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.
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.
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.
Awesome project, and trying out so many materials is really impressive! But like you said, sealing these kinds of motors is really tricky. You know, I worked on something similar too. By the way, I was thinking, it might’ve been better if you moved the bearing near the transparent cover to the outside of the cover. That way, you could’ve added a small O-ring to the cover and probably stopped the leakage there. Great video as always!
Nice idea! Have a back half and a front half. Front half would just be a front bearing and crankshaft to the propeller. Connect the two rotating parts via magnets. The issue would be you'ld want strong enough magnets to keep the parts connected but not so strong they tried to clamp together causing friction.
I want to say no, that won't work but I can't think of any reason it wouldn't that couldn't be overcome with some clever design. At least for very low power applications like this. Yeah, I can think of several things that would prevent the motor working but they are all things that could be solved easily. Nice idea.
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.
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.
If you keep if named flappy valve it should probably resemble flappy bird! Could you replace the vane system with a compliant mechanism? For optimization: I think you can change the expansion chamber to be more round and have a better flow profile. Second, you could adjust the volume of the expansion chamber. Third, adjust the amount of flaps. Optimizing these could produce a higher rpm and longer run time.
@@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.
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.
Hmmm, what about swapping the ball bearings for a Teflon plain bearing to reduce leaks? Reducing the rotors diameter and making the flaps longer (F=P*A) could make it run at lower pressures while maintaining the rpm, also if you make the exterior out of Teflon maybe the rotor flaps can be made of some flexible material that seals better and using some graphite powder you could reduce friction even more. You could also try playing with the inlet and outlet diameters to squeeze the engine for performance
Remember that back pressure is important to the performance of the engine. I mean exhaust my boy. Play with different size exhaust and see the performance. Good luck and excellent videos.
I think in this case you want it to escape as fast as possible to reduce the engine working to compress it through the exit. So as big as possible at the correct timing where the air isn't providing work anymore
Back pressure in the exhaust is bad for these things. It would run even better if you could draw a vacuum on the exhaust. In fact, you wouldn't need any positive pressure on the intake if you could draw a vacuum on the exhaust, it would run.
If you were looking to make this engine fly, you ideally want to have an aft feed into the chamber with an aft exhaust as well (small amount of air going backwards will give a small amount of fwd thrust). Making the body longer, with a longer chamber will also help with the weight and balance, and should improve the efficiency of the engine due to longer vanes able to utilise more of the available pressure
1. Use graphite with the tight fitting 2. Make the exhaust hole bigger 3.the pressure is being given all the time, in Any way you could let the the presure being given to some distance and stop it after reaching some distance and let the cycle (like the piston engine the presure is given for some distance and it's stopped in piston engine and let air expand) repeat it will last longer than 3:22 4. Add an exhaust to the point wre the 2 flap is getting closed (time 15:59)
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.
Very interesting. I wonder... ...if the plastic hinges in the flaps might prove to be a weak spot, fatigue. If so you could get similar but more long-lasting performance by separating the flaps from the rotor but having one socketed in to the other - a 2D projection of a ball and socket joint. Next: It might be useful to have the flaps wider where they meet the housing - a combination of 'bucket shape' and extra material at the seals may help efficiency and leaks. Next: If the rotor and flaps had thin channels cut in their front and rear housing surfaces you may be able to use a combination of centripetal force and raised air pressure in those channels to act like piston rings. Next: Within reason (overall efficiency) a motor with a larger volume will have relatively smaller surfaces from which to leak. Next: Sealed bearings might reduce leaks.
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.👍
Note: this is purely constructive feedback on the engine (and normal criticism on tomatoes) 1. Making the compliant-mechanism flaps looser(thinner) will allow centrifugal force to seal it even better, white allowing the teflon to sort of jump over any bumps in production 2. You could put the inlet at an angle to decrease turbulance in the engine 3. This may be cheating a bit but you could use the output as propulsion (like a rocket!) 4. Sand the outer part with fine sandpaper to decrease cnc inperfections. 5. CNC the back part into the outer shell to decrease air leakage 6. Adding on to (3): use de Laval nozzle 7. FLYWHEEL 8. Silicone sealant to stop leakage TOMATO CRITICISM: squishy, slimy, fruit-vegetable crossbred that cannot decide between sweet and sour, only remotely useful for lubrication... sike! their chunky flesh makes even that a horrible use! plasticky skin, with liquid interior make them a nightmare to cut and use, with skin sticking to the top of your mouth!!! Add more criticism in comments
Dude this is amazing problem solving and creative thinking! ** Suggestions** - Design a little longer contact patch with enough for polishing to seal - Go to 4 flaps - increase motor size by 3% & and adjust flow rate accordingly 😀
You should make an radial lip seal that closes in the axial direction towards the bearing as part of the front of the transparent housing behind the bearing. Or an axial shaft seal. .
