be quite cold, so that will decrease performance, and the cold itself will pose design challenges
I hope he's seeing these comments about CO2 canisters. There's easily an interesting video discussing phase change and testing how the consistent pressure affects the air-engine's performance when actually flying (in terms of control). Not to mention tuning a suitable jet to meter the flow to the engine (and the cooling effect, which might not be that bad given the likely flow-rates). And, the cylinders come in a range of sizes (including much larger ones).
As I recall, Integza used a CO2 canister system, where an onboard Arduino controlled the release of CO2, using a bottle as the expansion chamber and maintaining a roughly consistent pressure inside the bottle.
a crazy idea would be to make the wings pressurized to gain more air volume, maybe some internal tube like chamber along the wing to avoid pressurizing the actual film skin
I know it's arbitrary but since it's a plane it wouldn't make sense to use lighter-than-air gases to generate lift, otherwise you could just make a blimp and easily beat the flight length record
You should look into lasercutting balsa for the flat parts (e.g. the 3d printed wing profiles and the tail flaps). It's often faster/cheaper than 3d printing, refuces plastic usage and could lead to lighter parts (though potentially also more brittle).
I FELT AS EXITED AS IF I WAS THE ONE ENGINEERING THE PLANE. I've been following your air powered engine progress since the second version and when i saw this tumbnail I audiabply gasped. I can tell how much work you put into it and it reflects on the performance. I must be honest when I started watching your videos i thought they were kind of slow and a lower form of lame, but following your ups and downs made me love and appreciate the PROCESS. You're and amazing engineer and I feel lucky to celebrate your wins!!!! THANKS FOR THESE VIDEOS, PLEASE KEEP MAKUING US GASP WITH YOUR ACHIEVEMENTS
The fact that not all his videos end in success can be infuriating, but what I love about it is that it also shows the true nature of engineering. Once he finally gets to the goal it is so satisfying!
I've followed a few of your builds over the years. When you build a wing like this it is a good idea to add some washout. This is a slight twist in the wing so the the leading edge at the tip is at a slightly lower incidence than at thee root. What this does is make the wing more stable at stall speeds or higher angles of attack. When the wing root is at a stall angle, the tip will still be flying, so does not drop one wing tip and loose a lot of height etc. The nose will drop of course, but it makes for a more stable plane. With the airfoil, the centre of lift will change with the flying speed, shifting further back the faster you go, designing your motor to run at lower speeds with a bigger prop will be more efficient too. Until the prop stops at least...
Best engineering channel on YT. The fact that everything is made from scratch and even the engine is more or less your design makes these videos so good. I have that tinkerer in me but don't have the patience and perseverance to keep at it. It awesome to see how you just keep iterating year after year on the same thing.
No, and no. This guy is an idiot relative to most. You probably are just stuck on the child-pandering tactics he's better at than anything resembling engineering.
@@ghostwhite1648bro the government isn't taking energy out of thin air, thermodynamics exists. This guy is expending tons of energy to get that air under pressure and then wasting even more to convert it back to mechanical power. He isn't taking anything out of thin air.
Hi Tom ! I was following your updates for a while. As an Air Hogs lover, I got into your journey to build your own air powered plane. Just let me say that I'm really proud of you !! 1.22 minutes is more than a sucsess !! it is MARVELOUS !! UNBELIBABLE !!! BRILLIANT !!! Your determination and your amzing skills are really impresive !!! Congratulations from Buenos Aires, Argentina !! And of course I'll be tuned to see the next flight !! Many thanks Tom !! YOU DID IT 💪💪💪!!! Hugs dude !!
One potential improvement I can think of is recycling some of the air from the expansion stroke of the motor to give the return stroke a small boost. It might even smooth out the impulse and lead to less rattling.
I was thinking this will cause the piston to move back up above the exhaust hole before the pressure has dropped enough for the seal to retract. But then I realized the seal responds to differential pressure... So if anything you'd want to create a chamber below the piston where you dump gas to hasten pressure equalization which will break the seal, and then expediate the exhaust extraction, without actually introducing pumping losses on the powerstroke. I think overall you'll have more benefits from larger exhaust port area, and maybe you can harness some efficiency by nozzling the gas backwards for direct propulsion, or directing it at the crankshaft to accelerate it through bottom dead center. But then you're going to have to consult Alex from 2stroke stuffing about how to tune exhaust pulses I think 😅
I was also thinking along these lines. If the high pressure air was applied to the underside of the piston where the surface area was a little less and then using the spent air on the conventional side of the piston it could help balance the pressure losses.
@@thegregdavieschannel but if you're injecting pressurized air on the crank side you have a larger volume to fill and will probably have airleaks around the crankshaft or need seals to minimize losses. I think both will likely hurt the overall efficiency more than you'll be able to harness with recycled gas
@@VyantQuijt some steam engines used a larger secondary compounding cylinder to harness some of the residual energy. It would be really neat to try and make that work in a single cylinder engine, but alternatively a twin cylinder engine might be the way forward.
This may be a crazy idea, but what if you had two bottle fuselages each with their own engine? kinda like a P38. Or maybe you could get four bottles together and fly it with the twin cylinder engines, which while less efficient should let you climb better and then you could glide for longer. Also the increased weight would make it handle wind better.
Assuming that your seals can take the extra pressure, or that you are able to create seals that can, if you wrap your bottles with some wire or tape, you could increase the maximum pressure that the bottles can withstand while not adding much weight.
I wish you could find some light yet strong tubes that could be used inside the wings to give it its rigidness but could also be pressurized so you have additional air capacity
Great evolution, Tom. A few suggestions to add to what other people already said: 1 - splice multiple bottles together for added air volume while shaving some weight. 2 - As you add more bottles, you might want to consider using the bottles as a structural piece to hold the tail. It will save a bit in terms of size of the aircraft and might end up saving some weight too. 3 - For the balsa wood parts, you can probably make some more holes into it without affecting the structure too much. And since we are talking about shaving some grams, you might want check the weight the paint is adding. Looking forward to the next video of the series. =)
Just echoing everyone else: it feels I've been watching you build these since forever ago and it's amazing to see how far you've brought it. Superb work.
If the tail feathers were stick-built like a typical (now considered old-school I suppose) balsa model, it would be lighter than a slab of balsa with lightening holes drilled in it. Love watching you develop this project, Tom!
My thoughts exactly. Same with the wings, and no need for the leaving edge sheeting at this type of plane. Nothing beats stick balsa when it comes to stiffness to weight ratio, maybe carbon fiber but not by much.
