Issues to correct if you want to use this in a plane: 1. It weighs too much. Make it thinner, eliminate all of those bolts. 2. The shaft bearing is too large and bulky. Do you even need it? The rotor is made of Teflon which has low friction so maybe it can act directly as a bushing. Might help with sealing too. 3. Maybe go back to a 3 vane design now that you've changed the mechanism. 4. Experiment with different geometries for the exhaust port to exhaust faster and reduce back pressure. The vane is on an angle, so the exhaust port can match that angle across the whole vane length to the rotor along the swept area.
Check out the type of air seals used in jet engines. labyrinth seals. Also I forget what they are called. But there's little indented rings around mortar shells. Those help trap the gas without any friction with turbulence. Of course both jets and mortars have a lot of gas so leaks are less of a worry than people think. But there might be something worth stealing because they are both incredibly low friction.
Integza, about 23 years ago as my thesis project for Mechanical Engineering Technology, my friend and I designed a 4-bar mechanism that solved this problem. We called it the QRP or Quick Return Piston, because it had a 270 degree downstroke and a 90 degree upstroke. I still have the files and paper if you are interested.
I’m not an engineer or a designer of any sort, but I know how things work mechanically and build and repair things like this all the time. I just wanted to say that this was a great video. Humorous and engaging. I especially enjoyed how you displayed your errors along the way. From reading your comments and seeing how so much people seem to know more than you about something you clearly was experimenting with, I think you it’s safe to call any comment a win. You got all these know it alls to watch from beginning to end. Keep up the great work. Can’t wait for more! Aloha!
So here we go. 1. With only 2 vanes, the engine is pulsing. 3 or 4 would increase the surface area to catch the air. 2. The ball bearing is overkill, make the case tight around the shaft. Experiment with o rings or a ledge. 3. If you're regulating the pressure to 2 bar, then you can reduce the thickness and weight of the housing. 4. Instead of vanes, you could use disks. Alot like a tesla engine just small enough to save weight. 5. Rotating mass will be your friend for extended run times due to the light weight. Attaching the propeller with a larger single bolt will help the fluctuation in rotational speed. 6. Inceasing the size of the exhaust port would allow the air to easily escape, increasing the pressure difference on the inlet which would increasing torque. All in all, a really interesting build and your build process is really relatable. Keep this series up until you battle Tom for air superiority!
@@-danR The inlet Port should be putt more into an angel. Maybe 10° more degree towards the roation and three flaps. So the Air pressure is directed to the Flaps instead of "filling" the room.
You should consider increasing the number of flaps from 2 to 3, and either enlarge or add another exhaust port at a 120° angle to prevent compression. The operating cycle of your engine should follow these stages: inflation (at constant pressure), expansion (until atmospheric pressure is reached), and exhaust (again at constant pressure). In your current design, the expansion stage is inadequate, followed by a compression phase. This increases the overall pressure and wastes a significant amount of energy. The exhaust pressure should be equal to atmospheric pressure, so it might be worth adjusting the intake pressure accordingly. Finally, it’s advisable to resize the model to match the required output power.
Perhaps I wasn't clear enough. In the 3-flap model, the first two cycles perfectly align at 120°, and in order for the third cycle to also match, the engine would need to allow for an exhaust phase during the entire 120°. This could be achieved with a large exhaust port throughout the entire stroke, or at least two ports-one at the beginning and another at the end of those 120°. If necessary, an additional flap could be added, as more flaps increase the expansion ratio. In the 2-flap model, air is injected for 180°, and expansion occurs only for 90°, resulting in a much lower expansion. For 2 bars of pressure, a 3-flap configuration is optimal
You are absolutely right about the harmful compression. The exhaust should be at 180 + 180/flaps degrees from the input. However, it seems kind of wasteful to let that portion of the rotation do nothing. I think if he has already abandoned the use of mechanical sealing and switched to flaps, he can make the chamber oval-shaped. This way, the expansion phase can be longer than the narrowing phase, with more degrees of expansion. Theoretically, it does not make any difference, but it feels like a more gradual expansion would be better.
This is what i was going to suggest, But i would go as far as going to 4, Since the area of efficient expansion will be partially overlapping the exhaust with 2 or 3.
@@Joy-R-Us The maximum expansion zone occurs with the flap set at 180° + (180°/number of flaps). As the number of flaps increases, the final expansion point shifts backward. Therefore, the exhaust port must be extended to that point to avoid compression, which also increases the expansion ratio. It is likely that 4 flaps are optimal for 2 bar pressure, but with improved efficiency, it may be possible to reduce the feed pressure and extend the flight time with 3 flaps.
First-time viewer and ME myself. I have to give you props on showing how engineers make design ideas a reality and how we troubleshoot along the way. One tip would be to slow down the math calculation just enough (at least 2 secs) for people to pause the video and absorb the physics. Otherwise, you are killing it.
I really like the flappy engine, because it was the 1st design that moved away from traditional pneumatic air motors used in air tools for the last century. Probably due to wear rates, but still, for the intended use it's a really well thought out work around towards efficiency, power and weight.
Hey, I came up with two ideas for this engine that might improve it (or make it worse): -The first idea is to make the outer circle in the chamber into an ellipse and place the inner circle at the center (making the system symmetrical). Additionally, doubling the number of holes for air intake might help, but the intake holes would need to be made even smaller. -The second idea (probably more interesting) is, rather than having holes that let air exit to the outside pressure, to connect them to a smaller bottle (or capsule) where the pressure is lower than the outside. This could create a situation where we control the airflow and generate additional force in the same direction. I’m fully aware that this makes the system much more complicated and harder to run, but I think it could lead to even more interesting results. By the way, I really like your videos!
@@aflac82 Teflon is a brand name, it's actually just PTFE. A compound that was used in this material was carcinogenic and got banned. Your non-stick pan still has a 'teflon' coating.
Since the flappy engine has so much less friction, have you considered going back to a three vane or four vane, that way more of the pressure that’s coming in has a smaller expansion area before the next vane kicks in, I may not be explaining this correctly but a third or fourth vane should give it more torque and or speed, just note this is an idea before the end of the video, timestamp is 18:37…never mind I just realized the total length of the video😂
Also trash the bearings, instead make the rotor with the “shaft” built in and in the main block just have a blind hole and do the same on the front cap. That drops the leak area plus with it being made from PTFE, shouldn’t be much friction!!! {-o-} diagram for example!! Love your channel, and Tomatoes are totally gross!
@@studiowilds9879the mechanical strength and low friction in bearings is almost nessesary in this situation, any other mounting will be too much friction and too weak, but if he would add a simmering to make it airtight, it would probably work better, but more flaps could maybe be a trick as you explain above
I should have read the comment’s 🤣 though I’m not sure how 4 flaps would work because 3 seems to be the magic number. It would be wild to see him try this….with and without lubrication. Either way, great minds think a like and I love your comment!
A way to eliminate some of the leakage as seen at 12:40 can be using sealed/shielded ball bearings or even better, fluid shield bearings! not only it'll eliminate the bearing leaks, it'll help the engine run smoother since the bearings are constantly lubricated.
The vanes (around 5:45) are being pressed back into the core of the rotor because there's a huge pressure differential between the outside of the rotor and the inside. It's air pressure that is forcing your vanes in. When the air pressure that leaks past the vane, into the center of the rotor, and out of the engine has dropped enough, centripetal force can overcome it and the vane closes again.
It would be interesting if there was a passage in the rotor where its entry went from the pressurized zone, through the rotor, and into the bottom of the vanes' "cylinders" so that the pressure is equalized. Alternatively the centripetal force could still overpower the pressure differential if the diameter was made larger or the vanes heavier (v^2/r). Mechanical engineer here. I'd be happy to provide sketches of either!
Use less diameter bearings to reduce the area of leakage in them. Also, it's better to have more volume of the engine cuz it improves the ratio volume/leakage.
I believe if you have more volume in the engine the running time will lower because air in the bottle is still the same so % of air that is wasted is higher
Or 0 ball bearings, since it only runs for a couple minutes he could just use teflon sleeve bearings/bushings with some light oil or grease. Also if he was to change the drive shaft to steel he could use a much smaller diameter which would result in lower leakage around the output.
I've scrolled a lot of comments and haven't seen this one yet: The two-vane design might have more potential with a small spring in addition to the rod - because the shaft is off center in the chamber, when the rod is vertical the secant line is the full length of the diameter, but at any other angle it's shorter, so either the vanes are lifting off of the rod at the full diameter or you're experiencing leakage past the extended vane into the exhaust side. Great video, it's fun to see the entire trial and error design process!
From what I'm seeing, you're putting more air through the stuff and never letting it out, that's why you get leaks. There are 2 chambers separated by the vanes. The first one gets the air intake and it's volume grows, that's fine. The second one has a somewhat constant air quantity, but it's volume shrinks, it builds up pressure, resists the movement and ultimately generates the leaks. Add an outlet hole in this chamber. If i'm right you might get a better seal, and less resistance from the outlet chamber.
@@orestdubay6508 Yep my 50 year old marine engine used a vane cooling-water pump with "compliant" rubber impeller, It's a far older design than you think. Making it low friction is the challenge here though.
Given the friction, what about making the flaps replaceable tabs that lock in with a key fit, but doesn’t add extra leaks? After enough run time the flaps would wear down like apex seals do.
Several improvements are possible: 1. Drop huge 2 psi valve and resort to using a 3D printed reed valve integrated directly in the motor. Why? Weight. You need the lightest design to successfully fly for a long flight. 2. Drop the metal bearing and simply make a PTFE centre shaft as part of your motor redesign. Both weight and less friction will result plus less leakage. 3. Your use of PTFE is great to reduce friction and also deal with engine heat, but you still need some lubricant to deal with the micro leakage. I suggest providing a amount of light synthetic oil via the central shaft where you made the bearing replacement. The centripetal force will dispurse the drop sealing not only the central shaft and lubricating it but will fly to the outside of your leafs and then seal there to provide seal plus lubrication to the leafs. You thus solve both leakage issues. On a final note, the Tesla Turbine concept which you do not mention (since it applies to fluids not gases) could draw inspiration by potentially using the exhaust gas the the outer edge to a perpendicular disc adjacent to the motor with the disc dimpled with half clam shaped dimples to catch the air but using a logarithmic sizing of reduced clam size as you work to the centre that would be exhaust port. Despite air not acting with the viscosity of liquid as Tesla design, the clam dimples could assist to additional acceleration of the central shaft of the motor. Of course such fabrication was impossible in Tesla days but with a 3D SLA printer it is. The only downside is additional weight to add this and also size since the larger diameter disc provides greater efficiency in the Tesla design. Since you wish to fly, just stick with the original 3 points. FYI - a recall around 2008 when a company out of India called Tata was proposing using air as the new fuel. They did make a prototype car but I think it only went 30km/h and so for small city driving. No clue on their engine design but I always liked the idea of air as the fuel with the exhaust as the air that went in! The question of how best to compress it likely created the additional complexity that we never saw it materialize.
1: that pressure reduction value weights 10x more than the motor itself. A reed valve sets a minimum pressure not a max. How would that work? TATA discovered that the air in India was too dirty and clogged the compressed air engine. !!
@@stephencaparelli7733 I felt so smart when he said that! Maybe I can be an aeronautical engineer after all! But in actuality, I work at IKEA, and yeah, no.