I can think of 2 things to improve the design. 1. I think redesigning the flap and pocket that it sits in could help with torque. The air is "pushing" on the flap like a lever, but if the flap is not strurdy, then it could be like trying to push something with wet speghetti. You could design it so that the pocket the flap sits in is where the mechanical leverage is applied, and the flap acts more like a valve than the crank for the air to push on. 2. You can try to make the housing one solid print that you do not assemble. So you would print half of the housing and then pause, insert the crank wheel, and then continue the print. So, when it's finished, the housing is one solid piece that you don't have to seal up. Try to take advantage of the flexibility of 3D printing more.
Using a sealed bearing may help. Also going back to the 3 vanes (now flaps) would also help, as you explained earlier in the video, you are loosing speed by increasing the chamber size, so more flaps would give you more torque. If you can’t get sealed bearing, you may use a lip seal outside of the bearing. These vane motors normally have aluminium cases and graphite vanes. The vanes seal by air pressure that builds up behind them, but I have also came across a 4 and a 8 vane design with the rod solution. I think you have done a great job on this motor and the main changes I would try would be these, more flaps and a seal on the bearing.
Yes finally, i love printable vane engines! I think maybe you could improve it by A) reducing the space between the rotor and the wall, this reduces the air needed and may affect torque, but there is less area to seal, and B) doing so may allow using a small strip of flexible material like TPU to be inserted in a solid rotor, or making smaller compliant flaps like the last design. I think reducing the amount of movement can allow them to seal better (at 17:50 you can see the flap detached from the wall when the pressure went too low to push it against the wall) and C) maybe using a thicker grease to lubricate the engine will provide more sealing, just like engine oil does. Also it may be fun to experiment with the number of flaps. I've always wanted to try printing one of these, thanks for sharing this Joel! I'm only slightly disappointed you didn't smash a tomato with it. Tomatoes are disgusting. :D
Also, if you want to maximize performance, try different propellers. rctestflight's boat propeller contest really showed how important it is to match the propeller to the torque/RPM curves of the motor/engine. Reducing the space between the vanes and rotor will decrease torque but increase RPM, so you can compensate for that using a different propeller.
Maybe make a cylindrical cutout in the cover where the rotating part of the engine slots in, then you could make a flappy seal inside the cutout so the engine doesn't leak as much air. also you could try graphite powder for lubrication! In my mind a powder also reduces leakage because the particles block some of the air?
optimization: 1:a 2 stroke expansion exhaust would be perfect as you are running within a small rpm bandwith. additionaly positioning of the exhaust is key. 2: take advantage of the centrifugal forces on the ''flappy'' valves. Give them more weight to allow for better sealing 3:silicone the living *tomato* out of every gap (at least on the outside/housing)
Hey There!! Instead of using flaps that bend and break, consider incorporating cavities in the central bearing that align precisely with the pressurized hole during rotation. This approach allows the rotor to be centered to the outer bearing, ensuring a better seal. It also enables you to optimize the volume to the intended pressure that maximize efficiency and duration of flight.
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....
I would love to see an engine with multiple staged chambers, like some water pumps. The waste air could be used back and sent to the second or third chamber.
It might be an insignificant detail but the actual anagram of ''Tom Stanton'' is Tomato's TNN.Anyway to add to the topic of the video the leakage can be mitigated(even possibly eliminated?) by altering the design to add side and apex seals like these on the Wankel rotary engine on every point of contact between the rotor assembly and the housing but this would add complexity and manufacturing properly toleranced mechanical elements of this size is itself alone an engineering endeavor.
I love how you realize that Tom Stanton actually decided to go for the most efficient engine he could make at that time. I hope he takes your flappy engine and continues making the airplane once he settles on how to regulated the pressure (because the piston engine basically limited the air use).
very interesting design, i might recommend that you add a circular flap/seal, angled slightly outwards, so that the engine would seal from the shaft and automatically adjust the tension by air pressure. very cool concept and i hope you get it optimized.
Use babbits or graphite as the housing material to reduce friction. Also try recessed reliefs on the flat side to reduce leakage. Kinda looking like a dove tail type joint.
That flappy design is pretty cool. I was annoyed at first because I don't really like vein engines and all their potential problems, but you solved a lot of them by keeping it one piece.