I have always thought that those 12 g CO2 capsules have 12 g of liquid CO2. In that case one 12 g CO2 capsule would have something like 6-7 liters of gas depending of air temperature and pressure.
You were thinking correct. He, for some reason, assumes it is just pressurized CO2 gas. At which would they could just as well have used air. The whole point of CO2 is that it is a liquid.
I've literally just paused at you pumping up the bottles "for the first time" I love your attention to detail and how much you cover each iteration. This feels like the culmination of a real journey. Hope it goes miles Excellent work.
Watching you tackle each issue that comes up and continuing to improving it at the same time so satisfying. The finished product looks so cool and seeing it successfully fly for that long was impressive.
I‘m guessing high pressure air tanks will make this unnecessarily complicated or would require molds and industrial equipment only a mass product could make cost efficient use of.
LETS GO TOM ive followed this series for years and always excited the moment i see a video. i’ve been following the engine series and knew something big was coming for some time great work again
Through many life changes and moving across the country I have stopped making models as well as stopped flying. Videos like this make me wish I prioritized the hobby more as it brings me so much joy. You have devised some incredible solutions for this project and I am so glad to live vicariously through these videos! Very well done!!
You continue to inspire me with every video! Not even my discipline of engineering but there's just something so satisfying about seeing you have these big and small breakthroughs. Counted the seconds it was flying like a bull rider on a bull. Awesome work Tom keep going!!!
Its feeling really good to see the development on this project. From one video to another you worked really really hard and finally made it. Congrats man.
To pressurise the entire wing might be worth a try, molding a "winglike plastic bottle" sort of. Maibe the "winglike plastic bottles" could be bigger and actually replace the bottles. Quite a job to test the weight/power ratio, but with 2 meters wingspan its a decent amount of volume that might be worth testing anyway. Nice work btw its really cool
In the wings, the surface to volume ratio is very high. Now consider it needs to be strong enough to withstand >100 psi and it will likely be not worth the extra added weight. Sorry to say
You can't keep a desired shape across wildly changing internal pressure unless it's made from very rigid (and very heavy) material. There could be a tubular inlay in the thick part of the wing, but it's volume to surface ratio and thus energy to weight ratio will be low.
Duuudeee, now imagine letting these parts produce as a universal kit for all the usual bottles out there and then .. kitefests and GIGANTIC AIRSHIPS MADE OF BOTTLES, PLEAZE!!
Always do the control surface check before every flight, its saves a lot of disasters. Try a folding prop and try more prop pitch so that you get thrust at lower revs. May or may not lead to a longer flight but worth a try. In flight the airflow allows a coarser prop than on the bench.
On the co2 point. I think 12 grams of co2 at standard atm conditions should take up ~6 liters. The co2 is liquid not a gas in those cartridges. Considering the drag difference between the 2 liter bottles you *may* be better off looking at the co2 idea again. Assuming you can regulate the pressure to something reasonable and give enough surface area to boil the co2 into gas.
If you manage to splice together more bottles you could have the tank be a structural component holding the tail. Also, some smooth fairings for the engine and/or pusher configuration would help a lot with drag I think. The former expectantly vince you are 3d printing I think it's a worthwhile investment of little additional weight
Not only is this plane amazing, but it looks extremely cool. The fact that that is because of design requirements, and not aesthetic reasons makes it even better. Amazing video as always!
Some observations: 1) I have used Opera since its early days, but I had to give up on it a few years ago because it kept getting buggier and more unreliable. After losing a large amount of data for the second time, I went back to Firefox and haven't looked back. 2) The reason that plastic model covering film exists is because in addition to being easier to use than paint, it's also stronger, lighter and smoother. Less drag and less weight. The additional paint you added was unnecessary and added weight. 3) If you look closely at how mainstream model wings are constructed, they have many small crosspieces running along the wings. Those are less structural than to force the covering film to maintain a shape much closer to the uniform desired airfoil. They are so small that they add little weight, but the benefit is much more significant. 4) Apparently you are unaware of prop savers. They use a rubber band (actually an O-ring) to hold on the prop. It may save some weight as well as keep your driveshafts or props from breaking every time you land.
The CO2 you typically find in cartridges/paintball tanks is generally stored as a liquid, therefore stored at a ~700x higher density than gas. It pulls heat from the atmosphere as it is used/expands, which is why you often see CO2 tanks (and propane tanks, for that matter) "frost up" when in heavy use. You'll likely find that you'd have greatly increased range if you were to run from a CO2 bottle.
Yes, even Google indicates that it is about 6 litres of CO2 at 1 atm and 0C for a 12-gram 21-ml cartridge. However, it will not surpass the bottle solution in terms of range.
I guess it would need a complete change of philosophy as the weight would be orders of magnitude higher. He would then need a way bigger and heavier motor, a larger frame and wings, etc...
I just wanna say huge congrats to such a long flight time! You put in so much time and effort optimizing every part of this plane and it definitely paid off!
Might I make a small suggestion of adding a fairing where the bottles are joined? A single piece of packing tape wrapped round the joint might make a great improvement in aerodynamics. More than the tape costs you in weight, at least.
Dude!! Congratulations! I’ve been watching over the years as you sharpen your knowledge and craftsmanship with this project. I’m literally at my house in Nome Alaska cheering you on. What an amazing success. That’s got to feel so great. I feel great and I’m just watching! Excited to see how far you end up taking this. You’ve really pushed this platform to levels I don’t know it’s ever been taken to. Keep on leading the charge Tom! Great work!
I reckon the added weight of having pressure-capable and air tight wings doubling down as reservoirs would be negated by the air capacity, and thus run time, those wings would provide. One of the reasons it struggles so much with wind it's because it is so light for its dimensions and drag, so adding weight for run time also has another benefit.
The shape is not conducive. To make an airfoil pressure vessel would require too much weight. To enclose a cylinder in the airfoil would probably be a waste of space. Instead, replacing the carbon tail spar with extended bottles for larger capacity and longer runtime would be easy and efficient.
A pressure vessel needs to have the smallest surface area possible to maximise it's efficiency and the wing shape would be one of the worst possible designs for that purpose. That's 120 lbs force on every square inch of the wings surface, don't forget and that looks like a lot of square inches to me and relatively not much volume! Imagine how much force there would be at the wing edges, trying to rip it apart! Curiosity may even tempt you to work it out, if you have the inclination. Actually, thinking about it, it would be equivalent to a teenager standing on every square inch inside the wing!