I have worked with fuel pumpsets that have air eliminators that work in a similar way,they remove air and prime the pump set. It has spring loaded graphite carbon fins that spin in a cylinder,the carbon also gets deposited to the cylinder wall which helps reduce friction and maintain a good seal. 👍🏻
That confused me... I'm not understanding how they were both always in contact with the outer cylinder, when they were spinning in an offset radius; was there a spring in that shaft?
@@userzero9259 it doesn't matter that it was offset, all the matters was that they stay the same distance. if you're good at visualizing, imagine focusing on just the rod. it doesn't matter what else is rotating around it, it's just getting pushed back and forth from the pivot's POV
I LOVE the childlike naiveness of youtube comment section. It's not like pneumatic engines have been practically solved for years if not decades and literally anything seen in this video isn't new nor unkown to the content creator beforehand. He's not even that good at pretending coming up with new solutions or being surprised at things like..... not using any lubricant, LMAO.
This is awesome. I love this little flappy engine; I think you have landed on what could be the new gold standard design. Please check the sealing on the piston's axial direction. If you machine annular flap seals into both piston faces, remember that the propeller is pulling the piston towards the front, so the seals on the back face of the piston will have more clearance. For even better sealing and less friction, you could make the entire expansion chamber PTFE, using the resin housing for structural support. Or just machine a grove in the housings for PTFE o-rings. Finally, your bearing isn't the best one for an airplane. You need a thrust bearing in the front of the engine and a sealed bearing on the rear. The front bearing and engine housing is taking all the load of pulling the airplane forward.
The pain of air engines...it's so addicting hah! Best way to reduce friction of the rotor further is to reduce contact area against the housing faces. So just have a small lip around the whole edge (plus the whole flap of course). Less area means less friction so you can have a tighter fit for less air loss and same friction. Or same air leakage with less friction. Really clever design, how long do those flaps last before fatigue failure?
Contact area isnt really important for friction. You have to reduce the normal force and the coefficent of friction. With the rotor fixed on the ball bearing and effectivly flying in the housing,giving the rotor - housing clearance a thight fit, you could increase the almost contact area there and smear it with thick grease to seal it.
@@AA-rc6ob Should be less. Any point of contact is an opportunity for leakage. The force at any point of contact is directly proportional to the pressure - it doesn't matter how large of an area there is. However, the amount that manages to sneak through per area also depends on the pressure, so if there's more area, there's more total flow through that area. This is why his smaller nozzle provides longer runtime but less torque - it's the same force coming out per area of the nozzle but there's less area so less total flow.
The whole point of a tesla turbine is to blow air directly on a set of discs, so unless you mean "scrap everything you were doing to make a Tesla Turbine instead", the mechanism he's using inside is taking up the exact spot he needs to make a turbine with.
Given the leakage occurs through the bearing, the bearing itself could be extracted from the main piece. It would be kept aligned to the rotation center axis, but only sustaining a center rod with minimal radius to be sealed against the pressure chamber.
This video is amazing. I am in school for mechanical engineering and I want to go into the aerospace industry. This stuff inspires me so much! Thank you!
Man, this air rotary engine idea is crazy! Imagine using a nautilus spiral for the chambers resulting in smooth airflow, less turbulence, and max efficiency. Pair that with interlocking rotors, kinda like layers in a satellite design, and you’ve got continuous compression with almost no stress on individual parts. Oh, and dynamic balancing? Add some flywheels or counterweights to keep it running steady even at high RPMs. You could even go modular by stacking rotary layers like pancakes for more power and redundancy. And instead of just air, tweak the design for steam or gas mixtures too. Ducted pathways with adjustable vanes? Boom, variable compression ratios on the fly. Seal everything tight with optimized D:d ratios for minimal air leakage. This thing could integrate planetary gears straight to a generator or drivetrain, no problem. Test it out in CAD first to get those nautilus chambers airflow-optimized. Legit hybrid engine potential here!
I think you should add a gear train to the engine. Also a teardrop exhaust port would probably help exhaust pressure to increase overall preference. You could use a seal or an o-ring around the shaft to prevent loss of air pressure.
Quick, simple, and requiring no major container changes: Increase the number of flaps. I KNOW you reduced the VANES to 2 to reduce leakage; however, flaps are different because the pressure increases the seal. Thus, more vanes means more torque AND without sacrificng sealing. NOTE: I am NOT suggesting going from 2 to 3; rather I AM suggesting seeking a sweet spot which might be 3,4,5, etc. to find the optimum between the net increase in friction with the net decrease in leakage. You MAY need to simultaneously seek a sweet spot with regard to pressure as well. Hope this helps. BTW, I love your presentation style.
i think it very much depends on how much friction each vane/flap causes, if there are two pressurised cavities (implying 3 vanes/flaps under some pressure) then the mid vane has pressure on both sides, albeit that the pressure in the cavity nearer the inlet ought to be greater than the cavity about to exhaust.
It's not that simple. If you have too many the airflow into the chamber gets cut off too soon. Most energy is probably extracted between 30 and 60 degrees after the inlet. With two flaps the movement after 60 is not helping much. With four or more you are not maintaining full supply pressure throughout the productive part of the cycle. It could be calculated more rigorously but my gut feeling is that 3 may be the optimum. You are right, his reason for moving to 2 has gone, he need more flaps.
@@nomdefamille4807 Thank you for your well considered response. In my mind I pictured sort of a water wheel -- but you may well be correct. I am not much of an engineer; I have always taken the million monkeys approach -- admittedly, more tortoise than hare; but it usually works in the end.😀
@@nomdefamille4807 Thank you for your insight. You are obviously a much better engineer than old kitchen chemist me. I had visions of a sort of water wheel efffect; but, that just might be the amateur in me. I still think something along those lines might be worth a shot. Who knows; even if it fails, it just might provide some iterative inspiration. 😀
@@tuberroot1112 FYI Commercial vane motors can have up to 10 vanes. It appears to be a judgement about lower friction vs lower internal leakage and RPM. As long as the vane still has space to expand outwards then the air can continue to expand. Given the inner rotor is offset from the outer, the rotor can rotate 180º and continue to expand.
I LOVE LOVE LOVE that you took on this challenge. The pneumatic engine removes combustion dangers, allowing everyone to try new ideas on one of the most useful components of the modern world. Converting stored energy into mechanical rotational energy. Years could be spent tinkering with pneumatic engine designs. Its incredible the varied possibilities that exist, things that have never been thought up just waiting to be discovered. My favorite video EVER that you've created. Except needs more exploding "Tom"atoes.
I must say I'm quite worried about you cutting through PTFE/Teflon, and even just using it. Broken down PTFE is basically PFAS, aka. forever chemicals, where little amounts cause cancer eventually since they might never leave the body, and never leave the envrionment. I'd just stay away from those, using PET, grease, parrafin-based wax, or other alternatives. If you want to learn more, just search for PFAS, and/or watch the movie "Dark Waters".
Hello, in order to reduce leaks between the transparent plate and the rotor, you could install a series of 2 or 3 baffles, they are used in applications with very high rotation speed and high pressure. I remember this passage from my engineering classes. With the tolerances of your printer this might be possible. (sorry my english is bad it's not my native language) Edit : There is no friction with this solution, because the two parts do not touch.
I was thinking some matched up oil grooves for the same leakage points. since it's a short duration doesn't matter much but needs sealed. and a frigging o ring around the main body and clear plate. once the spinny bits are better sealed, that body is going to be the next spot.
I just randomly happened to have this video pop up. I know nothing about air engines. But, this comment section, which I see as a super nerdathon... Is probably one of the coolest things ever, seeing everyone providing so much help towards creating perfection. I wish I could be like all of you.
As an engineer I've seen something similar in a marine application here's what I suggest. Use a 4° reverse vein use your pushrod design. Use graphite powder dry for a lubricant and gap filler. Your central peace should be two parts to clamshell against the veins and the pushrod unless you can get tight fitting as single piece. You may even be able to go to a three vein 2° reverse angle using a cam style to move the pins in a direction to keep the veins close to the outer shell. And you could then use a nitrite seal or similar automotive style seal on the output shafts of your rotary vein. That would minimize your parts your escape portions if you do the tight tolerance thing again with the seal it would keep everything much tighter with less friction minimizing your parts and less air gap
The 2-part clamshell to get a tight fit around the sliding vanes is a good idea in theory. But that gap is already eliminated by being the solid attachment point of the flaps.
I LOVE the video and your sense of humor. The single greatest problem with the flapper vanes is that fatigue will cause them to break very shortly. If you could design a type of hinge that would eliminate the flexing and then make that leak-proof, THAT would be pretty cool. As for Tomatoes; have you NEVER tasted a BLT or Bacon, Lettuce, Tomato Sandwich made with White or Sourdough bread and Hellman's mayonnaise? Obviously not. If you had, you would think of that as ambrosia; The Food of The gods.
Ditch the bearing, use straight teflon on teflon. Machine the rear housing with the shaft your rotor sits on (rotor axle and rear housing is one piece) axial drill from the back into the shaft portion, not all the way through, and then drill a radial hole on the shaft. This will be your air inlet. Now on the rotor, machine it with the propeller shaft (as one piece) then drill 2 axial holes (on the rotor) to the center in a way that times the air inlet at the correct spot in the rotation of the rotor. (rotor shaft hole placement will be tougher to time) I would suggest a taper fitments at the base of the rotor shaft, and base of the propeller shaft, this will aide with thrust sealing caused by air pressure and the thrust created by the propeller. The blow by air (should be minimal) will help reduce friction and cool the teflon on teflon bearing. Obviously, you will need matching tapers on the rotor shaft to rotor and the rotor to outside cover. This design, in theory, will reduce friction and eliminate gaps (only 3 pieces now), reducing your escape losses. The hole on hole setup (when the air inlet hole on the rotors shaft lines up with the hole in the rotor) will act as the regulator, much like that checkball on the other guys motor.
@DavidMulligan yes, but a bit more complicated. Using the air pressure to act as a cushion between the teflon pieces. Also lessens the amount of pieces, making less areas for loss.
Yeah he went dual veins because of sealing and springs and kept it as he went to flaps but with the flap designs there is no reason to keep only two veins. Not sure if more veins will help getting better results but it should be tested for sure.
@@gg4760-k5n Three vanes will probably help, because as-is air inflow can leak over the back of the rotor to reach the exhaust and lose pressure. Three sections will allow a filling section, a power section, and an exhausting section.
more longer, thinner flaps makes for turbine, but that'd be heavier and brittle - engine that works till first touchdown? 2. Do we really need to sal friction of teflon against teflon? Doubt.
Simply fantastic work! The pressure regulator acts like a restriction in the feeding line. The pressure drop is wasted energy (deltaP X Flow). You can compensate the pressure variation (and, thus, torque) changing the excentricity of the engine Higher the excentricity, higher the torque for the same air pressure. Note that, initially, when you have higher pressure,you will need a smaller excentricity to generate the needed torque. Lower excentricity leads to lower flow, thus reducing compressed air consumption. When the air pressure is low, at the end, the excentricity is increased, sustaining the needed torque for longer. This can be achieved with a movable engine housing, actuated by the inlet pressure Look for "variable displacement vane pump" Greetings from Brazil
Yeah, I noticed the waste of energy in the pressure regulator as well. You reduce the pressure, but the amount of air molecules that are in the bottles and can go into the engine stays the same. But wouldn't an engine with zero eccentricity waste air molecules instead? Yes, you get less force, but the air coming into the chamber is still 2 bars (or actually even more), and the "input cutoff size" of the chamber (the size at the point when the input port gets cut off) is basically identical to the "input cutoff size" at maximum eccentricity. And any time the chamber reaches the exit port, the pressure in it is still dumped from X bars above ambient to ambient pressure, even with zero eccentricity. I have a feeling that variable *eccentricity* only works for pumps. For engines, you probably want to keep *maximum eccentricity at all times,* but "vary the position of the input port". With high pressure, you want to input port right next to the "apex" (where the rotor touches the housing), since the chamber is smallest there. But for lower pressures you'll want the input port moved to (or a secondary input port opened at) 90° from that position, where the volume change of the chamber is highest. And obviously, varying the position of the input port with respect to the point where the rotor touches the housing can also be achieved by shifting the rotor axis, so that the point where it touches the housing moves with respect to the (fixed) input port.