If you were to print the flaps in the extended position, then you wouldn't need to rely on centrifugal force and the pressure to extend them to the crank case. This probably would increase low rpm and low pressure performance I assume.
Suggestions 1. Making the ends of the flaps thicker so that they don't get worn out 2. Making this flap sticker will increase the centrifugal force thus the flaps will get closed faster and there will be more pressure difference between the both chambers 3. And although you may also decrease if possible the radius of the of the rotor so that its moment of inertia decrease also you get more area upon the flaps show more force Also making an engine out of ice can workout in liquid nitrogen if possible then or else in case you can use nitrogen or liquid nitrogen as the compressed gas 😂😂😂😂
Make the engine using carbon fiber or metal 3d printing(much harder) or just ceramic as u did in the Aerospike rocket engine video it will be much more durable and don't forget to lubricate the engine with graphite(pls like I really need a 3d printer the one at my school sucks it takes 2 days just to print something small and services are super expensive)
For longevity, there are similar things to that "flap" built into the back hubs of bicycles. Meant to only apply torqe in one direction so your pedals won't go around all the time. There are things you can borrow from such designs, such as small springs instead of that plastic that must wear out to metal parts with low friction oils.
I don't know if you wanna invest more time in this project, but i do think that a harmonic transmission should help a lot. If you take time to 3d print one so it has less weight than a metal one for the plane and then put more flaps in the vane engine which will create more torque so the transmission converts it to more speed and then manage to regulate the pressure it should greatly increase the succes of this project. I really hope you try this!
For the side issue to the bearings, the Labyrinth seal is your choice to go the hing design is a bit to flimsy for longer runs like an hour or more but if you aim still for a few minutes thats fine. Your enclosure also would be good to be done from teflon, because teflon on teflon reduces friction even more. And to increase the torque it would be good to increase the diameter of the rotor as this is the lever in the equation. Next in row would be the surface of the flaps. Best regards Michael
Tom Stanton is actually short for Tomato Stanton so good catch there! Also I recently saw someone build something similar but they machined in these 'cooling vents' throughout the casing with the purpose of redirecting escaped gasses back into the chamber!
Some ideas on trying to make it better... The leakage out of the front plate. The only way to do that I think would be an oring. But an idea would be instead of a traditional rubber oring. which would need a little oil to reduce the friction, maybe try one out of ptfe. or essentially machine it into the design. Like instead of having a flat boss have a ring of ridges that are high enough that can be compressed slightly then using the lapping compound will help in making it a tighter fit. It needs to be a circle so it follows the same grooves. If you want it to be a wear item just machine the groove into the face and either make or buy flat ptfe orings. Also now since you have removed the need of using vanes and instead using flappers. Maybe try multiple flappers? With planes they need to be light, so if you want to use it for an airplane you will need a very light pressure regulator.
My suggestion is, move the seal. You need to seal around the bearing. To reduce the friction force, you want the seal as close to the center of rotation as possible. So move the side seal (which is currently located around the perimeter of the rotor) inward to a ring with a diameter just larger than the bearing. But, you will need to connect this inner ring seal to the flap, which you can do with a thin extension from the ring to the flap... like your apex valve, but on the sides of the rotor. Do leave all of the material of the rotor (except for the seal) in place to take up volume. The less volume your expansion chamber has, the less air is required to raise the pressure.
graphite powder to lower friction and fill gaps, o rings on parts that arnt moving, frount pannle with o ring to tryt and close off the bairings, you can use lose oings on the flap parts as the air presser can over come the small bit of frishion, a shaped nozzle
Hi Integza! Love your videos. My thoughts go directly to planing the surfaces between the casing compartment of the impeller and the transparent plastic covering, maybe with the impeller assembled during the process to ensure the tighest fit without friction. And perhaps use a teflon lining inside the casing.
The usage of teflon is so cool. I think the obvious next step is the airplane. Some kind of your own 3d printed presurre valve for staying light weight could be interesting.
Make a gasket, the diameter of the housing, and spray with silicon. Seat the gasket beneath the outer wall of the motor. You lose your visibility, but seal the unit.
The improvement I would suggest is to replace the current bearing with a sealed one. That way you stop the air from escaping to the outside and hopefully this will "plug up" all the other leaks aswell.
I thoroughly enjoy both this channel and Tom's - send the engine to HIM. He's got plenty of experience making ultralight models that fly on modest power. Tomatos are excellent. You just haven't had the right one yet.