Thx a lot for the video, I'm from Brazil and 25 years ago I had this toy and I couldn't help but laugh out loud when I heard you've never seen you plane again after sending it into the air cause that almost happened to me. I was playing in a big football field near my home until got dark and I couldn't find the plane after the last trow. However on the next day I woke up really early and went to the place to wait for the sunrise and finally be able to find the plane. One of the weirdest sunrise I saw in my life.
This is so damn awesome... Could you potentially increase the flight time a tiny bit by using the exhaust of the engine as a tiny bit of thrust? As in, print the engine in such a way that the exhaust is redirected backwards?
Another video in this series, and it really was a great watch. Your engineering journey is so well presented and the satisfaction after achieving each optimisation is very contagious. Love your channel mate, keep on being awesome!
That was soooo impressive dude! That huge jump to over a minute, what a motivator! What I need is an air powered paramotor. I only need a short time power to take off over the sea and back to land for the thermals, plus there would be big air tank so I float if I go into the drink, perfect!
@@pauldickman4379 mass is going to be an issue, if the pellet weighs as much as the camera it can lift aloft then it might work. I am a bit concerned about plastic embrittlement under that temp, embrittlement and high pressures end up as bomb.
The issue is weight and ability to gasify dry ice (solid CO2) fast enough. Dry ice in air sublimates slowly as air its a good insulator in a closed space, unlike dry ice placed in water where circulation currents and the latent energy content of water speed up the state change process. Adding water would add weight, as need enough water to stop the dry ice at -78.5°C from freezing the water, which would greatly slowing melting of both. Note: a plastic bottle is just 42g (6:50), or 62g pressurized which holds over 8L of gas. A excess pressure regulator would also be require to avoid over pressurization. (as part of the weight budget)
You should also add landing gear so you aren’t always dealing with crash landings. Even skids on the ends of the wings should be good and help balance the plane’s weight ratio, allowing it to do better in the wind.
Brilliant! A friend of mine flies RC gliders, he uses surgical tubing and sting to launch the gliders. He uses natural thermal up drafts to lift the gliders to extend the flight times.
Tom, I am always impressed by the way you approach your projects and how you go about fabricating them. The latest air powered airplane is a great example of your thinking and fabrication skills. I look forward to all of your latest projects.
Man, using pressurized air to conquer air itself. Even for a hobby project, it's been a wild ride. I'm glad you had fun designing all this and thank you for documenting all of it. ❤
![[MV] A leap of faith...ความเชื่อใจครั้งสุดท้าย (From "Petrichor the series")](http://i.ytimg.com/vi/U1piZH2CNXA/mqdefault.jpg)
Hey a tip for your air storage: people that build water rockets have perfected splicing plastic bottles together for high pressure use. The channel US Water Rockets has some good videos about bottle splicing. You could save some weight and make larger chambers fairly easily.
Good to see you here!
I love it when cool engineering TH-camrs watch each other's videos!
Yeah I remember gluing 1.5L bottles together to make a 4.5L water rocket 12 years ago. 120psi is quite the limit though
That sounds like a good idea if it can take the pressure. There's a lot of weight in the bottom of the bottles and fasteners. Also, here in the US we have 3-liter soda bottles. Fuse a couple of those together and you've got 50% more capacity in probably less weight.
Air Command Rockets from Australia helped me massive through my water rocket project in 10th grade. They evolved from spliced bottles to carbon fiber air tanks over the years 😅
Dang! Love the perseverance and quality!
Don’t know why I’m surprised to see you here😂
i didn't expect the legend to be here
I love perseverance and ingenuity
LOL wow, this really IS a small world!
Yes. What he says. Perseverance
I love the split second thought at 15:12 where you almost seem to think "I can save it!"... Immediately followed by what seems to be ..."But it might cut my finger off?"
I really enjoyed this video! Well done sir.
Ye
It's your fault I haven't got smarter today
@@roflkopter That's on you, bucko!
The classic engineer's problem. "How much bodily harm am I willing to risk to save my creation?"
hey Destin, suprised to see you here but im very glad for it
Hi, something about your wings. Wings have the most drag at the ends because there the pressure between top and bottom is balanced and you get a whirl. For that reason the wings of a sailplane are long and get narrower to the ends.
In your design there is a problem in the center too because the wings aren't connected and you loose pressure in the middle too. I think, it will already help if you connect the wings with some packaging tape.
Best regards, Frank
🤩🤩
I'm pretty sure Tom knows about induced drag and aspect ratio, but the packing tape is an excellent idea
or perhaps a lightweight fairing
I agree Frank, make the wings a tad longer, but tapered, i would add another 30cm, 15 each side, Tail plane needs to be a built up structure, not solid, but remain a V, as that is light, perhaps fair in the front bottle to give a more aerodynamic, and less drag from the prop going backwards, and lastly, the center wing section needs fairing into the wing and Fuz, big time, you are inducing drag, and turbulence there
If you "loose" pressure, better fasten it …
Can I just say that I love everything about this series? The incremental efficiency gains, Tom's persistence, the planes themselves of course, and as a bonus, the lovely noise they make. I find it amazing that Tom keeps setting new goals and reaching them. Looking forward to the next one!
Combination of genetic and cultural history + passion = brilliance. Tom Stanton to the other 97% of all human inventions. Well done. Be proud
Thats an amazing flight! Well done!
You should try this sort of project out! Id love to watch it
Nice to see you here
Cool
*Kjempeflott* to see you here. 🙂
It's finally taking flight! Glad to see all that air engine testing coming to fruition, that's gotta feel good.
Here so people can't say first
@@nightmares100 by saying what you just did, you inadvertently made a comment just as insignificant as 'first'...
and so did I
I find it interesting that my favorite TH-cam creators consume each other's content, Even if it's not quite in their field.
LOOK ITS JEFF!!!
It's funny to see that the big TH-camrs consume each other's content :)
Nice to know you also like these air engines!
I imagine you feel the same way the Wright Brothers felt achieving their first 12-second flight. Very different problems for very different times, but you both breathe rare air.
the Wright brothers created something that was launched by a slingshot. The real inventor of the plane was Santos Dumont.
Or even 10 years before them Clement Ader
It took him six years to get this far. Without looking at the timeframe for the Wright brothers, i bet it's pretty sad considering the education and raw information available to this propped up wannabe.
And yes, i shit on him in that video too
pressurised
As an Engineer, i salute to your insane amount of passion you put in this airplane. It makes me smile uncontrollably to watch you progress on that project. This is nerdyness in its purest form. Thank you for your videos!
I can't wait to get a ride in one of those... to scale of course.