Not sure about the energy loss. The number of molecules is the same but the volume of air will be larger. Energy loss would develop heat (the energy has to go somewhere) which doesn't happen in a pressure reducer.
That's awesome! Your engine works really well! For me there were 3 separate moments that were like inspired: Firstly the flappy engine is obviously great. When I saw the thumbnail I stopped scrolling just to look at it for a while, and once I figured out what it was doing I was like "oh shit! That's very cool and elegant!" And then second was when you connected the vains together. That was brilliant! And so simple! And finally when you made the parts fit exactly by using the grinding paste! That was really clever and I really liked it! And it was really cool how you said how you got the idea from learning how those ladies made those camera pieces fit together. So yeah not that you should be taking cues from me on when to feel good about yourself, but I was really impressed by this video! And thank you because I enjoyed watching it.
3 design changes you might want to consider: 1. At 4:15 you throttled the engine via friction by reducing the nozzle size. Instead, consider adjusting the torque demand of your propeller (diameter, pitch) if you want to trade run time against power. 2. The rod idea at 11:23 is geometrically flawed: when it is aligned with both the centre of the rotor and the centre of the hub, it needs to be the diameter of the hub. However, at all other angles (especially perpendicular to this direction), it needs to be slightly shorter, as it no longer passes through the centre of the hub. Of course, this is no longer an issue with your flap design. 3. Perhaps you could add a flexible lip to the edges of your rotor that presses against the casing - through pretension and also through air pressure.
@@lih3391 but when the rod is in 0 deg (vertical) it goes via the center of the housing. When rod is in 90deg (horizontal) it goes through the center of the piston only which is offset - so shorter distance wall - center - wall.
18:32 I would think that combining your flap design with your vane design would be best. Like a vane that has a flap sticking out of it, like a y ... you also might consider an o-ring seal around the core of the rotor, against the walls of the chamber. to prevent air from leaking that direction.
If you also put the flappy flap on the side the engine would have an even better seal. Also, test again with 3 or more flapy's at a lower pressure. Maybe you can increase the runtime even longer.
Great video! I wanna see you build a rotary subwoofer, test its ability to move air, and create very low frequencies. I heard they can be pretty dangerous to use indoors because if you accidentally find resonance it can break walls, windows and stuff.
Hi Integza, Phi here! I have a bit of experience with vane motors and vacuums pumps. It looks to me like you can solve a bit of your tolerance problems by making your rotor larger, and the vanes shorter, in your flappy motor design. It will give them less opportunity to flex under the air pressure, and allow for you to run it faster or at least more efficiently. For the vane design on the other, narrower vanes are better, but the cavities should be sized such that there are extremely tight tolerances, and when the vane is fully extended there should be about 2/3 of the vane left in the gland, otherwise friction will try to drag it out of its space, causing more friction, and eventually self destruction. Gaskets and rotary shaft seals are grand!!! Three vanes are better than two in all regards. Cheers!!!
★ use a roller wheeled tip on the end of the rod's tips, carve a matching groove around the ring, this will not only increase the life of the engine, but it will also reduce heat less drag and improves performance and its still air tight. it might even reduce noise 👌
Please make a version 2 of your turbo jet engine that will run for longer , it was one of ur best videos, I too felt the joy when it started working , plsss.
My favourite video of yours. It's just one good idea after the other. Good luck kicking Tom Stanton's 🍅 Quickest/easiest fixes: 1. 3D-printed flap mechanism + teflon housing. CNC cutouts around flaps increase the volume of air wasted. Maximize pressure differential vs volume per compartment. 2. Print versions with different amounts of flaps. Finding the correct amount in theory will take forever. Just print versions with 2 up to 5(?) flaps and see what's most efficient. No math needed. 3. Use a liquid, plastic-compliant lubricant. It's basically a free sealing agent. 4. Ball bearing in the center really makes air leakage too easy. Teflon center shaft and a lubed bushing would have just as little friction and be much easier to seal. 5. The front and back wall need to keep the air in the flap compartments. Look up a "labyrinth seal". Perfect for rotating designs, easy to implement, basically zero friction. Add the lubricant, boom, got a great seal. 6. Where is your outlet? It wasn't entirely clear in the video. Just make sure the air escapes quickly after the halfway point, otherwise the engine is working against itself. 7. Housing with a nautilus shell shape, but with a very smooth transition, so it doesn't wreck the flaps or cause them to catch. Then you can use almost the full rotation for expansion. Adjust outlet position accordingly. 8. Make sure the back wall is stiff enough to make the deformation due to axial force from the prop negligible. Otherwise sealing the flaps will be even harder. Those are all the easy ones I can think of. Edit because I was being dumb.
My background is industrial maintenance. My recommendations are simple. 1: Enlarge the end of the housing to accommodate a lip seal on the shaft. 2: Put the on/off valve between the pressure regulator and the motor. Air flow does act funny sometimes. 3: Enlarge the housing to a pill shape and supply air to the second chamber. You may have to reduce the size of the restricted orifice going into the motor. Just some ideas.
I know I'm too old for a Make-A-Wish, but I hope fate lets us hangout within the next 18-24 months. Making a project with you is definitely on my bucket list. You seem like a genuine and funny person. Both of which I could really use right now.
To improve this wonderful tiny thing: 1. Center the air intake as much as possible for the airflow to hit the flaps (it's not about max torque, but about the air efficiently pushing them) 2. Make the flaps into a pelton turbine shape: if it's efficient for water, it's probably great for air too! 3. Get a bearing with a rubber side: a lot of pain was leaking through the bearing! 4. as @naasking was saying, experiment with 3-flap design and try to reduce back pressure 5. find the optimal width: with eiter software or a couple of prototypes, surely there is an optimal width that maximizes torque without killing rpm. I hope this helps! Much love from Italy!
the traditional pelton wheel gets its advantage over the venerable water wheel by providing a course for the fluid to reverse direction in to an "unconfined space", so for that aspect the air needs to leak out. here i think he needs the torque of the "rotary piston". if he is currently running for 3 minutes against a need for 2 then he could open up the inlet nozzle slightly and increase the depth of the rotor/ motor. he really should try and dump the regulator, the assembly would better use the stored energy if it could withstand peak soda bottle pressure. and in terms of flight performance anything to reduce weight, as all others have pointed out.
@@dziubo1 I suggest you go and have a conversation with Mr Bernoulli and ask him to explain his gas principle to you, then you might be able to answer your own question.
You should now try 3 or 4 flaps now. Bear in mind the Teflon fatigue and that it may not last too many open close movements. As well to ensure min air loss you may try some tiny soft springs, just to be sure they're always at max open. Optimize the engine before going smaller or changing the shaft.. Nice project! Keep on doing what you're doing as is great!
add a ball valve before injection, reduce chamber size, make a spiral to open and close the ball valve only when you need it for the amount of air needed to achieve the rotation you need.
@integza 11:23 axis isn't in the center, so when it is perpendicular to the vector of change (I hope you understand) ends of the rod touches 2 sides of the circle, but when it is parallel to the vector the distance between end 1 and end 2 is a diameter, what basically means the rod is too short. summarizing, springs were better
Just make sure that when you're making the plane it's built more like a glider, so it's easier for you to keep it in the air even when the air pressure drops
I love watching your iterative development process...mostly scientific but with just enough guessing (intuition) to make it fun. I have so many ideas from this. My only suggestion / concern is that 'hinge' on the teflon flaps. Surely that will fail at some point. I mean, nothing can bend like that forever. If it had an actual hinge, like a steel pin or something at that point, it could last much longer...maybe. Though that's another leak to account for. (*shrugs*) Oh, and I have mad respect for your use of math to solve the power equation needed to make the whole thing work. My hat is off to you. I wish I had studied more.
Grease will slow the whole movement. Low friction and light parts use very runny oils for lubrication. (if you drop a small screw into a blow of grease, it wont roll out of it anymore) The slower or heavier the movement, the thicker the lubrication gets. Using teflon as material eliminates the need of lubrication.
Grease (plumbers being one of hundreds of types and proporties) will act as a small liquid gasket sealing any tiny air gaps. Teflon may be friction free, but you still can't machine Teflon to run with no air gaps and expect it to be free moving. There are some greases that thin out when heat builds up, and although this air rotary design is only air, the compression then expansion of the air, through the motor, will generate a small amount of heat. Plumbers grease will thin out slightly with the heat yet still provide a reasonable seal. If not plumbers grease, there will be a grease that will be perfect, but it needs researching properly.
The blue liquid he pumped in showing the leaks is a good example. Imagine the liquid he pumped in smearing all around the front window of the motor. There's your liquid gasket. Or one huge liquid rubber washer so to speak.
You should check out the Di Pietro Rotary Air Engine. It operates on a principle similar to the pneumatic vane motor, with greater efficiency but can be harder to manufacture,
To improve: make side-flappies on the flappies and the rotor body to eliminate leakage against the flat surface of the housing body. Play around with angle and position of the entrance. I have a gut feeling that says you will get better yield at 5° further and slightly steeper stream angle (which now is perpendicular). And perhaps bring back the 3rd flap. Also, adding a second exhaust hole where the inlet no longer feeds the cavity, will reduce friction in the second half of the rotation...
Lets call them micro flaps (on the sides of the flaps). Why not have a slit for the exhaust (about 1/3 or 1/4 the width of the flap) extending around the back half of the motor for about 170 degrees (just under 1/2). No idea if these will help but they are ideas to try.
Ideas: 1.) Changing where the inlet is to try and use more mechanical advantage of the flaps 2.) Changing the length of the flaps or the ratio of diameters between wheel and chamber - the flaps fan up pretty wide in their most extended position currently which might cause some unnecessary drag on the sides. 3.) Try with more flaps again (should be easy to manufacture and test now) 4.) I am not sure you ever addressed the air leakage towards the front and back - yeah, you have leakage at the side of the chamber, but also towards the acrylic front and casing back from what it looked like
3D print a seal on the ball bearing, similar to a sealed bearing (or try a sealed bearing?). I suspect that reducing this source of air leakage will help. Also try adding oil into the chamber before you screw on the cover, instead of just pouring oil through the bearing. This oil may help take up some of the tolerances.