Vent the exhaust into a second (smaller) motor of the same type to more efficiently use all of the air pressure. To make a better seal against the top and bottom of the motor, use a rounded surface on the top and bottom of the main rotor and sand a concave divot using the the rotor in the same way you explained in the video and use bearings that have ceramic or gem balls along with a seal over the race.
Adding more flaps would be good since you don't have to worry as much about the sealing. Maybe it would be cool to compare the engines with the different numbers of flaps too. Also seemed like at slower speeds the flaps don't press against the walls very well. Maybe you could print them in a more extended position so they press against it more? Might be another compromise with friction though, but could mess with and find some best angle.
maybe some high tension elastic bands around the bottles that will squeeze them as they lose air to help maintain a constant pressure to smoothen out the blade speeds.
Once you moved from vanes to flaps, I had two thoughts 1: wouldn't more flaps add more power output? Try six flaps. And that should also limit the wear and tear on each individual flap. 2: I remember reading way back in the day that hot-rodders (not sure that translates across languages and times, but people who built or modified cars to make them go faster beyond legal limits) discovered they'd get more power out of a car's engines if they modified the piston heads to be cupped instead of flat. Maybe put divots in each flap to catch more air?
Really interesting progress on how engeneer résolve problem. My think is to create a rotary chamber with vein to limit leaks. Like the support for 3D printer filaments.
The concern I see with the flappy design is the very thin section of material doing most of the flexing. For longevity I would make that thicker and put the base of the flap deeper into the body of the rotor. On the subject of sealing, a couple of thin O rings on the bearings would probably prevent leaking through that vector. I would also look into how much the flat front and back plates are flexing under pressure because even with the O ring, if those are deforming you're going to lose air that way.
@Integza Loving this style of video!! Maybe add a small pulse jet engine on the rear when you eventually get it up in the air. If you have a controller you could always start the engine up mid flight for a boost and sound amazing.
Great work! Multiple stages would increase the amount of energy you can extract from the air, and leakage between stages is an insignificant problem compared to direct leakage without any work done. Measuring the exhaust temperature should give a good indication of relative efficiency, as pure adiabatic expansion even from just 2 barg to atmospheric makes air really cold. But, it would be a rough relative measurement for such short runs, as the air heats up from heat in the engine. But it could be useful to evaluate change in efficiency from minor changes, as long as the initial temperature of the system and other factors are about the same in each test.
i think you should consider the expansion ratio of the gas in the chamber and see how much it expands and what the pressure is when it's expelled. if it's not the same as the atmosphere, you're wasting efficiency. the seal between the inner cylinder and the outer cylinder is good for the flapy engine but it sounds like there are still leaks between the front and back face and the spinning cylinder. you can try incorporating a mechanical seal mechanism to try to alleviate this but i'm not sure how it'd work. another idea i had is to make everything out of a very hydrophilic and low friction material and have some amount of water in the compressed air bottles so when the air gets injected, it carries its own lubricant as well as providing a potential seal with water. not sure if this'll work at all.
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
0:30 shots fired 😆
Nice
6:32 with the subsequent "I'm screwed"
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.
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.
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
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
There is nothing sacred to him.... everything is a rocket for him
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.
Awesome project, and trying out so many materials is really impressive! But like you said, sealing these kinds of motors is really tricky. You know, I worked on something similar too. By the way, I was thinking, it might’ve been better if you moved the bearing near the transparent cover to the outside of the cover. That way, you could’ve added a small O-ring to the cover and probably stopped the leakage there. Great video as always!
Could you use magnets to connect the rotor and propeller? You'd eliminate the bearing leaks, and the additional weight may act as a flywheel
Nice idea! Have a back half and a front half. Front half would just be a front bearing and crankshaft to the propeller. Connect the two rotating parts via magnets. The issue would be you'ld want strong enough magnets to keep the parts connected but not so strong they tried to clamp together causing friction.
I want to say no, that won't work but I can't think of any reason it wouldn't that couldn't be overcome with some clever design. At least for very low power applications like this. Yeah, I can think of several things that would prevent the motor working but they are all things that could be solved easily. Nice idea.
THE LEGEND HAS UPLOADED ONCE AGAIN!
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
Great video! I would try using oil in the engine as a sealant though. like how cars use oil as a sort of a gasket in the pistons
As an engineering educator, this is shuch a great video: how to design in Engineering. Thanks.
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.
If you keep if named flappy valve it should probably resemble flappy bird!
Could you replace the vane system with a compliant mechanism?
For optimization:
I think you can change the expansion chamber to be more round and have a better flow profile. Second, you could adjust the volume of the expansion chamber. Third, adjust the amount of flaps. Optimizing these could produce a higher rpm and longer run time.