Engineers👋✌️
Agreed. I absolutely love this series. For that reason, I hope he never stops improving his design 🙏🏼 lol
hi sir i am need of project ideas in engineering physics with practical application . i am studying 1st year and with minimal or no electronics , could you suggest some if possible
Wow amazing.
Hi Tom, epic project!
I'm sure you've had lots of suggestions but I'll throw in mine anyway:
1. Replace the MG90S servos with standard SG90 servos, you don't need metal gears and this will save about 4g. You could also go smaller (GH-S37D) for a total saving of 15g and reduced size of the supporting structure.
2. Smaller LiPo pack.
3. Build up the tail surfaces from 3mm square balsa rather than sheet.
4. Taper the wings - better lift distribution and structural efficiency. Taper the spars to reflect the reduced bending moment as you move towards the tips. For tubular carbon you could glue increasingly smaller sections together, telescope style. You may need to add a few degrees of washout at the tips but this is easily done by twisting the wing to the desired angle and re-shrinking the film.
5. Lose the gap in the wing centre section and make the wing continuous. This is a big source of drag and is effectively halving your aspect ratio.
6. Add some rounded or tapered wing tips
7. Test some different props to find an optimum for this engine / airframe combination. This can make a big difference.
8. Higher pressure of course.
9. Don't use paint, it's heavier than you'd think and not needed under the film.
10. Use an iron rather than a heat gun to shrink the film. You'll have much better control and won't melt holes in it.
On your comparison to CO2 canisters, I'm not sure that's valid as the CO2 is compressed to liquid phase so it's not just a comparison of ideal gas volumes.
Great work though, I look forward to the next iteration.
NASA showed up!
Seriously.
I'm thinking tapering the wings may not help here. This plane flies super slowly, and is probably nearing the unfavourable range of Reynolds numbers, where the air starts becoming really sticky, and shortening the wing chord would exacerbate that. Perhaps adding a turbulator would help, you can try that on one wing first, which will let you easily gauge if it's improving performance (if it does, the plane will have a tendency to turn to the side with no turbulator).
CO2 transitioning a phase would make it way worse by cooling it down significantly, so if Tom's calculation is incorrect - it is incorrect in favor of air, not CO2.
Also, Tom, please make a prop saver - a small modification that fastens the prop with a small rubber band instead of screws. You will easily find it on the internets by googling "propsaver"
With regards to the CO2 cartridges:
A quick google says a 12 gram cartride (12 grams CO2, not considering weight of cartidge, I assume) has about 6L of CO2 at atmospheric pressure.
I think it might not be worth it.
It's slightly more weight, it's a part that has to be purchased *and* more strength needs to be added to the design to hold the higher pressure. Unless a larger CO2 bottle can be got easily and cheaply. Better CO2/bottle weight ratio.
Thinking about the rest of the design:
I think I would add a sleeve around the join of the two tanks to reduce drag.
Could also have two double-tanks side-by-side (4 total), have any less aerodynamic components between them and wrap the whole thing in the film. Add a few shapers and make it into a lifting body fuselage, while we're at it.
Do not use paint, it adds about as much weight as your balsa! Instead buy colored Oracover. It has same weight as clear!
Also: Look into using a folding propeller to avoid damage during landing. I am assuming power is low enough to let it fold on landing or that at least the blades will fold away upon hitting ground to avoid the snapping of motor.
The rpm of motor sounds like it speeds up as the plane reaches level flight which could mean pitch is too low. It shouldn't take much thrust to keep such a sleek wing in the air, and too low load on motor in flight will just use up air.
Seems like great points, at least to me.
Yeah thats why the space shuttle was orange
@@squidwardo7074 it... wasn't though?
@@dundeedideley1773they did paint it white at first but then realized it weighted a lot and would flake off and potentially impact the orbiter
@@dundeedideley1773They are talking about the big external tank holding the liquid oxygen & hydrogen for the main engines.
Tom you really have outdone yourself. As an engineer I really admire the design. Hats off it really is a beautiful plane. It’s been a great journey through all the different different versions and you’ve finally done it. I love how happy you are when you see it flying. I am very happy for you. Well done !!!
Love it. You could probably reduce drag significantly if you make a small fairing to cover the gap between the wing roots and allow the air to flow around the centre piece.
Agree. Packing tape would seal the gap just fine.
This is an excellent idea. There'll be all sorts of vortex stuff going on at the wing roots as it is.
+1 for this. Efficient airfoils are great, but whole aircraft L/D is the real-world answer.
Two tips. 1) I have been recycling PET diet coke bottles into printer filament for some time. My first step is to smooth out the iconic shape by pressurizing it to 70psi with a little water and heating it slowly in an oven. I've successfully shrunk, elongated in a form, and reformed the bottoms into a smooth dome. You may want to consider doing the same, giving you more volume at the same weight. Coca Cola published that their 2 liter bottles are rated for 150 psi, so if you only need 70 some experimentation might be warranted. I would love to see what you come up with. 2) Secondly, you could replace the tail rod with a pressurized fluorescent tube protector and make the plane a flying air tank. The water rocket people use them as pressure tanks as well, so there is a lot of data and technique to start with!
Best comment in this section
Awesome stuff, including recycling the bottles, what a great idea!
if the bottle was full of water before you put it in the oven and still completely filled afterwards, there would be no increase in volume
maybe the sides contracted a little?
Forming the air chamber into a lifting body, the wings can be shorter saving weight that way
@@marc_frank - Agreed, You can't fill it up, you just need a little water to protect bottle features from overheating. You could do the same with a wet cloth on the outside. For instance, if you get the threads of the bottle too hot the deform. Not a good thing if the bottle is at 70psi. The PET recycled filament people put a small amount of water in to use steam to expand the bottle if they don't have access to a compressor.
CO2 cartridges are actually almost an order of magnitude better than that because they are full of liquid CO2 and not gas. A 16 gram cartridge actually contains 9liters of gas instead of 1liter. 6:30
MassGas/density@1atm=(16g)/(1.77g/l)=9l
Easy to miss if you don't work with things like that often. Thanks for all the interesting videos and please keep them coming!
Yes! I was about to comment this. His comparison wasn't exactly fair.
It's also not just the volume of gas, but the starting pressure. Even if there was less gas, you need to calculate the energy released when expanding to atmospheric pressure.
A weather balloon stores even more air, but the pressure is so low that it can't do much useful work.
I just wrote the same as well.
And there are also 20g, 38g, 45g, 74g cartridges that will have much better ratio of the useful CO2 weight to the metal canister weight. And you're getting much more constant pressure, compared to that air bottle that drops from 8 atm to 1 atm.