Armchair Design Ideas: 1. Increase the number of vanes to at least 3 to ensure at least one is always producing torque. 2. Progressively port the exhaust (teardrop shaped passage in the back housing) so excess backpressure can begin to vent as soon as that flap's specific trapped volume begins to decrease. 3. Buy a one-side sealed bearing so air can't leak through the ball race. 4. Clamp and glue the case instead of screwing to reduce mass (design in alignment tabs). 5. Build a small sliding-spool pressure regulator into the inlet because the one used for testing is entirely too heavy to fly. 6. Make the rotor wider (deeper?) and the vanes shorter so the conformal hinge doesn't have to flex as much, and your average moment arm will be longer. 7. And the crazy one: Commercial pneumatic vane motors sometimes use inlet air pressure to load the vanes against the walls instead of springs. The air is ported through the housing, into the rotor, and delivered into the rear of the vane cavity. Big advantage because the friction is directly related to supply pressure, meaning at light loads, you will have less parasitic loss. This might not work with flaps normally, but... since you have a resin printer, what if you modeled a Bourdon tube (like a pressure gauge or a party blower) into the vane to act as the spring?
I love the content, keep it up! An idea for some addition to the engine, add in exhaust recovery to recycle the air back into the bottles. This will obviously make your plane heavier but could potentially lead to longer use. Also as someone else pointed out the metal would add unnecessary weight so switching your bearing into a Teflon rod could possibly help.
The flaps could be made more robust as a pivoting hinge (it would probably introduce another leakage point, but might be worth a try). The hinge would just be a cylinder embedded in the circle. From the top, the hinge would look like a comma, with the circle part of the comma inserted into a corresponding round cavity in the rotating circle.
It would be so awesome to see a collab! First, one video that pits you both against each other facing an engineering problem, then another video in which, together, you both integrate the best of each design to produce the best possible solution! INNOVATION MUST COME NOT ONLY FROM COMPETITION, BUT ALSO FROM TEAMWORK!
Firstly Great video I loved watching every minute, you have some amazing skills and an engineers brain. I have a few questions and ideas. +FYI you're making a high bypass turbofan engine! Maybe you just don't see it yet but you will. 1) Why are you using a combustion style engine to generate power? Combustion engines are heavy and only work well when you have a big bang to harness all that immediate torque. What you are doing is basically trying to make a turbo! Have you tried or considered using a low pressure turbine engine? I would recommend looking at a high bypass turbofan engine as that is what you're essentially already making. They're lighter by design and you have your "rotary design" (Basically an inefficient turbine) in the centre already powering your bigger fan. Try replacing the rotary engine for a turbo, I could imagine you could make one with your 3D printer if its accurate enough. Just remember to balance it before use. 2) If you keep your rotary style engine maybe consider creating an exhaust where the low pressure gas can be reused into a turbo to harness any remaining energy? 3) If you don't plan to reuse the energy from the exhaust for it not containing enough pressure then why don't you create an exhaust that can point the escaping gas under the wing to help create more lift. 4) OIL? What oil are you using as lubrication? Also please note the correct oil can help increase pressure by stopping air from escaping once you have your tolerance in check. This is what car engine oil does but it needs to be hot for the viscosity to be right. In this case engine oil will be too think but an oil like WD-40 would be far too thin. I'd recommend AeroShell Fluid 41 as it has a lower viscosity at room temp or something similar. The hard part would be trying to keep it in the engine and recirculating, but if you can get this to work you'll have a better seal and less friction resulting in more power. 5) Propeller, maybe experiment with different designs for example low RPM designs, or a turbofan? Experiment with different pitch, size, blades and speed to see what works well with the with your engine efficiently.
16:43 adding a pressure regulator will make the engine run for longer but you are also adding more weight again. You're going to come to a point where you got your engine design perfect and then realize it still won't fly because it weighs too much
Hey there! I just watched your latest video on the compressed air engine, and I have a few thoughts and suggestions. First off, you removed one vane, leaving only two, and replaced them with those floppy things. Remember, as you mentioned before, more vanes generally mean higher RPM and power. So, have you considered adding more floppy things instead? Speaking of improvements, why not try lubricating the engine with graphite? It worked well for the rotary engine in your previous video, so it might be worth a shot here too. During the leakage test, I couldn't help but notice some noticeable leakage around the bearings. That might be something to look into. I'm a bit curious about your end goal here. If you're aiming for maximum flight time, the two-bar setup might be sufficient. However, if I were in your shoes, I'd consider increasing the pressure up to 2.5 bar for better power output. Lastly, when you eventually get this contraption airborne, I wonder if the pressure regulator might be too heavy for successful lift-off. Have you considered its weight impact? Keep up the fascinating work! I'm looking forward to seeing how this project develops.👍
Yeah I know, but I'm not English. I'm just shit at writing in English. It's also not necessary I mean no one will ever read this besides you. So yeah the translator does the thing for me.
Absolutely love watching you develop these! Couple thoughts I had: 1. Are you still using some lube with Teflon? Can't hurt right? 2. I think the compression/pressure goes down with travel. So, I think going back to more flaps would be better. Would love to know if this works! Tomatoes are disgusting!
oooo an engine that works via compliant mechanisms, that's fun! Biggest issue I see is that you probably have quite a bit of wear on this engine, even with such a low coefficient of friction, right? As long as it runs, it runs great, but eventually the pieces will wear down so much, you get too much leakage again, I think. With the flexure version you *could* try going for a three-finned variant again. Might be even better? Though two-finned seems to work rather well
To increase durability, you can make the flaps longer. Right now it looks like they are just about the ideal length for maximum leverage without leaks, but when they wear down it will very quickly start leaking since the flaps won't reach the edge anymore. So for a more long term engine, I would add maybe 2mm of length, slightly decreases efficiency but makes it much more reliable over time.
by making the flaps longer you gain a certain amount of built-in wear resistance the flaps may wear down, but they have to grind through the whole extra length of the flap....
@@Kram1032 as long as they aren't so long that the cross section of material touching the wall increases, it shouldn't be much more. however, if the flap is too long or thin then then it will overcome the strength of the teflon, sag and drag excessively along the wall
Add a casing around the motor and connect the intake to the space between the motor and the casing. This space will then be pressurized, preventing air from leaking out of the motor. It is particularly important to ensure that the shaft penetration is properly sealed.
interesting design! At my job, we have a hand-crank pump that we use to pump juice out of large drums. I have to disassemble the pump to clean it and it works basically the same way as your design. an inner housing holding spring-loaded fins sits off center to the outer pump housing and rotates when you turn the handle. the fins extend into the larger void at the bottom of the pump and retract as they go around. When its properly sealed up, it can create enough suction to rocket juice out at ungodly volumes!
If you notice, the two engine models are inversions of common compressor types. The first one resembles the piston-type compressor, and the current one is rotational. However, there is still another type to consider: the rotary screw compressor. Perhaps, by applying compressed air to a lightweight resin-printed, adjusted version of this type of compressor, rotational motion could be achieved more effectively, as the rotary screw design is the most efficient of the three. Only check the friction and leaks of air
Dude - you are very impressive - love your creativity and no limits thinking - your latest iteration is good - I would add small springs to the flaps to keep constant contact of flaps to edge - would even play around with using a light oil (inner engine SUBMERGED in light oil so that it could run indefinitely ) with flaps 'not' in oil, etc. - would take some iterations as you know. Best !
Get an exclusive 15% discount on Saily data plans! Use code Integza at checkout. Download Saily or go to saily.com/integza
Yes bro ❤❤
Thank you❤
PLEASE MAKE A ROCKET TURBOPUMP!!!!!!!!!!
PLEASE MAKE A ROCKET TURBOPUMP!!!!!!!!!!
PLEASE MAKE A ROCKET TURBOPUMP!!!!!!!!!!
Let me know when you get it flying 😉
Would love to see an in-person competition between you two ;)
He can't get it to fly
Do a competition for a video
He have all types of engine in the world but no practical use of it all he does is burn tomato atleast ur ones fly
i reckon get the 3d files , make the engine ,AND FLY
Issues to correct if you want to use this in a plane:
1. It weighs too much. Make it thinner, eliminate all of those bolts.
2. The shaft bearing is too large and bulky. Do you even need it? The rotor is made of Teflon which has low friction so maybe it can act directly as a bushing. Might help with sealing too.
3. Maybe go back to a 3 vane design now that you've changed the mechanism.
4. Experiment with different geometries for the exhaust port to exhaust faster and reduce back pressure. The vane is on an angle, so the exhaust port can match that angle across the whole vane length to the rotor along the swept area.
Bro, let us come with some genius solutions as well!😂
Somebody paid attention in their physics and engineering classes.
Check out the type of air seals used in jet engines. labyrinth seals. Also I forget what they are called. But there's little indented rings around mortar shells. Those help trap the gas without any friction with turbulence.
Of course both jets and mortars have a lot of gas so leaks are less of a worry than people think.
But there might be something worth stealing because they are both incredibly low friction.
He could also experiment with angling the vanes themselves, the same way the flaps were angled.
My first thought was to increase the number of flaps, but I see I'm way too late to post it.
Integza, about 23 years ago as my thesis project for Mechanical Engineering Technology, my friend and I designed a 4-bar mechanism that solved this problem.
We called it the QRP or Quick Return Piston, because it had a 270 degree downstroke and a 90 degree upstroke.
I still have the files and paper if you are interested.
Send it to Tom. Integza has his flappy engine now and can't go back.
Thats cheating. @MohamedTarikRochdi
Send it to both. Integza will make the engine
I probably don't have the technical expertise to produce anything from your thesis, but I'm very interested in reading it
Many ways to accomplish engines. I lean towards steam made by a rocket stove. Free fuel, simple parts.
I’m not an engineer or a designer of any sort, but I know how things work mechanically and build and repair things like this all the time. I just wanted to say that this was a great video. Humorous and engaging. I especially enjoyed how you displayed your errors along the way. From reading your comments and seeing how so much people seem to know more than you about something you clearly was experimenting with, I think you it’s safe to call any comment a win. You got all these know it alls to watch from beginning to end. Keep up the great work. Can’t wait for more! Aloha!
0:30 shots fired 😆
Nice
6:32 with the subsequent "I'm screwed"
Oooff 😂
lol, Hi project air love your channel
U gotta hop on to this challenge i want to see my maker youtubers compete
So here we go.
1. With only 2 vanes, the engine is pulsing. 3 or 4 would increase the surface area to catch the air.
2. The ball bearing is overkill, make the case tight around the shaft. Experiment with o rings or a ledge.
3. If you're regulating the pressure to 2 bar, then you can reduce the thickness and weight of the housing.
4. Instead of vanes, you could use disks. Alot like a tesla engine just small enough to save weight.
5. Rotating mass will be your friend for extended run times due to the light weight. Attaching the propeller with a larger single bolt will help the fluctuation in rotational speed.
6. Inceasing the size of the exhaust port would allow the air to easily escape, increasing the pressure difference on the inlet which would increasing torque.
All in all, a really interesting build and your build process is really relatable. Keep this series up until you battle Tom for air superiority!
The compressed air tools using this mechanism do usually have at least 6 vanes. More vanes will add friction but maybe still worth it?
If you add 4 flaps, you can also add 2 more inlets and exhausts (twice the power for twice the consumption)
More surface area more flaps makeit into a turbine
@@ns-li4pr Yeah, it's already half-way there with that tangential inlet port.
@@-danR The inlet Port should be putt more into an angel. Maybe 10° more degree towards the roation and three flaps. So the Air pressure is directed to the Flaps instead of "filling" the room.
You should consider increasing the number of flaps from 2 to 3, and either enlarge or add another exhaust port at a 120° angle to prevent compression. The operating cycle of your engine should follow these stages: inflation (at constant pressure), expansion (until atmospheric pressure is reached), and exhaust (again at constant pressure).