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.
Cool!. Congrats!
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
Can't wait for Tom to make a new one, and this to turn into some mad competition
Hmmm, what about swapping the ball bearings for a Teflon plain bearing to reduce leaks? Reducing the rotors diameter and making the flaps longer (F=P*A) could make it run at lower pressures while maintaining the rpm, also if you make the exterior out of Teflon maybe the rotor flaps can be made of some flexible material that seals better and using some graphite powder you could reduce friction even more. You could also try playing with the inlet and outlet diameters to squeeze the engine for performance
Try using a sealed bearing or bushings with seals and machine the outer case out of a graphite block.
Remember that back pressure is important to the performance of the engine. I mean exhaust my boy. Play with different size exhaust and see the performance. Good luck and excellent videos.
I think in this case you want it to escape as fast as possible to reduce the engine working to compress it through the exit. So as big as possible at the correct timing where the air isn't providing work anymore
Back pressure in the exhaust is bad for these things. It would run even better if you could draw a vacuum on the exhaust. In fact, you wouldn't need any positive pressure on the intake if you could draw a vacuum on the exhaust, it would run.
If you were looking to make this engine fly, you ideally want to have an aft feed into the chamber with an aft exhaust as well (small amount of air going backwards will give a small amount of fwd thrust).
Making the body longer, with a longer chamber will also help with the weight and balance, and should improve the efficiency of the engine due to longer vanes able to utilise more of the available pressure
The connected vains idea was a display of ingenuity.
1. Use graphite with the tight fitting
2. Make the exhaust hole bigger
3.the pressure is being given all the time, in Any way you could let the the presure being given to some distance and stop it after reaching some distance and let the cycle (like the piston engine the presure is given for some distance and it's stopped in piston engine and let air expand) repeat it will last longer than 3:22
4. Add an exhaust to the point wre the 2 flap is getting closed (time 15:59)
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.
The Flappy Engine has to be one of the most technical names ive ever heard.
Use magnetic coupling to eliminate leaks altogether
Very interesting. I wonder...
...if the plastic hinges in the flaps might prove to be a weak spot, fatigue. If so you could get similar but more long-lasting performance by separating the flaps from the rotor but having one socketed in to the other - a 2D projection of a ball and socket joint.
Next: It might be useful to have the flaps wider where they meet the housing - a combination of 'bucket shape' and extra material at the seals may help efficiency and leaks.
Next: If the rotor and flaps had thin channels cut in their front and rear housing surfaces you may be able to use a combination of centripetal force and raised air pressure in those channels to act like piston rings.
Next: Within reason (overall efficiency) a motor with a larger volume will have relatively smaller surfaces from which to leak.
Next: Sealed bearings might reduce leaks.
you should make the exhaust port bigger so the engine has less resistance while pushing the exhaust gasses out
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 👍
Note: this is purely constructive feedback on the engine (and normal criticism on tomatoes)
1. Making the compliant-mechanism flaps looser(thinner) will allow centrifugal force to seal it even better, white allowing the teflon to sort of jump over any bumps in production
2. You could put the inlet at an angle to decrease turbulance in the engine
3. This may be cheating a bit but you could use the output as propulsion (like a rocket!)
4. Sand the outer part with fine sandpaper to decrease cnc inperfections.
5. CNC the back part into the outer shell to decrease air leakage
6. Adding on to (3): use de Laval nozzle
7. FLYWHEEL
8. Silicone sealant to stop leakage
TOMATO CRITICISM:
squishy, slimy, fruit-vegetable crossbred that cannot decide between sweet and sour, only remotely useful for lubrication... sike! their chunky flesh makes even that a horrible use! plasticky skin, with liquid interior make them a nightmare to cut and use, with skin sticking to the top of your mouth!!!
Add more criticism in comments
side note, is there shipping for the 3d printer all around the world? i kinda live in asia...
Dude this is amazing problem solving and creative thinking!
** Suggestions**
- Design a little longer contact patch with enough for polishing to seal
- Go to 4 flaps
- increase motor size by 3% & and adjust flow rate accordingly
😀
When life gives you air, you make an engine. I’m over here just breathing like a chump
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?
Dude!! I've never heard an engine that sounds like that!! Amazingly accurate!
You should make an radial lip seal that closes in the axial direction towards the bearing as part of the front of the transparent housing behind the bearing. Or an axial shaft seal. .
Or just fit a regular old oil seal there like all vane motors have had for the last 100 years or so.
That is SOOOO COOOL PLEASE proceed to iterate on this flappy-engine!!