There are problems with CO2 as well though - it will need a strong/heavy valve and you have to maintain the cartridge orientation, so you're not directly losing liquid through the valve.
@@JC-XL You also can't use the bottle as the fuselage due to the higher density - though this may be counteracted by the smaller cross section with respect to drag.
Ultimately CO2 engines might perform better but they don't really meet the intent of this challenge, given the whole point is to replicate the old Air Hogs toys.
I'd be interested to see a direct comparison between the Air Hogs and Tom's model. From my memory as a kid, they performed pretty well considering the small tank, stubby wings and blunt propeller.
@@JC-XL
It would be interesting to see propane used as the working gas. It has a vapour pressure low enough to be liquified in a soda bottle, and also be directly compatible with Tom's engines. I believe some paintball guns use it as a CO2 alternative.
While it is flammable, this shouldn't be too risky provided no ignition sources exist.
My little brother had the same air higs. We used to have so much fun with it. I was just randomly reminiscing about it to myself last night, remembering all the fun we used to have together. Crazy I come across this video the next day.
That’s just amazing Tom !
Omg how has no one replied to this comment yet?
YOOO, colab please
@@elvindiaz8475yessss
What exactly was amazing, could you please explain
No tomatoes harmed in the making of this vid
What a glorious sight! Proper long flight! It also sounds great, real old school prop noise.
Surprised to see you here.
@@j100j Two glorious youtubers
When are we getting the x-over episode 😊
Great video as always! Here's a tip to decrease the drag and increase the lift. At the moment you have two half wings joined together at the fuselage. This design generates some vortices (exactly like the wingtip vortices) in the inner part of the wing due to the gap between the two half wings. The vortices increase the drag and decrease the lift. Joining the wing in the middle would eliminate the vortices
in general the drag of the fuselage IMO hast the biggest potential for improvement. Add a streamlined nose, cover the part where the 2 bottles are joined together, cover the center wing section and add a tail fairing to the end of the rear bottle.
@@martinbrandmuller8272 Agree! There's a lot of possible improvement in the shape of the fuselage
You were so much more diplomatic than I would have been!
I hope Tom finds this thread. This is exactly what I wanted to comment as well. At the start of the video, he made a nod to aerodynamics and did do a really good job on the wings themselves, but at the end of the video he's back to talking about weight savings. A nice, clean bulbous nose and a smooth wing root area would absolutely do wonders.
yep, single wing over the top of the air tank using flaps would be even better.
This is so cool! You might want to implement a preflight checklist so excitement doesn't make you forget important details 😊
I never get over seeing the joy of a man who has built something that works but has little to no real purpose. All creator TH-camrs get it, you can always see the point it happens, right when they look at the camera and get that little smile. You know in their head they are like “it works! It actually fricken works!! I can’t believe it!”
Destin got it when he split a bullet, hawinglight got when he did his perfect Japanese sparklers, integza gets it all the time lol, styropyro got it with his recent car battery monstrosity and the list goes on and on
It might just have one good use never know
It's that Dr Frankenstein "It's alive!" moment... So satisfying to see.
It has little use now but it well may lead to something useful.
I would not mind travelling to work one day in a CompAir car, on the fuel that my fotovolt panels made during a previous day with a electric powered compressor... or a moped or something.
Start with a little thing having a bigger goal in mind, at the back of your head.
The styropyro car battery plasma cutter.. that was special lol
Yup. No one asked for the world’s fastest nikko dictator, but my god I was so happy to build it and drive it🤣
I can't get over how it sounds like a proper engine
I'm glad you documented it all because i couldn't stomach all this effort myself
Use an electric air compressor with a WATER SEPERATOR on the line going into the Plane tank. less water in the air will reduce the weight at the end of the flight and will make your air engine run ever so slightly better. The wings seem to be a bit overkill on strength. but man this had been awesome keep this going. I know you can do 2min for sure. Great Job.
there was no water in the tank in the flight tests, that was just for a pressure test
@@luckylmj I think they mean the humidity in the air
now I'm wondering is it possible to use a gas that is lighter than air, or would it turn into liquid under high pressure...and then would that even make much difference
@@mattblack6736a helium or hydrogen version would be pretty cool. I'm not sure how much weight you would save but it would be cool to see
@@luckylmj there was condensation in the air.
As a lowly software developer this is absolutely brilliant content. Happy to have youtube recommend this channel to me.
This is exactly what 3D printers were made for. WELL DONE!
3D Printing was first used for medical purposes as dental implants and custom prosthetics in the 1990s.
@lamarw7757 I mean miracle medical advances are great but plane go brrrr
wait. I thought 3D printers were made for printing 3D Benchys. Have I been doing this wrong?
@@lavachemist Keep printing those lil buddies
@@Mrcheesebumble What about printing glocks?
Tom, I'm sure someone else has mentioned this before - but the CO2 canister is not actually full of gas. It's full of liquified CO2, held under that pressure. The pressure is maintained until all of the liquid has boiled off, which gives an effective storage quite a lot larger than you might think looking at it as a simple compressed gas. :)
Yep, Tom said 21 mL expands to 1 L, but they are really 21 grams. 21 grams of CO2 at room temperature is more like 10 liters! Now, it would actually be quite cold, so that will decrease performance, and the cold itself will pose design challenges
@@themonkeyman2547 Maybe then add some "heating" elements :D
I hope he's seeing these comments about CO2 canisters. There's easily an interesting video discussing phase change and testing how the consistent pressure affects the air-engine's performance when actually flying (in terms of control). Not to mention tuning a suitable jet to meter the flow to the engine (and the cooling effect, which might not be that bad given the likely flow-rates). And, the cylinders come in a range of sizes (including much larger ones).
As I recall, Integza used a CO2 canister system, where an onboard Arduino controlled the release of CO2, using a bottle as the expansion chamber and maintaining a roughly consistent pressure inside the bottle.
Isn't it easier to use a deodorany bottle? Lmao I can imagine the plane leaving a perfume trail.
a crazy idea would be to make the wings pressurized to gain more air volume, maybe some internal tube like chamber along the wing to avoid pressurizing the actual film skin
Maybe the wings filled with helium to decrease the lift needed from the engine?
storing fuel in the wings is something actual airliners do, this isn't as crazy as you think
I know it's arbitrary but since it's a plane it wouldn't make sense to use lighter-than-air gases to generate lift, otherwise you could just make a blimp and easily beat the flight length record
I love this idea
Wouldnt it be better to replace the tail boom with a third bottle? Like Teslas "structural" battery pack.
You should look into lasercutting balsa for the flat parts (e.g. the 3d printed wing profiles and the tail flaps). It's often faster/cheaper than 3d printing, refuces plastic usage and could lead to lighter parts (though potentially also more brittle).