In your current design, the expansion stage is inadequate, followed by a compression phase. This increases the overall pressure and wastes a significant amount of energy. The exhaust pressure should be equal to atmospheric pressure, so it might be worth adjusting the intake pressure accordingly. Finally, it’s advisable to resize the model to match the required output power.
Perhaps I wasn't clear enough. In the 3-flap model, the first two cycles perfectly align at 120°, and in order for the third cycle to also match, the engine would need to allow for an exhaust phase during the entire 120°. This could be achieved with a large exhaust port throughout the entire stroke, or at least two ports-one at the beginning and another at the end of those 120°.
If necessary, an additional flap could be added, as more flaps increase the expansion ratio.
In the 2-flap model, air is injected for 180°, and expansion occurs only for 90°, resulting in a much lower expansion. For 2 bars of pressure, a 3-flap configuration is optimal
I was about to write the same, then realized you explained it perfectly! Congrats
You are absolutely right about the harmful compression. The exhaust should be at 180 + 180/flaps degrees from the input. However, it seems kind of wasteful to let that portion of the rotation do nothing.
I think if he has already abandoned the use of mechanical sealing and switched to flaps, he can make the chamber oval-shaped. This way, the expansion phase can be longer than the narrowing phase, with more degrees of expansion. Theoretically, it does not make any difference, but it feels like a more gradual expansion would be better.
This is what i was going to suggest, But i would go as far as going to 4, Since the area of efficient expansion will be partially overlapping the exhaust with 2 or 3.
@@Joy-R-Us The maximum expansion zone occurs with the flap set at 180° + (180°/number of flaps). As the number of flaps increases, the final expansion point shifts backward. Therefore, the exhaust port must be extended to that point to avoid compression, which also increases the expansion ratio. It is likely that 4 flaps are optimal for 2 bar pressure, but with improved efficiency, it may be possible to reduce the feed pressure and extend the flight time with 3 flaps.
First-time viewer and ME myself.
I have to give you props on showing how engineers make design ideas a reality and how we troubleshoot along the way. One tip would be to slow down the math calculation just enough (at least 2 secs) for people to pause the video and absorb the physics. Otherwise, you are killing it.
Stanton fans here
Stanton's pretty cool
so obscure!!
Don’t watch him that much but when I do he cookin
Could not believe he opened with Tom smack talk..
and D4A
I really like the flappy engine, because it was the 1st design that moved away from traditional pneumatic air motors used in air tools for the last century. Probably due to wear rates, but still, for the intended use it's a really well thought out work around towards efficiency, power and weight.
Also, introducing flexure to any mechanical design is the ultimate engineering flex - pun intended.
Hey, I came up with two ideas for this engine that might improve it (or make it worse):
-The first idea is to make the outer circle in the chamber into an ellipse and place the inner circle at the center (making the system symmetrical). Additionally, doubling the number of holes for air intake might help, but the intake holes would need to be made even smaller.
-The second idea (probably more interesting) is, rather than having holes that let air exit to the outside pressure, to connect them to a smaller bottle (or capsule) where the pressure is lower than the outside. This could create a situation where we control the airflow and generate additional force in the same direction.
I’m fully aware that this makes the system much more complicated and harder to run, but I think it could lead to even more interesting results.
By the way, I really like your videos!
13:29 "Teflon, which is the thing in your non-stick pan" Proceeds to show us a cast iron pan.
Hey, it's "non-stick" 😉
Isn't teflon getting banned or something?
@@GewelReal yeah, no one uses teflon on non-stick pans for decades now
@@aflac82you can still buy Teflon pans here in the uk pretty abundantly unless it’s a name gimmick, why would Teflon be banned is it harmful?
@@aflac82 Teflon is a brand name, it's actually just PTFE. A compound that was used in this material was carcinogenic and got banned. Your non-stick pan still has a 'teflon' coating.
Since the flappy engine has so much less friction, have you considered going back to a three vane or four vane, that way more of the pressure that’s coming in has a smaller expansion area before the next vane kicks in, I may not be explaining this correctly but a third or fourth vane should give it more torque and or speed, just note this is an idea before the end of the video, timestamp is 18:37…never mind I just realized the total length of the video😂
Also trash the bearings, instead make the rotor with the “shaft” built in and in the main block just have a blind hole and do the same on the front cap. That drops the leak area plus with it being made from PTFE, shouldn’t be much friction!!! {-o-} diagram for example!! Love your channel, and Tomatoes are totally gross!
@@studiowilds9879the mechanical strength and low friction in bearings is almost nessesary in this situation, any other mounting will be too much friction and too weak, but if he would add a simmering to make it airtight, it would probably work better, but more flaps could maybe be a trick as you explain above
He'll hit the sealing issues again probably
I should have read the comment’s 🤣 though I’m not sure how 4 flaps would work because 3 seems to be the magic number. It would be wild to see him try this….with and without lubrication. Either way, great minds think a like and I love your comment!
@studiowilds9879 bro….ceramic bearings….you are on to something. Are teflon bearing’s a thing?
make the engine housing from another material that is harder and lubricate it with graphite
powdery graphites are gonna stick in bearing lubricant and can slower them down
The advantage of oil is that it also works as a sealant.
@ojaswiagarwal-x1y 2rs bearings after time will not slower an engine
@@FedericoLucchi who said u cant have graphite and oil? i remember some old car oil had graphite in it
@dominikvarholik7519 zink.
THE TALE OF FRICTION VS LEAKAGE...
A way to eliminate some of the leakage as seen at 12:40 can be using sealed/shielded ball bearings or even better, fluid shield bearings! not only it'll eliminate the bearing leaks, it'll help the engine run smoother since the bearings are constantly lubricated.
I was thinking all the time the same!
The vanes (around 5:45) are being pressed back into the core of the rotor because there's a huge pressure differential between the outside of the rotor and the inside. It's air pressure that is forcing your vanes in. When the air pressure that leaks past the vane, into the center of the rotor, and out of the engine has dropped enough, centripetal force can overcome it and the vane closes again.
It would be interesting if there was a passage in the rotor where its entry went from the pressurized zone, through the rotor, and into the bottom of the vanes' "cylinders" so that the pressure is equalized.
Alternatively the centripetal force could still overpower the pressure differential if the diameter was made larger or the vanes heavier (v^2/r).
Mechanical engineer here. I'd be happy to provide sketches of either!
@@fernandosaenz4196 springs are always the answer to things like this
Use less diameter bearings to reduce the area of leakage in them. Also, it's better to have more volume of the engine cuz it improves the ratio volume/leakage.
Sealed bearings should also help
I believe if you have more volume in the engine the running time will lower because air in the bottle is still the same so % of air that is wasted is higher
Also smaller bearing makes it lighter. Higher chance that it flies.
Or 0 ball bearings, since it only runs for a couple minutes he could just use teflon sleeve bearings/bushings with some light oil or grease. Also if he was to change the drive shaft to steel he could use a much smaller diameter which would result in lower leakage around the output.
@@balrog240Sealed bearings would have much more resistance too
I've scrolled a lot of comments and haven't seen this one yet: The two-vane design might have more potential with a small spring in addition to the rod - because the shaft is off center in the chamber, when the rod is vertical the secant line is the full length of the diameter, but at any other angle it's shorter, so either the vanes are lifting off of the rod at the full diameter or you're experiencing leakage past the extended vane into the exhaust side.
Great video, it's fun to see the entire trial and error design process!
From what I'm seeing, you're putting more air through the stuff and never letting it out, that's why you get leaks.
There are 2 chambers separated by the vanes.
The first one gets the air intake and it's volume grows, that's fine.
The second one has a somewhat constant air quantity, but it's volume shrinks, it builds up pressure, resists the movement and ultimately generates the leaks. Add an outlet hole in this chamber.
If i'm right you might get a better seal, and less resistance from the outlet chamber.
At 10:33 you can see the hole in the model. I highly doubt Integza was unaware of this.
Nice use of a compliant mechanism,
It might be nice in a pump too
@@orestdubay6508 Yep my 50 year old marine engine used a vane cooling-water pump with "compliant" rubber impeller, It's a far older design than you think. Making it low friction is the challenge here though.
Given the friction, what about making the flaps replaceable tabs that lock in with a key fit, but doesn’t add extra leaks? After enough run time the flaps would wear down like apex seals do.
Several improvements are possible:
1. Drop huge 2 psi valve and resort to using a 3D printed reed valve integrated directly in the motor. Why? Weight. You need the lightest design to successfully fly for a long flight.
2. Drop the metal bearing and simply make a PTFE centre shaft as part of your motor redesign. Both weight and less friction will result plus less leakage.
3. Your use of PTFE is great to reduce friction and also deal with engine heat, but you still need some lubricant to deal with the micro leakage. I suggest providing a amount of light synthetic oil via the central shaft where you made the bearing replacement. The centripetal force will dispurse the drop sealing not only the central shaft and lubricating it but will fly to the outside of your leafs and then seal there to provide seal plus lubrication to the leafs. You thus solve both leakage issues.
On a final note, the Tesla Turbine concept which you do not mention (since it applies to fluids not gases) could draw inspiration by potentially using the exhaust gas the the outer edge to a perpendicular disc adjacent to the motor with the disc dimpled with half clam shaped dimples to catch the air but using a logarithmic sizing of reduced clam size as you work to the centre that would be exhaust port. Despite air not acting with the viscosity of liquid as Tesla design, the clam dimples could assist to additional acceleration of the central shaft of the motor. Of course such fabrication was impossible in Tesla days but with a 3D SLA printer it is. The only downside is additional weight to add this and also size since the larger diameter disc provides greater efficiency in the Tesla design. Since you wish to fly, just stick with the original 3 points. FYI - a recall around 2008 when a company out of India called Tata was proposing using air as the new fuel. They did make a prototype car but I think it only went 30km/h and so for small city driving. No clue on their engine design but I always liked the idea of air as the fuel with the exhaust as the air that went in! The question of how best to compress it likely created the additional complexity that we never saw it materialize.
gasses ARE FLUIDS!
I like how you post all of this yet don't even know the basics of gasses being fluids.
1: that pressure reduction value weights 10x more than the motor itself. A reed valve sets a minimum pressure not a max. How would that work? TATA discovered that the air in India was too dirty and clogged the compressed air engine. !!
@@stephencaparelli7733 I felt so smart when he said that! Maybe I can be an aeronautical engineer after all! But in actuality, I work at IKEA, and yeah, no.
The Tesla Valve might be an option
I have worked with fuel pumpsets that have air eliminators that work in a similar way,they remove air and prime the pump set. It has spring loaded graphite carbon fins that spin in a cylinder,the carbon also gets deposited to the cylinder wall which helps reduce friction and maintain a good seal. 👍🏻
The connected vains idea was a display of ingenuity.
wait for the flappy things
vanes
That confused me... I'm not understanding how they were both always in contact with the outer cylinder, when they were spinning in an offset radius; was there a spring in that shaft?
@@userzero9259 it doesn't matter that it was offset, all the matters was that they stay the same distance. if you're good at visualizing, imagine focusing on just the rod. it doesn't matter what else is rotating around it, it's just getting pushed back and forth from the pivot's POV
I LOVE the childlike naiveness of youtube comment section. It's not like pneumatic engines have been practically solved for years if not decades and literally anything seen in this video isn't new nor unkown to the content creator beforehand.
He's not even that good at pretending coming up with new solutions or being surprised at things like..... not using any lubricant, LMAO.