I love it :O
I can think of 2 things to improve the design.
1. I think redesigning the flap and pocket that it sits in could help with torque. The air is "pushing" on the flap like a lever, but if the flap is not strurdy, then it could be like trying to push something with wet speghetti. You could design it so that the pocket the flap sits in is where the mechanical leverage is applied, and the flap acts more like a valve than the crank for the air to push on.
2. You can try to make the housing one solid print that you do not assemble. So you would print half of the housing and then pause, insert the crank wheel, and then continue the print. So, when it's finished, the housing is one solid piece that you don't have to seal up. Try to take advantage of the flexibility of 3D printing more.
For good side sealing use 2 O-rings and add flaps to your flaps. Love the engine so far!
Nice work on the SlowMotion sound effects. Especially the last one with Flappy.
Using a sealed bearing may help. Also going back to the 3 vanes (now flaps) would also help, as you explained earlier in the video, you are loosing speed by increasing the chamber size, so more flaps would give you more torque. If you can’t get sealed bearing, you may use a lip seal outside of the bearing. These vane motors normally have aluminium cases and graphite vanes. The vanes seal by air pressure that builds up behind them, but I have also came across a 4 and a 8 vane design with the rod solution. I think you have done a great job on this motor and the main changes I would try would be these, more flaps and a seal on the bearing.
Yes finally, i love printable vane engines! I think maybe you could improve it by A) reducing the space between the rotor and the wall, this reduces the air needed and may affect torque, but there is less area to seal, and B) doing so may allow using a small strip of flexible material like TPU to be inserted in a solid rotor, or making smaller compliant flaps like the last design. I think reducing the amount of movement can allow them to seal better (at 17:50 you can see the flap detached from the wall when the pressure went too low to push it against the wall) and C) maybe using a thicker grease to lubricate the engine will provide more sealing, just like engine oil does. Also it may be fun to experiment with the number of flaps. I've always wanted to try printing one of these, thanks for sharing this Joel!
I'm only slightly disappointed you didn't smash a tomato with it. Tomatoes are disgusting. :D
Also, if you want to maximize performance, try different propellers. rctestflight's boat propeller contest really showed how important it is to match the propeller to the torque/RPM curves of the motor/engine. Reducing the space between the vanes and rotor will decrease torque but increase RPM, so you can compensate for that using a different propeller.
Maybe make a cylindrical cutout in the cover where the rotating part of the engine slots in, then you could make a flappy seal inside the cutout so the engine doesn't leak as much air. also you could try graphite powder for lubrication! In my mind a powder also reduces leakage because the particles block some of the air?
The flap concept is really cool, more flaps, and playing with the rotor to flap size ratio would be really cool to see!
optimization:
1:a 2 stroke expansion exhaust would be perfect as you are running within a small rpm bandwith. additionaly positioning of the exhaust is key.
2: take advantage of the centrifugal forces on the ''flappy'' valves. Give them more weight to allow for better sealing
3:silicone the living *tomato* out of every gap (at least on the outside/housing)
You made a great job! Wonderful video!
Hey There!!
Instead of using flaps that bend and break, consider incorporating cavities in the central bearing that align precisely with the pressurized hole during rotation. This approach allows the rotor to be centered to the outer bearing, ensuring a better seal. It also enables you to optimize the volume to the intended pressure that maximize efficiency and duration of flight.
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....
I would love to see an engine with multiple staged chambers, like some water pumps. The waste air could be used back and sent to the second or third chamber.
It might be an insignificant detail but the actual anagram of ''Tom Stanton'' is Tomato's TNN.Anyway to add to the topic of the video the leakage can be mitigated(even possibly eliminated?) by altering the design to add side and apex seals like these on the Wankel rotary engine on every point of contact between the rotor assembly and the housing but this would add complexity and manufacturing properly toleranced mechanical elements of this size is itself alone an engineering endeavor.
This man is the start of my engine engineering journey
Some genuinely impressive engineering!
Make a turbo Jet engine from Metal 3d printed parts
I love Jet engine so much and also watching you with Jet engine
I love how you realize that Tom Stanton actually decided to go for the most efficient engine he could make at that time. I hope he takes your flappy engine and continues making the airplane once he settles on how to regulated the pressure (because the piston engine basically limited the air use).
very interesting design, i might recommend that you add a circular flap/seal, angled slightly outwards, so that the engine would seal from the shaft and automatically adjust the tension by air pressure. very cool concept and i hope you get it optimized.
Ok. Integza spoils us with a video. Time to crack up a bag of chips.