This series is my absolute favourite on TH-cam! Love your work Tom
I FELT AS EXITED AS IF I WAS THE ONE ENGINEERING THE PLANE. I've been following your air powered engine progress since the second version and when i saw this tumbnail I audiabply gasped. I can tell how much work you put into it and it reflects on the performance. I must be honest when I started watching your videos i thought they were kind of slow and a lower form of lame, but following your ups and downs made me love and appreciate the PROCESS. You're and amazing engineer and I feel lucky to celebrate your wins!!!! THANKS FOR THESE VIDEOS, PLEASE KEEP MAKUING US GASP WITH YOUR ACHIEVEMENTS
COMPLETELY agree with this comment, seeing that plane fly made me so damn happy
Same. It’s been a long time coming!
The fact that not all his videos end in success can be infuriating, but what I love about it is that it also shows the true nature of engineering. Once he finally gets to the goal it is so satisfying!
I've followed a few of your builds over the years. When you build a wing like this it is a good idea to add some washout. This is a slight twist in the wing so the the leading edge at the tip is at a slightly lower incidence than at thee root. What this does is make the wing more stable at stall speeds or higher angles of attack. When the wing root is at a stall angle, the tip will still be flying, so does not drop one wing tip and loose a lot of height etc. The nose will drop of course, but it makes for a more stable plane. With the airfoil, the centre of lift will change with the flying speed, shifting further back the faster you go, designing your motor to run at lower speeds with a bigger prop will be more efficient too. Until the prop stops at least...
Best engineering channel on YT. The fact that everything is made from scratch and even the engine is more or less your design makes these videos so good. I have that tinkerer in me but don't have the patience and perseverance to keep at it. It awesome to see how you just keep iterating year after year on the same thing.
You should enjoy James Bruton
he bought the propeller. I mean, your point still stands, but not "everything" was made from scratch.
No, and no. This guy is an idiot relative to most. You probably are just stuck on the child-pandering tactics he's better at than anything resembling engineering.
Not only does it fly very well, it even sounds like a real single prop plane! Awesome project!
imagine the technology the government actually has but pretends we need to pay for fuel...
@@ghostwhite1648bro the government isn't taking energy out of thin air, thermodynamics exists. This guy is expending tons of energy to get that air under pressure and then wasting even more to convert it back to mechanical power. He isn't taking anything out of thin air.
@@theairaccumulator7144 he’s not 30000 feet up.
@@theairaccumulator7144 we literally got people in outhouses fueling generators with wood gas and poop gas mang. Open ya fuggin eyes
@@ghostwhite1648 why would fuel be free? it takes a lot of resources to extract, refine and deliver. Please take your tin hat off.
Hi Tom ! I was following your updates for a while.
As an Air Hogs lover, I got into your journey to build your own air powered plane.
Just let me say that I'm really proud of you !!
1.22 minutes is more than a sucsess !! it is MARVELOUS !! UNBELIBABLE !!! BRILLIANT !!!
Your determination and your amzing skills are really impresive !!!
Congratulations from Buenos Aires, Argentina !!
And of course I'll be tuned to see the next flight !!
Many thanks Tom !! YOU DID IT 💪💪💪!!!
Hugs dude !!
HUGE congrats on the flight, this has been such a cool project!
One potential improvement I can think of is recycling some of the air from the expansion stroke of the motor to give the return stroke a small boost. It might even smooth out the impulse and lead to less rattling.
Great idea
I was thinking this will cause the piston to move back up above the exhaust hole before the pressure has dropped enough for the seal to retract.
But then I realized the seal responds to differential pressure...
So if anything you'd want to create a chamber below the piston where you dump gas to hasten pressure equalization which will break the seal, and then expediate the exhaust extraction, without actually introducing pumping losses on the powerstroke.
I think overall you'll have more benefits from larger exhaust port area,
and maybe you can harness some efficiency by nozzling the gas backwards for direct propulsion, or directing it at the crankshaft to accelerate it through bottom dead center. But then you're going to have to consult Alex from 2stroke stuffing about how to tune exhaust pulses I think 😅
I was also thinking along these lines. If the high pressure air was applied to the underside of the piston where the surface area was a little less and then using the spent air on the conventional side of the piston it could help balance the pressure losses.
@@thegregdavieschannel but if you're injecting pressurized air on the crank side you have a larger volume to fill and will probably have airleaks around the crankshaft or need seals to minimize losses. I think both will likely hurt the overall efficiency more than you'll be able to harness with recycled gas
@@VyantQuijt some steam engines used a larger secondary compounding cylinder to harness some of the residual energy.
It would be really neat to try and make that work in a single cylinder engine, but alternatively a twin cylinder engine might be the way forward.
This may be a crazy idea, but what if you had two bottle fuselages each with their own engine? kinda like a P38. Or maybe you could get four bottles together and fly it with the twin cylinder engines, which while less efficient should let you climb better and then you could glide for longer. Also the increased weight would make it handle wind better.
Yes, now that we have done the efficient stuff, lets have some fun and do some ridiculous stuff.
I'm so impressed by the level you reached after all those years, it's so satisfying to watch the evolution of your designs !
Keep going mate ! 💪
Assuming that your seals can take the extra pressure, or that you are able to create seals that can, if you wrap your bottles with some wire or tape, you could increase the maximum pressure that the bottles can withstand while not adding much weight.
I wish you could find some light yet strong tubes that could be used inside the wings to give it its rigidness but could also be pressurized so you have additional air capacity
Perhaps reforming the drink bottle into the shape of the wing?
In wing air is def the move here, all internal volume must be air storage.
@@jim_condit yeah im not sure how to do it where it can maintain a wing shape under pressure but it would be pretty cool to store air in the wings
@@index7787 yeah seems like the next move to get more air time
Build a wing of linked bottles? - sized to form the aerofoil? - "We'll need a bigger pump!" : )
Great evolution, Tom.
A few suggestions to add to what other people already said:
1 - splice multiple bottles together for added air volume while shaving some weight.
2 - As you add more bottles, you might want to consider using the bottles as a structural piece to hold the tail. It will save a bit in terms of size of the aircraft and might end up saving some weight too.
3 - For the balsa wood parts, you can probably make some more holes into it without affecting the structure too much. And since we are talking about shaving some grams, you might want check the weight the paint is adding.
Looking forward to the next video of the series. =)
Valid points
This has been such a fascinating and well made series. Multi-engine plane soon?
The way you bolted the bottles together was pretty genius.