There is nothing sacred to him.... everything is a rocket for him
This is awesome. I love this little flappy engine; I think you have landed on what could be the new gold standard design.
Please check the sealing on the piston's axial direction. If you machine annular flap seals into both piston faces, remember that the propeller is pulling the piston towards the front, so the seals on the back face of the piston will have more clearance.
For even better sealing and less friction, you could make the entire expansion chamber PTFE, using the resin housing for structural support. Or just machine a grove in the housings for PTFE o-rings.
Finally, your bearing isn't the best one for an airplane. You need a thrust bearing in the front of the engine and a sealed bearing on the rear. The front bearing and engine housing is taking all the load of pulling the airplane forward.
Engineers are calling it the world's most stressed teflon strip
The pain of air engines...it's so addicting hah! Best way to reduce friction of the rotor further is to reduce contact area against the housing faces. So just have a small lip around the whole edge (plus the whole flap of course). Less area means less friction so you can have a tighter fit for less air loss and same friction. Or same air leakage with less friction. Really clever design, how long do those flaps last before fatigue failure?
They haven’t failed yet, Teflon is actually very resistant to fatigue stress
Contact area isnt really important for friction. You have to reduce the normal force and the coefficent of friction.
With the rotor fixed on the ball bearing and effectivly flying in the housing,giving the rotor - housing clearance a thight fit, you could increase the almost contact area there and smear it with thick grease to seal it.
Doesn't a smaller contact area mean there will be a greater chance of air leakage?
@@AA-rc6ob Should be less. Any point of contact is an opportunity for leakage. The force at any point of contact is directly proportional to the pressure - it doesn't matter how large of an area there is. However, the amount that manages to sneak through per area also depends on the pressure, so if there's more area, there's more total flow through that area. This is why his smaller nozzle provides longer runtime but less torque - it's the same force coming out per area of the nozzle but there's less area so less total flow.
Can u try to make a tesla turbine with this method?Nice video i love it!!!
I think the torque would be too low especially at the start. 😢
The whole point of a tesla turbine is to blow air directly on a set of discs, so unless you mean "scrap everything you were doing to make a Tesla Turbine instead", the mechanism he's using inside is taking up the exact spot he needs to make a turbine with.
esses motores funcionam melhor com fluídos que possuem viscosidade maior e é bom usa-los a uma pressão alta e constante
@User__Not__Found
Using this method, could you breed 2 giraffes?
Given the leakage occurs through the bearing, the bearing itself could be extracted from the main piece. It would be kept aligned to the rotation center axis, but only sustaining a center rod with minimal radius to be sealed against the pressure chamber.
You are correct, once he switched to teflon, bearing is just extra weight.
This video is amazing. I am in school for mechanical engineering and I want to go into the aerospace industry. This stuff inspires me so much! Thank you!
Man, this air rotary engine idea is crazy! Imagine using a nautilus spiral for the chambers resulting in smooth airflow, less turbulence, and max efficiency. Pair that with interlocking rotors, kinda like layers in a satellite design, and you’ve got continuous compression with almost no stress on individual parts. Oh, and dynamic balancing? Add some flywheels or counterweights to keep it running steady even at high RPMs. You could even go modular by stacking rotary layers like pancakes for more power and redundancy. And instead of just air, tweak the design for steam or gas mixtures too. Ducted pathways with adjustable vanes? Boom, variable compression ratios on the fly. Seal everything tight with optimized D:d ratios for minimal air leakage. This thing could integrate planetary gears straight to a generator or drivetrain, no problem. Test it out in CAD first to get those nautilus chambers airflow-optimized. Legit hybrid engine potential here!
Id love to test things like this myself… working towards that 3d printer lol
I think you should add a gear train to the engine. Also a teardrop exhaust port would probably help exhaust pressure to increase overall preference. You could use a seal or an o-ring around the shaft to prevent loss of air pressure.
Quick, simple, and requiring no major container changes: Increase the number of flaps. I KNOW you reduced the VANES to 2 to reduce leakage; however, flaps are different because the pressure increases the seal. Thus, more vanes means more torque AND without sacrificng sealing. NOTE: I am NOT suggesting going from 2 to 3; rather I AM suggesting seeking a sweet spot which might be 3,4,5, etc. to find the optimum between the net increase in friction with the net decrease in leakage. You MAY need to simultaneously seek a sweet spot with regard to pressure as well. Hope this helps. BTW, I love your presentation style.
i think it very much depends on how much friction each vane/flap causes, if there are two pressurised cavities (implying 3 vanes/flaps under some pressure) then the mid vane has pressure on both sides, albeit that the pressure in the cavity nearer the inlet ought to be greater than the cavity about to exhaust.
It's not that simple. If you have too many the airflow into the chamber gets cut off too soon. Most energy is probably extracted between 30 and 60 degrees after the inlet. With two flaps the movement after 60 is not helping much. With four or more you are not maintaining full supply pressure throughout the productive part of the cycle. It could be calculated more rigorously but my gut feeling is that 3 may be the optimum. You are right, his reason for moving to 2 has gone, he need more flaps.
@@nomdefamille4807 Thank you for your well considered response. In my mind I pictured sort of a water wheel -- but you may well be correct. I am not much of an engineer; I have always taken the million monkeys approach -- admittedly, more tortoise than hare; but it usually works in the end.😀
@@nomdefamille4807 Thank you for your insight. You are obviously a much better engineer than old kitchen chemist me. I had visions of a sort of water wheel efffect; but, that just might be the amateur in me. I still think something along those lines might be worth a shot. Who knows; even if it fails, it just might provide some iterative inspiration. 😀
@@tuberroot1112 FYI Commercial vane motors can have up to 10 vanes. It appears to be a judgement about lower friction vs lower internal leakage and RPM. As long as the vane still has space to expand outwards then the air can continue to expand. Given the inner rotor is offset from the outer, the rotor can rotate 180º and continue to expand.
I LOVE LOVE LOVE that you took on this challenge.
The pneumatic engine removes combustion dangers, allowing everyone to try new ideas on one of the most useful components of the modern world.
Converting stored energy into mechanical rotational energy.
Years could be spent tinkering with pneumatic engine designs. Its incredible the varied possibilities that exist, things that have never been thought up just waiting to be discovered.
My favorite video EVER that you've created.
Except needs more exploding "Tom"atoes.
Or you could just look at a Wankel
I must say I'm quite worried about you cutting through PTFE/Teflon, and even just using it.
Broken down PTFE is basically PFAS, aka. forever chemicals, where little amounts cause cancer eventually since they might never leave the body, and never leave the envrionment.
I'd just stay away from those, using PET, grease, parrafin-based wax, or other alternatives.
If you want to learn more, just search for PFAS, and/or watch the movie "Dark Waters".
Hello, in order to reduce leaks between the transparent plate and the rotor, you could install a series of 2 or 3 baffles, they are used in applications with very high rotation speed and high pressure. I remember this passage from my engineering classes. With the tolerances of your printer this might be possible. (sorry my english is bad it's not my native language)
Edit : There is no friction with this solution, because the two parts do not touch.
I was thinking some matched up oil grooves for the same leakage points. since it's a short duration doesn't matter much but needs sealed.
and a frigging o ring around the main body and clear plate. once the spinny bits are better sealed, that body is going to be the next spot.
I also thought he should try to stop that "3D" leakage. Perhaps the transparent plate (and rotor) shouldn't be flat.
No your english is not bad
@@Noksus thanks 😅
Like the set of grooves on a piston?
I just randomly happened to have this video pop up. I know nothing about air engines. But, this comment section, which I see as a super nerdathon...
Is probably one of the coolest things ever, seeing everyone providing so much help towards creating perfection.
I wish I could be like all of you.
As an engineer I've seen something similar in a marine application here's what I suggest. Use a 4° reverse vein use your pushrod design. Use graphite powder dry for a lubricant and gap filler. Your central peace should be two parts to clamshell against the veins and the pushrod unless you can get tight fitting as single piece. You may even be able to go to a three vein 2° reverse angle using a cam style to move the pins in a direction to keep the veins close to the outer shell. And you could then use a nitrite seal or similar automotive style seal on the output shafts of your rotary vein. That would minimize your parts your escape portions if you do the tight tolerance thing again with the seal it would keep everything much tighter with less friction minimizing your parts and less air gap
This guy is probably gonna win :/
The 2-part clamshell to get a tight fit around the sliding vanes is a good idea in theory. But that gap is already eliminated by being the solid attachment point of the flaps.
"veins?" ----> *vanes,* dude lol
NOBODY CARES!
I LOVE the video and your sense of humor. The single greatest problem with the flapper vanes is that fatigue will cause them to break very shortly. If you could design a type of hinge that would eliminate the flexing and then make that leak-proof, THAT would be pretty cool. As for Tomatoes; have you NEVER tasted a BLT or Bacon, Lettuce, Tomato Sandwich made with White or Sourdough bread and Hellman's mayonnaise? Obviously not. If you had, you would think of that as ambrosia; The Food of The gods.
THE LEGEND HAS UPLOADED ONCE AGAIN!
Yeah, I was starting to get worried about him.
Great work. I would love to see one of these as a range-extender.
3:50 your bearing don't rotate
Think the tiny balls are doing the work
👀
Doesn’t have to, the bearing isn’t connected to the outer wall
This video is INSANE. The amount of patient you have is outstanding. 😄... Now... where is the flying part? 😶
Ditch the bearing, use straight teflon on teflon. Machine the rear housing with the shaft your rotor sits on (rotor axle and rear housing is one piece) axial drill from the back into the shaft portion, not all the way through, and then drill a radial hole on the shaft. This will be your air inlet. Now on the rotor, machine it with the propeller shaft (as one piece) then drill 2 axial holes (on the rotor) to the center in a way that times the air inlet at the correct spot in the rotation of the rotor. (rotor shaft hole placement will be tougher to time) I would suggest a taper fitments at the base of the rotor shaft, and base of the propeller shaft, this will aide with thrust sealing caused by air pressure and the thrust created by the propeller. The blow by air (should be minimal) will help reduce friction and cool the teflon on teflon bearing. Obviously, you will need matching tapers on the rotor shaft to rotor and the rotor to outside cover. This design, in theory, will reduce friction and eliminate gaps (only 3 pieces now), reducing your escape losses. The hole on hole setup (when the air inlet hole on the rotors shaft lines up with the hole in the rotor) will act as the regulator, much like that checkball on the other guys motor.
Even just ditching the bearings and switching to a teflon bearing surface would be a big win
A Teflon bushing?
@DavidMulligan yes, but a bit more complicated. Using the air pressure to act as a cushion between the teflon pieces. Also lessens the amount of pieces, making less areas for loss.
Good point but probably you will need somewhat more pressure to make it kork properly, spetially having into acount the angular inertia of the blade
@@CrespoTorke8 That's why I mentioned tapers
More, longer, thinner flaps.
On the exhaust side, you need to make it easier for the air to escape.
Fill it with graphit powder as lubricant one time.
Yep, a dry lubricant would be beneficial, though I would go with molybdenum disulphide.
Yeah he went dual veins because of sealing and springs and kept it as he went to flaps but with the flap designs there is no reason to keep only two veins. Not sure if more veins will help getting better results but it should be tested for sure.
@@gg4760-k5n Three vanes will probably help, because as-is air inflow can leak over the back of the rotor to reach the exhaust and lose pressure. Three sections will allow a filling section, a power section, and an exhausting section.
would graphite powder help when he's made the entire rotating assembly in PTFE/teflon though?