Use babbits or graphite as the housing material to reduce friction. Also try recessed reliefs on the flat side to reduce leakage. Kinda looking like a dove tail type joint.
You can try with different propellors with other sizes and angles as the optimum propeller is different for each type of engine.
That flappy design is pretty cool. I was annoyed at first because I don't really like vein engines and all their potential problems, but you solved a lot of them by keeping it one piece.
I love integza and Tom . Best 3d engineers on UA-cam, have a lovely Christmas and New Year integza and Tom .
If you were to print the flaps in the extended position, then you wouldn't need to rely on centrifugal force and the pressure to extend them to the crank case. This probably would increase low rpm and low pressure performance I assume.
Suggestions
1. Making the ends of the flaps thicker so that they don't get worn out
2. Making this flap sticker will increase the centrifugal force thus the flaps will get closed faster and there will be more pressure difference between the both chambers
3. And although you may also decrease if possible the radius of the of the rotor so that its moment of inertia decrease also you get more area upon the flaps show more force
Also making an engine out of ice can workout in liquid nitrogen if possible then or else in case you can use nitrogen or liquid nitrogen as the compressed gas 😂😂😂😂
Make the engine using carbon fiber or metal 3d printing(much harder) or just ceramic as u did in the Aerospike rocket engine video it will be much more durable and don't forget to lubricate the engine with graphite(pls like I really need a 3d printer the one at my school sucks it takes 2 days just to print something small and services are super expensive)
For longevity, there are similar things to that "flap" built into the back hubs of bicycles. Meant to only apply torqe in one direction so your pedals won't go around all the time. There are things you can borrow from such designs, such as small springs instead of that plastic that must wear out to metal parts with low friction oils.
I remember graphene being used to reduce friction, perhaps it could also help seal the engine better and further increase its efficiency.
I don't know if you wanna invest more time in this project, but i do think that a harmonic transmission should help a lot. If you take time to 3d print one so it has less weight than a metal one for the plane and then put more flaps in the vane engine which will create more torque so the transmission converts it to more speed and then manage to regulate the pressure it should greatly increase the succes of this project. I really hope you try this!
Awesome video! Much appreciated 💜
For the side issue to the bearings, the Labyrinth seal is your choice to go the hing design is a bit to flimsy for longer runs like an hour or more but if you aim still for a few minutes thats fine. Your enclosure also would be good to be done from teflon, because teflon on teflon reduces friction even more. And to increase the torque it would be good to increase the diameter of the rotor as this is the lever in the equation. Next in row would be the surface of the flaps. Best regards Michael
I forgpt, polished surfaces reduces wear and tear which causes friction. So polishing like you did it with the paste is also needed.
Tom Stanton is actually short for Tomato Stanton so good catch there! Also I recently saw someone build something similar but they machined in these 'cooling vents' throughout the casing with the purpose of redirecting escaped gasses back into the chamber!
Make the air leak path through the flat side of the engine go in a zig-zag. I think using the abrasion until it fits method will work fine here
Cool vid! Try encasing the bearing in the plexiglass. You would have to get a thicker piece. And think of a better sealing for the rotor axle.
Some ideas on trying to make it better... The leakage out of the front plate. The only way to do that I think would be an oring. But an idea would be instead of a traditional rubber oring. which would need a little oil to reduce the friction, maybe try one out of ptfe. or essentially machine it into the design. Like instead of having a flat boss have a ring of ridges that are high enough that can be compressed slightly then using the lapping compound will help in making it a tighter fit. It needs to be a circle so it follows the same grooves.
If you want it to be a wear item just machine the groove into the face and either make or buy flat ptfe orings.
Also now since you have removed the need of using vanes and instead using flappers. Maybe try multiple flappers?
With planes they need to be light, so if you want to use it for an airplane you will need a very light pressure regulator.
My suggestion is, move the seal. You need to seal around the bearing. To reduce the friction force, you want the seal as close to the center of rotation as possible. So move the side seal (which is currently located around the perimeter of the rotor) inward to a ring with a diameter just larger than the bearing. But, you will need to connect this inner ring seal to the flap, which you can do with a thin extension from the ring to the flap... like your apex valve, but on the sides of the rotor. Do leave all of the material of the rotor (except for the seal) in place to take up volume. The less volume your expansion chamber has, the less air is required to raise the pressure.
graphite powder to lower friction and fill gaps, o rings on parts that arnt moving, frount pannle with o ring to tryt and close off the bairings, you can use lose oings on the flap parts as the air presser can over come the small bit of frishion, a shaped nozzle
Hi Integza! Love your videos. My thoughts go directly to planing the surfaces between the casing compartment of the impeller and the transparent plastic covering, maybe with the impeller assembled during the process to ensure the tighest fit without friction. And perhaps use a teflon lining inside the casing.