Yep
Just echoing everyone else: it feels I've been watching you build these since forever ago and it's amazing to see how far you've brought it. Superb work.
If the tail feathers were stick-built like a typical (now considered old-school I suppose) balsa model, it would be lighter than a slab of balsa with lightening holes drilled in it. Love watching you develop this project, Tom!
My thoughts exactly. Same with the wings, and no need for the leaving edge sheeting at this type of plane. Nothing beats stick balsa when it comes to stiffness to weight ratio, maybe carbon fiber but not by much.
I have always thought that those 12 g CO2 capsules have 12 g of liquid CO2. In that case one 12 g CO2 capsule would have something like 6-7 liters of gas depending of air temperature and pressure.
You were thinking correct. He, for some reason, assumes it is just pressurized CO2 gas. At which would they could just as well have used air. The whole point of CO2 is that it is a liquid.
Congratulations love how excited you get when it worked
Engineers are just children playing with the world.
I love watching your progress over the years!
I've literally just paused at you pumping up the bottles "for the first time" I love your attention to detail and how much you cover each iteration.
This feels like the culmination of a real journey. Hope it goes miles
Excellent work.
YAY!!
So glad to see the accumulation of your research unfold into this marvelous flying machine! Great work!
My favourite part of the clip was honestly 14:20-14:31, the fact that Tom is so excited like a kid again is just so wholesome.
Watching you tackle each issue that comes up and continuing to improving it at the same time so satisfying. The finished product looks so cool and seeing it successfully fly for that long was impressive.
Id love to see if you could somehow use the wings as extra air tanks
I was thinking the same thing. Maybe there is some lightweight tubing that he could route through the holes... as long as it could hold pressure.
You probably need as round a shape as possible to maximize volume per unit surface area, since the surface needs to be strong and therefore heavy
@@brlamb5tubing would be heavy, very high surface area per volume.
airplanes today store fuel in their wings so it's cool to see this same idea pop up for this air powered plane! :D
I‘m guessing high pressure air tanks will make this unnecessarily complicated or would require molds and industrial equipment only a mass product could make cost efficient use of.
LETS GO TOM ive followed this series for years and always excited the moment i see a video. i’ve been following the engine series and knew something big was coming for some time
great work again
Congratulations, Tom!
It really is fun when something works and works well.
This is fantastic! As a fellow AirHogs-era kid, I'm so happy to see you succeed to such an amazing degree! Next up: 5 minutes!
If this doesn't become a kit you can buy I'll be so upset! Amazing work Tom as always!!
Through many life changes and moving across the country I have stopped making models as well as stopped flying. Videos like this make me wish I prioritized the hobby more as it brings me so much joy. You have devised some incredible solutions for this project and I am so glad to live vicariously through these videos! Very well done!!
Why did you stop your passion?
You continue to inspire me with every video! Not even my discipline of engineering but there's just something so satisfying about seeing you have these big and small breakthroughs. Counted the seconds it was flying like a bull rider on a bull. Awesome work Tom keep going!!!
Its feeling really good to see the development on this project. From one video to another you worked really really hard and finally made it. Congrats man.
To pressurise the entire wing might be worth a try, molding a "winglike plastic bottle" sort of. Maibe the "winglike plastic bottles" could be bigger and actually replace the bottles. Quite a job to test the weight/power ratio, but with 2 meters wingspan its a decent amount of volume that might be worth testing anyway. Nice work btw its really cool
Wow, the idea of using the wings _as_ bottles is quite interesting
In the wings, the surface to volume ratio is very high. Now consider it needs to be strong enough to withstand >100 psi and it will likely be not worth the extra added weight. Sorry to say
You can't keep a desired shape across wildly changing internal pressure unless it's made from very rigid (and very heavy) material.
There could be a tubular inlay in the thick part of the wing, but it's volume to surface ratio and thus energy to weight ratio will be low.
Duuudeee, now imagine letting these parts produce as a universal kit for all the usual bottles out there and then .. kitefests and GIGANTIC AIRSHIPS MADE OF BOTTLES, PLEAZE!!
imagine (DON'T PUSH HIM HE IS GETTING OLD)
What about an air powered model war? RC planes, water rockets, etc
@@Briaaanz absolutely lov it!!
Always do the control surface check before every flight, its saves a lot of disasters. Try a folding prop and try more prop pitch so that you get thrust at lower revs. May or may not lead to a longer flight but worth a try. In flight the airflow allows a coarser prop than on the bench.
On the co2 point. I think 12 grams of co2 at standard atm conditions should take up ~6 liters. The co2 is liquid not a gas in those cartridges. Considering the drag difference between the 2 liter bottles you *may* be better off looking at the co2 idea again. Assuming you can regulate the pressure to something reasonable and give enough surface area to boil the co2 into gas.
If you manage to splice together more bottles you could have the tank be a structural component holding the tail.
Also, some smooth fairings for the engine and/or pusher configuration would help a lot with drag I think. The former expectantly vince you are 3d printing I think it's a worthwhile investment of little additional weight
Not only is this plane amazing, but it looks extremely cool. The fact that that is because of design requirements, and not aesthetic reasons makes it even better. Amazing video as always!
Some observations:
1) I have used Opera since its early days, but I had to give up on it a few years ago because it kept getting buggier and more unreliable. After losing a large amount of data for the second time, I went back to Firefox and haven't looked back.
2) The reason that plastic model covering film exists is because in addition to being easier to use than paint, it's also stronger, lighter and smoother. Less drag and less weight. The additional paint you added was unnecessary and added weight.
3) If you look closely at how mainstream model wings are constructed, they have many small crosspieces running along the wings. Those are less structural than to force the covering film to maintain a shape much closer to the uniform desired airfoil. They are so small that they add little weight, but the benefit is much more significant.
4) Apparently you are unaware of prop savers. They use a rubber band (actually an O-ring) to hold on the prop. It may save some weight as well as keep your driveshafts or props from breaking every time you land.
The CO2 you typically find in cartridges/paintball tanks is generally stored as a liquid, therefore stored at a ~700x higher density than gas. It pulls heat from the atmosphere as it is used/expands, which is why you often see CO2 tanks (and propane tanks, for that matter) "frost up" when in heavy use.
You'll likely find that you'd have greatly increased range if you were to run from a CO2 bottle.
Yes, even Google indicates that it is about 6 litres of CO2 at 1 atm and 0C for a 12-gram 21-ml cartridge. However, it will not surpass the bottle solution in terms of range.
I guess it would need a complete change of philosophy as the weight would be orders of magnitude higher. He would then need a way bigger and heavier motor, a larger frame and wings, etc...