I fully agree with the bigger exhaust though
more longer, thinner flaps makes for turbine, but that'd be heavier and brittle - engine that works till first touchdown? 2. Do we really need to sal friction of teflon against teflon? Doubt.
Simply fantastic work!
The pressure regulator acts like a restriction in the feeding line. The pressure drop is wasted energy (deltaP X Flow). You can compensate the pressure variation (and, thus, torque) changing the excentricity of the engine
Higher the excentricity, higher the torque for the same air pressure.
Note that, initially, when you have higher pressure,you will need a smaller excentricity to generate the needed torque. Lower excentricity leads to lower flow, thus reducing compressed air consumption.
When the air pressure is low, at the end, the excentricity is increased, sustaining the needed torque for longer.
This can be achieved with a movable engine housing, actuated by the inlet pressure
Look for "variable displacement vane pump"
Greetings from Brazil
I'm not convinced you're from Brazil, because you haven't invited him to come to your country yet, hahaha.
Yeah, I noticed the waste of energy in the pressure regulator as well. You reduce the pressure, but the amount of air molecules that are in the bottles and can go into the engine stays the same.
But wouldn't an engine with zero eccentricity waste air molecules instead? Yes, you get less force, but the air coming into the chamber is still 2 bars (or actually even more), and the "input cutoff size" of the chamber (the size at the point when the input port gets cut off) is basically identical to the "input cutoff size" at maximum eccentricity. And any time the chamber reaches the exit port, the pressure in it is still dumped from X bars above ambient to ambient pressure, even with zero eccentricity. I have a feeling that variable *eccentricity* only works for pumps.
For engines, you probably want to keep *maximum eccentricity at all times,* but "vary the position of the input port". With high pressure, you want to input port right next to the "apex" (where the rotor touches the housing), since the chamber is smallest there. But for lower pressures you'll want the input port moved to (or a secondary input port opened at) 90° from that position, where the volume change of the chamber is highest.
And obviously, varying the position of the input port with respect to the point where the rotor touches the housing can also be achieved by shifting the rotor axis, so that the point where it touches the housing moves with respect to the (fixed) input port.
Not sure about the energy loss. The number of molecules is the same but the volume of air will be larger. Energy loss would develop heat (the energy has to go somewhere) which doesn't happen in a pressure reducer.
That's awesome! Your engine works really well!
For me there were 3 separate moments that were like inspired:
Firstly the flappy engine is obviously great. When I saw the thumbnail I stopped scrolling just to look at it for a while, and once I figured out what it was doing I was like "oh shit! That's very cool and elegant!"
And then second was when you connected the vains together. That was brilliant! And so simple!
And finally when you made the parts fit exactly by using the grinding paste! That was really clever and I really liked it! And it was really cool how you said how you got the idea from learning how those ladies made those camera pieces fit together.
So yeah not that you should be taking cues from me on when to feel good about yourself, but I was really impressed by this video! And thank you because I enjoyed watching it.
The Flappy Engine has to be one of the most technical names ive ever heard.
Another name for it could be a Floppy Drive 😅
@@Simpayne68Wwell played 👏🏼
Most of them Carry the name of the inventor and or the first death cause by
6:40 Oh... it's the same problem that every real world wankel engine has: leak from the side of the rotor.
True, but this isn't a Wankel Rotor, it's a vane rotor.
3 design changes you might want to consider:
1. At 4:15 you throttled the engine via friction by reducing the nozzle size. Instead, consider adjusting the torque demand of your propeller (diameter, pitch) if you want to trade run time against power.
2. The rod idea at 11:23 is geometrically flawed: when it is aligned with both the centre of the rotor and the centre of the hub, it needs to be the diameter of the hub. However, at all other angles (especially perpendicular to this direction), it needs to be slightly shorter, as it no longer passes through the centre of the hub. Of course, this is no longer an issue with your flap design.
3. Perhaps you could add a flexible lip to the edges of your rotor that presses against the casing - through pretension and also through air pressure.
2. Doesn't make sense to me, the diameter of a circle is constant. Why should the rod change?
@@lih3391 but when the rod is in 0 deg (vertical) it goes via the center of the housing. When rod is in 90deg (horizontal) it goes through the center of the piston only which is offset - so shorter distance wall - center - wall.
@@karolstopinski8350ah ok, how did he get it to spin then? I dont see any weird mechanisms on it.
honestly a great design paradigm. There are not a lot of ways to improve it. Amazing work Integza!
Can't wait for Tom to make a new one, and this to turn into some mad competition
18:32 I would think that combining your flap design with your vane design would be best. Like a vane that has a flap sticking out of it, like a y ... you also might consider an o-ring seal around the core of the rotor, against the walls of the chamber. to prevent air from leaking that direction.
If you also put the flappy flap on the side the engine would have an even better seal.
Also, test again with 3 or more flapy's at a lower pressure. Maybe you can increase the runtime even longer.
Great video! I wanna see you build a rotary subwoofer, test its ability to move air, and create very low frequencies. I heard they can be pretty dangerous to use indoors because if you accidentally find resonance it can break walls, windows and stuff.
you should make the exhaust port bigger so the engine has less resistance while pushing the exhaust gasses out
As an engineering educator, this is shuch a great video: how to design in Engineering. Thanks.
Hi Integza, Phi here!
I have a bit of experience with vane motors and vacuums pumps. It looks to me like you can solve a bit of your tolerance problems by making your rotor larger, and the vanes shorter, in your flappy motor design. It will give them less opportunity to flex under the air pressure, and allow for you to run it faster or at least more efficiently. For the vane design on the other, narrower vanes are better, but the cavities should be sized such that there are extremely tight tolerances, and when the vane is fully extended there should be about 2/3 of the vane left in the gland, otherwise friction will try to drag it out of its space, causing more friction, and eventually self destruction.
Gaskets and rotary shaft seals are grand!!!
Three vanes are better than two in all regards.
Cheers!!!
★ use a roller wheeled tip on the end of the rod's tips, carve a matching groove around the ring, this will not only increase the life of the engine, but it will also reduce heat less drag and improves performance and its still air tight. it might even reduce noise 👌
Please make a version 2 of your turbo jet engine that will run for longer , it was one of ur best videos, I too felt the joy when it started working , plsss.
that was one hell of a thing
Yaa I felt the excitement too😉
UP
My favourite video of yours. It's just one good idea after the other.
Good luck kicking Tom Stanton's 🍅
Quickest/easiest fixes:
1. 3D-printed flap mechanism + teflon housing. CNC cutouts around flaps increase the volume of air wasted. Maximize pressure differential vs volume per compartment.
2. Print versions with different amounts of flaps. Finding the correct amount in theory will take forever. Just print versions with 2 up to 5(?) flaps and see what's most efficient. No math needed.
3. Use a liquid, plastic-compliant lubricant. It's basically a free sealing agent.
4. Ball bearing in the center really makes air leakage too easy. Teflon center shaft and a lubed bushing would have just as little friction and be much easier to seal.
5. The front and back wall need to keep the air in the flap compartments. Look up a "labyrinth seal". Perfect for rotating designs, easy to implement, basically zero friction. Add the lubricant, boom, got a great seal.
6. Where is your outlet? It wasn't entirely clear in the video. Just make sure the air escapes quickly after the halfway point, otherwise the engine is working against itself.
7. Housing with a nautilus shell shape, but with a very smooth transition, so it doesn't wreck the flaps or cause them to catch. Then you can use almost the full rotation for expansion. Adjust outlet position accordingly.
8. Make sure the back wall is stiff enough to make the deformation due to axial force from the prop negligible. Otherwise sealing the flaps will be even harder.
Those are all the easy ones I can think of.
Edit because I was being dumb.
My background is industrial maintenance. My recommendations are simple. 1: Enlarge the end of the housing to accommodate a lip seal on the shaft. 2: Put the on/off valve between the pressure regulator and the motor. Air flow does act funny sometimes. 3: Enlarge the housing to a pill shape and supply air to the second chamber. You may have to reduce the size of the restricted orifice going into the motor.
Just some ideas.
Oooh, so pressure regulator fills the reservoir, which feeds the engine
Yeah lip seal alone would give substantial gains
Your flappy engine is awesome! Great problem-solving there!
I know I'm too old for a Make-A-Wish, but I hope fate lets us hangout within the next 18-24 months.
Making a project with you is definitely on my bucket list. You seem like a genuine and funny person. Both of which I could really use right now.
4:30 your ball bearing is 100% not spinning.
That’s what I like the most 😂😂
To improve this wonderful tiny thing:
1. Center the air intake as much as possible for the airflow to hit the flaps (it's not about max torque, but about the air efficiently pushing them)
2. Make the flaps into a pelton turbine shape: if it's efficient for water, it's probably great for air too!
3. Get a bearing with a rubber side: a lot of pain was leaking through the bearing!
4. as @naasking was saying, experiment with 3-flap design and try to reduce back pressure
5. find the optimal width: with eiter software or a couple of prototypes, surely there is an optimal width that maximizes torque without killing rpm.
I hope this helps! Much love from Italy!
the traditional pelton wheel gets its advantage over the venerable water wheel by providing a course for the fluid to reverse direction in to an "unconfined space", so for that aspect the air needs to leak out. here i think he needs the torque of the "rotary piston". if he is currently running for 3 minutes against a need for 2 then he could open up the inlet nozzle slightly and increase the depth of the rotor/ motor. he really should try and dump the regulator, the assembly would better use the stored energy if it could withstand peak soda bottle pressure. and in terms of flight performance anything to reduce weight, as all others have pointed out.
@@nomdefamille4807 great point
The engine doesn't work because of airflow, it's the pressure differential of the air expanding inside the chamber that causes it to rotate.
@@NeilStansbury And what is an airflow/wind if not a pressure difference, you 'genius'?
@@dziubo1 I suggest you go and have a conversation with Mr Bernoulli and ask him to explain his gas principle to you, then you might be able to answer your own question.
You should now try 3 or 4 flaps now.
Bear in mind the Teflon fatigue and that it may not last too many open close movements. As well to ensure min air loss you may try some tiny soft springs, just to be sure they're always at max open. Optimize the engine before going smaller or changing the shaft..
Nice project!
Keep on doing what you're doing as is great!
add a ball valve before injection, reduce chamber size, make a spiral to open and close the ball valve only when you need it for the amount of air needed to achieve the rotation you need.
@integza 11:23 axis isn't in the center, so when it is perpendicular to the vector of change (I hope you understand) ends of the rod touches 2 sides of the circle, but when it is parallel to the vector the distance between end 1 and end 2 is a diameter, what basically means the rod is too short.
summarizing, springs were better
Yea that brought my attention too. It either make terrible friction or will be totally leaky.
Just make sure that when you're making the plane it's built more like a glider, so it's easier for you to keep it in the air even when the air pressure drops
I love watching your iterative development process...mostly scientific but with just enough guessing (intuition) to make it fun. I have so many ideas from this. My only suggestion / concern is that 'hinge' on the teflon flaps. Surely that will fail at some point. I mean, nothing can bend like that forever. If it had an actual hinge, like a steel pin or something at that point, it could last much longer...maybe. Though that's another leak to account for. (*shrugs*) Oh, and I have mad respect for your use of math to solve the power equation needed to make the whole thing work. My hat is off to you. I wish I had studied more.
Lubricate the whole inside with plumbers grease. It's thick so will help seal any tiny gaps but keep friction low. Worth a try.