Love your videos and its a great little engine, respect to Tom. He is also a brilliant engineer.
The usage of teflon is so cool. I think the obvious next step is the airplane. Some kind of your own 3d printed presurre valve for staying light weight could be interesting.
Make a gasket, the diameter of the housing, and spray with silicon. Seat the gasket beneath the outer wall of the motor. You lose your visibility, but seal the unit.
The improvement I would suggest is to replace the current bearing with a sealed one. That way you stop the air from escaping to the outside and hopefully this will "plug up" all the other leaks aswell.
Luv Your Experimental
Designs 🎉
I thoroughly enjoy both this channel and Tom's - send the engine to HIM. He's got plenty of experience making ultralight models that fly on modest power.
Tomatos are excellent. You just haven't had the right one yet.
Finally, another upload from you!
Vent the exhaust into a second (smaller) motor of the same type to more efficiently use all of the air pressure. To make a better seal against the top and bottom of the motor, use a rounded surface on the top and bottom of the main rotor and sand a concave divot using the the rotor in the same way you explained in the video and use bearings that have ceramic or gem balls along with a seal over the race.
try with 3 flaps for extra power, might help get more lift in the plane. and maybe u can try to use graphite to lubricate?????
You could use permanent magnets to couple the output schaft with the flaps in separate sealed chamber.
Good luck with it dude!
Adding more flaps would be good since you don't have to worry as much about the sealing. Maybe it would be cool to compare the engines with the different numbers of flaps too.
Also seemed like at slower speeds the flaps don't press against the walls very well. Maybe you could print them in a more extended position so they press against it more? Might be another compromise with friction though, but could mess with and find some best angle.
maybe some high tension elastic bands around the bottles that will squeeze them as they lose air to help maintain a constant pressure to smoothen out the blade speeds.
Once you moved from vanes to flaps, I had two thoughts
1: wouldn't more flaps add more power output? Try six flaps. And that should also limit the wear and tear on each individual flap.
2: I remember reading way back in the day that hot-rodders (not sure that translates across languages and times, but people who built or modified cars to make them go faster beyond legal limits) discovered they'd get more power out of a car's engines if they modified the piston heads to be cupped instead of flat. Maybe put divots in each flap to catch more air?
Really interesting progress on how engeneer résolve problem.
My think is to create a rotary chamber with vein to limit leaks.
Like the support for 3D printer filaments.
Cool video! An idea to improve it: changing the transparent cover for Teflon as well, it seems to leak above and below the rotor/flaps
The concern I see with the flappy design is the very thin section of material doing most of the flexing. For longevity I would make that thicker and put the base of the flap deeper into the body of the rotor. On the subject of sealing, a couple of thin O rings on the bearings would probably prevent leaking through that vector. I would also look into how much the flat front and back plates are flexing under pressure because even with the O ring, if those are deforming you're going to lose air that way.
Put more flaps in it. 3 or 4. Also, put channels in the body to put in rubber O rings to help sealing everything.
a new integza video woooooo
@Integza Loving this style of video!! Maybe add a small pulse jet engine on the rear when you eventually get it up in the air. If you have a controller you could always start the engine up mid flight for a boost and sound amazing.
Great work! Multiple stages would increase the amount of energy you can extract from the air, and leakage between stages is an insignificant problem compared to direct leakage without any work done.
Measuring the exhaust temperature should give a good indication of relative efficiency, as pure adiabatic expansion even from just 2 barg to atmospheric makes air really cold. But, it would be a rough relative measurement for such short runs, as the air heats up from heat in the engine. But it could be useful to evaluate change in efficiency from minor changes, as long as the initial temperature of the system and other factors are about the same in each test.
i think you should consider the expansion ratio of the gas in the chamber and see how much it expands and what the pressure is when it's expelled. if it's not the same as the atmosphere, you're wasting efficiency.
the seal between the inner cylinder and the outer cylinder is good for the flapy engine but it sounds like there are still leaks between the front and back face and the spinning cylinder. you can try incorporating a mechanical seal mechanism to try to alleviate this but i'm not sure how it'd work.
another idea i had is to make everything out of a very hydrophilic and low friction material and have some amount of water in the compressed air bottles so when the air gets injected, it carries its own lubricant as well as providing a potential seal with water. not sure if this'll work at all.