I just wanna say huge congrats to such a long flight time! You put in so much time and effort optimizing every part of this plane and it definitely paid off!
That was very impressive. You've come a long way since your first air powered RC place!
Might I make a small suggestion of adding a fairing where the bottles are joined? A single piece of packing tape wrapped round the joint might make a great improvement in aerodynamics. More than the tape costs you in weight, at least.
Dude!! Congratulations! I’ve been watching over the years as you sharpen your knowledge and craftsmanship with this project. I’m literally at my house in Nome Alaska cheering you on. What an amazing success. That’s got to feel so great. I feel great and I’m just watching! Excited to see how far you end up taking this. You’ve really pushed this platform to levels I don’t know it’s ever been taken to. Keep on leading the charge Tom! Great work!
Watching you slowly improve your engine design has been the most interesting part to me.
I reckon the added weight of having pressure-capable and air tight wings doubling down as reservoirs would be negated by the air capacity, and thus run time, those wings would provide.
One of the reasons it struggles so much with wind it's because it is so light for its dimensions and drag, so adding weight for run time also has another benefit.
Hey Tom, I've been watching your progress with air powered planes for quite some time, and I have to say THIS IS TREMENDOUS! CONGRATULATIONS!
Amazing seeing the continual progress you're making on these planes!
This suggestion may sound unconventional, but have you considered utilizing the wings as an air-tank?
In fact it sounds very conventional. Basically all passenger planes store their power source (fuel) in the wings.
You would have to completely change the design of the wings and they would have to be much heavier and stronger to hold 120 psi and hold their shape.
With a full Carbon fibre wing, he could do it.
The shape is not conducive. To make an airfoil pressure vessel would require too much weight. To enclose a cylinder in the airfoil would probably be a waste of space.
Instead, replacing the carbon tail spar with extended bottles for larger capacity and longer runtime would be easy and efficient.
A pressure vessel needs to have the smallest surface area possible to maximise it's efficiency and the wing shape would be one of the worst possible designs for that purpose. That's 120 lbs force on every square inch of the wings surface, don't forget and that looks like a lot of square inches to me and relatively not much volume! Imagine how much force there would be at the wing edges, trying to rip it apart! Curiosity may even tempt you to work it out, if you have the inclination. Actually, thinking about it, it would be equivalent to a teenager standing on every square inch inside the wing!
Thx a lot for the video, I'm from Brazil and 25 years ago I had this toy and I couldn't help but laugh out loud when I heard you've never seen you plane again after sending it into the air cause that almost happened to me. I was playing in a big football field near my home until got dark and I couldn't find the plane after the last trow. However on the next day I woke up really early and went to the place to wait for the sunrise and finally be able to find the plane. One of the weirdest sunrise I saw in my life.
Superb work, that is a brilliant flight time! At the speed you are flying I'd suggest the next wing has an aerofoil with a little bit of undercamber.
Congrats! It has been fun to watch the progress on this work. Can’t wait for the trans Atlantic flight in 16 years :)
This is so damn awesome...
Could you potentially increase the flight time a tiny bit by using the exhaust of the engine as a tiny bit of thrust? As in, print the engine in such a way that the exhaust is redirected backwards?
I love videos where somebody has an idea and makes it work without given up! Especially this one because I am an aviation enthusiast!
Great work, Tom, and congratulations on your achievement. Here's to longer times and more adventurous flights!
I honestly love how these sound. Nice job!
Imagine if Tom Stanton, Integza, and Peter Sripol all got together to build an airplane...
Air pressure powered jet plane!
No tomatoes in the world would any longer be safe!
Also, I would add the other two YT aeronautical guys NicholasRehm and Rctestflight. Tom uses NicholasRehm's controller.
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Another video in this series, and it really was a great watch. Your engineering journey is so well presented and the satisfaction after achieving each optimisation is very contagious. Love your channel mate, keep on being awesome!
Congrats Tom! It has been very enjoyable watching you incrementally improve your air powered craft over the past few years. Well done mate!
can u imagine if its possible using the wing itself as air chamber? great project keep going
That was soooo impressive dude! That huge jump to over a minute, what a motivator! What I need is an air powered paramotor. I only need a short time power to take off over the sea and back to land for the thermals, plus there would be big air tank so I float if I go into the drink, perfect!
I might speak for every single one of us that have filled your journey Tom, but damn I am so proud! Well done mate!
I am curious about the potential of powering the plane with a pellet of dry ice in the tank to extend range 🤔
Or lots of dry ice, and just make sure to release the pressure by flying it quickly before it becomes a bomb.
@@pauldickman4379 mass is going to be an issue, if the pellet weighs as much as the camera it can lift aloft then it might work.
I am a bit concerned about plastic embrittlement under that temp, embrittlement and high pressures end up as bomb.
I used to make water bottle bombs as a kid, just a little water and dry ice blows a water bottle in half
this is same as co2 cartridge, as it contains same dry Ice inside but when under pressure dry ice is in liquid form or supercritical fluid
The issue is weight and ability to gasify dry ice (solid CO2) fast enough.
Dry ice in air sublimates slowly as air its a good insulator in a closed space, unlike dry ice placed in water where circulation currents and the latent energy content of water speed up the state change process.
Adding water would add weight, as need enough water to stop the dry ice at -78.5°C from freezing the water, which would greatly slowing melting of both.
Note: a plastic bottle is just 42g (6:50), or 62g pressurized which holds over 8L of gas. A excess pressure regulator would also be require to avoid over pressurization. (as part of the weight budget)
You should also add landing gear so you aren’t always dealing with crash landings. Even skids on the ends of the wings should be good and help balance the plane’s weight ratio, allowing it to do better in the wind.
Brilliant! A friend of mine flies RC gliders, he uses surgical tubing and sting to launch the gliders. He uses natural thermal up drafts to lift the gliders to extend the flight times.
I've been watching this project since around 2020 and it's such a pleasure to see how far have you gotten! I'm genuinely glad for you!
Paint is pretty but is often heavy, I'd be interested in a weight difference between painted and not painted!
This is why the Space Shuttle ended up orange instead of white as on early flights.
Can't believe I've been watching you build air powered planes for 6 years. It's been a blast!!
Tom,
I am always impressed by the way you approach your projects and how you go about fabricating them. The latest air powered airplane is a great example of your thinking and fabrication skills. I look forward to all of your latest projects.
Man, using pressurized air to conquer air itself. Even for a hobby project, it's been a wild ride. I'm glad you had fun designing all this and thank you for documenting all of it. ❤