Grease will slow the whole movement. Low friction and light parts use very runny oils for lubrication. (if you drop a small screw into a blow of grease, it wont roll out of it anymore)
The slower or heavier the movement, the thicker the lubrication gets.
Using teflon as material eliminates the need of lubrication.
Looking for this advice. A very thick oil can provide some sealing
@@juvenildr So does superglue. You still wouldn't use it on small moving parts ;)
Grease (plumbers being one of hundreds of types and proporties) will act as a small liquid gasket sealing any tiny air gaps. Teflon may be friction free, but you still can't machine Teflon to run with no air gaps and expect it to be free moving. There are some greases that thin out when heat builds up, and although this air rotary design is only air, the compression then expansion of the air, through the motor, will generate a small amount of heat. Plumbers grease will thin out slightly with the heat yet still provide a reasonable seal. If not plumbers grease, there will be a grease that will be perfect, but it needs researching properly.
The blue liquid he pumped in showing the leaks is a good example. Imagine the liquid he pumped in smearing all around the front window of the motor. There's your liquid gasket. Or one huge liquid rubber washer so to speak.
You should check out the Di Pietro Rotary Air Engine. It operates on a principle similar to the pneumatic vane motor, with greater efficiency but can be harder to manufacture,
It's an inverted vain engine like liquid piston design for Wankel, interesting
To improve: make side-flappies on the flappies and the rotor body to eliminate leakage against the flat surface of the housing body. Play around with angle and position of the entrance. I have a gut feeling that says you will get better yield at 5° further and slightly steeper stream angle (which now is perpendicular). And perhaps bring back the 3rd flap. Also, adding a second exhaust hole where the inlet no longer feeds the cavity, will reduce friction in the second half of the rotation...
Lets call them micro flaps (on the sides of the flaps). Why not have a slit for the exhaust (about 1/3 or 1/4 the width of the flap) extending around the back half of the motor for about 170 degrees (just under 1/2). No idea if these will help but they are ideas to try.
Ideas:
1.) Changing where the inlet is to try and use more mechanical advantage of the flaps
2.) Changing the length of the flaps or the ratio of diameters between wheel and chamber - the flaps fan up pretty wide in their most extended position currently which might cause some unnecessary drag on the sides.
3.) Try with more flaps again (should be easy to manufacture and test now)
4.) I am not sure you ever addressed the air leakage towards the front and back - yeah, you have leakage at the side of the chamber, but also towards the acrylic front and casing back from what it looked like
3D print a seal on the ball bearing, similar to a sealed bearing (or try a sealed bearing?). I suspect that reducing this source of air leakage will help. Also try adding oil into the chamber before you screw on the cover, instead of just pouring oil through the bearing. This oil may help take up some of the tolerances.
Apply 2bar pressure INTO the bearing, through the ball cage and chanel the air to chamber/s. Used air exhaust opposite side to atmosphere.
Armchair Design Ideas:
1. Increase the number of vanes to at least 3 to ensure at least one is always producing torque.
2. Progressively port the exhaust (teardrop shaped passage in the back housing) so excess backpressure can begin to vent as soon as that flap's specific trapped volume begins to decrease.
3. Buy a one-side sealed bearing so air can't leak through the ball race.
4. Clamp and glue the case instead of screwing to reduce mass (design in alignment tabs).
5. Build a small sliding-spool pressure regulator into the inlet because the one used for testing is entirely too heavy to fly.
6. Make the rotor wider (deeper?) and the vanes shorter so the conformal hinge doesn't have to flex as much, and your average moment arm will be longer.
7. And the crazy one: Commercial pneumatic vane motors sometimes use inlet air pressure to load the vanes against the walls instead of springs. The air is ported through the housing, into the rotor, and delivered into the rear of the vane cavity. Big advantage because the friction is directly related to supply pressure, meaning at light loads, you will have less parasitic loss. This might not work with flaps normally, but... since you have a resin printer, what if you modeled a Bourdon tube (like a pressure gauge or a party blower) into the vane to act as the spring?
The pressure on the tip of the vane is why it was popping inwards
Hey integza, try making a dyson-style fan only using ion thrust
I love the content, keep it up!
An idea for some addition to the engine, add in exhaust recovery to recycle the air back into the bottles. This will obviously make your plane heavier but could potentially lead to longer use. Also as someone else pointed out the metal would add unnecessary weight so switching your bearing into a Teflon rod could possibly help.
5:40 The resson is because the air inlet pushes them down when they shouldn't be
The flaps could be made more robust as a pivoting hinge (it would probably introduce another leakage point, but might be worth a try). The hinge would just be a cylinder embedded in the circle. From the top, the hinge would look like a comma, with the circle part of the comma inserted into a corresponding round cavity in the rotating circle.
It would be so awesome to see a collab!
First, one video that pits you both against each other facing an engineering problem,
then another video in which, together, you both integrate the best of each design to produce the best possible solution!
INNOVATION MUST COME NOT ONLY FROM COMPETITION, BUT ALSO FROM TEAMWORK!
Firstly Great video I loved watching every minute, you have some amazing skills and an engineers brain. I have a few questions and ideas. +FYI you're making a high bypass turbofan engine! Maybe you just don't see it yet but you will.
1) Why are you using a combustion style engine to generate power? Combustion engines are heavy and only work well when you have a big bang to harness all that immediate torque. What you are doing is basically trying to make a turbo! Have you tried or considered using a low pressure turbine engine? I would recommend looking at a high bypass turbofan engine as that is what you're essentially already making. They're lighter by design and you have your "rotary design" (Basically an inefficient turbine) in the centre already powering your bigger fan. Try replacing the rotary engine for a turbo, I could imagine you could make one with your 3D printer if its accurate enough. Just remember to balance it before use.
2) If you keep your rotary style engine maybe consider creating an exhaust where the low pressure gas can be reused into a turbo to harness any remaining energy?
3) If you don't plan to reuse the energy from the exhaust for it not containing enough pressure then why don't you create an exhaust that can point the escaping gas under the wing to help create more lift.
4) OIL? What oil are you using as lubrication? Also please note the correct oil can help increase pressure by stopping air from escaping once you have your tolerance in check. This is what car engine oil does but it needs to be hot for the viscosity to be right. In this case engine oil will be too think but an oil like WD-40 would be far too thin. I'd recommend AeroShell Fluid 41 as it has a lower viscosity at room temp or something similar. The hard part would be trying to keep it in the engine and recirculating, but if you can get this to work you'll have a better seal and less friction resulting in more power.
5) Propeller, maybe experiment with different designs for example low RPM designs, or a turbofan? Experiment with different pitch, size, blades and speed to see what works well with the with your engine efficiently.
1:23 fricking finally
3:20 that poor bearing not even able to do it's job.
Maybe you could try graphite powder to coat the internals, which would also reduce the friction, It would be like having oil but completely dry.
I thought graphite was slightly abrasive?
please PLEASE work on this more. I'm in love with this weird engine! I'm also doubly invested because I loved Tom's video!
16:43 adding a pressure regulator will make the engine run for longer but you are also adding more weight again. You're going to come to a point where you got your engine design perfect and then realize it still won't fly because it weighs too much
He could probably just make like a 3D plastic printed nozzle valve system that would cut the weight
Hey there! I just watched your latest video on the compressed air engine, and I have a few thoughts and suggestions. First off, you removed one vane, leaving only two, and replaced them with those floppy things. Remember, as you mentioned before, more vanes generally mean higher RPM and power. So, have you considered adding more floppy things instead? Speaking of improvements, why not try lubricating the engine with graphite? It worked well for the rotary engine in your previous video, so it might be worth a shot here too. During the leakage test, I couldn't help but notice some noticeable leakage around the bearings. That might be something to look into. I'm a bit curious about your end goal here. If you're aiming for maximum flight time, the two-bar setup might be sufficient. However, if I were in your shoes, I'd consider increasing the pressure up to 2.5 bar for better power output. Lastly, when you eventually get this contraption airborne, I wonder if the pressure regulator might be too heavy for successful lift-off. Have you considered its weight impact?
Keep up the fascinating work! I'm looking forward to seeing how this project develops.👍
I totally agree 👍
At least rewrite in your own words what the AI outputs my man
Yeah I know, but I'm not English. I'm just shit at writing in English. It's also not necessary I mean no one will ever read this besides you. So yeah the translator does the thing for me.
Springs? Why not magnets??? 6:00
Because springs are better
Lighter and provide more force
Why not air pressure?
@@jmsterdam wasting air
Won't worry at that speed
There are ball bearings so that doesn’t work
Absolutely love watching you develop these! Couple thoughts I had:
1. Are you still using some lube with Teflon? Can't hurt right?
2. I think the compression/pressure goes down with travel. So, I think going back to more flaps would be better. Would love to know if this works!
Tomatoes are disgusting!
oooo an engine that works via compliant mechanisms, that's fun!
Biggest issue I see is that you probably have quite a bit of wear on this engine, even with such a low coefficient of friction, right? As long as it runs, it runs great, but eventually the pieces will wear down so much, you get too much leakage again, I think.
With the flexure version you *could* try going for a three-finned variant again. Might be even better? Though two-finned seems to work rather well
To increase durability, you can make the flaps longer.
Right now it looks like they are just about the ideal length for maximum leverage without leaks, but when they wear down it will very quickly start leaking since the flaps won't reach the edge anymore.
So for a more long term engine, I would add maybe 2mm of length, slightly decreases efficiency but makes it much more reliable over time.
i mean, why stop at three finns? as i understood it, the more the better
by making the flaps longer you gain a certain amount of built-in wear resistance
the flaps may wear down, but they have to grind through the whole extra length of the flap....
longer flaps means mroe durability, but also more friction, right?
@@Kram1032 as long as they aren't so long that the cross section of material touching the wall increases, it shouldn't be much more.
however, if the flap is too long or thin then then it will overcome the strength of the teflon, sag and drag excessively along the wall
Finally, another upload from you!
Add a casing around the motor and connect the intake to the space between the motor and the casing. This space will then be pressurized, preventing air from leaking out of the motor. It is particularly important to ensure that the shaft penetration is properly sealed.
You'd still have to seal around the bearing and the rotor so the intake chamber doesn't leak into the exhausting chamber.
HEAVY!!!
interesting design!
At my job, we have a hand-crank pump that we use to pump juice out of large drums. I have to disassemble the pump to clean it and it works basically the same way as your design. an inner housing holding spring-loaded fins sits off center to the outer pump housing and rotates when you turn the handle. the fins extend into the larger void at the bottom of the pump and retract as they go around. When its properly sealed up, it can create enough suction to rocket juice out at ungodly volumes!
4:39 spun is correct 😊
If you notice, the two engine models are inversions of common compressor types. The first one resembles the piston-type compressor, and the current one is rotational. However, there is still another type to consider: the rotary screw compressor. Perhaps, by applying compressed air to a lightweight resin-printed, adjusted version of this type of compressor, rotational motion could be achieved more effectively, as the rotary screw design is the most efficient of the three. Only check the friction and leaks of air
18:45 Hero's engine is truly awesome, so is yours!
Dude - you are very impressive - love your creativity and no limits thinking - your latest iteration is good - I would add small springs to the flaps to keep constant contact of flaps to edge - would even play around with using a light oil (inner engine SUBMERGED in light oil so that it could run indefinitely ) with flaps 'not' in oil, etc. - would take some iterations as you know. Best !