I built a FLAP ENGINE (New Rotary Design)

3D Models
Materials

Machines

#rotary #engine #3dprinting

[naasking]

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.

[RogueWolf_]

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.

[jkainoal]

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!

[calebhudson]

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!

[TorqueTestChannel]

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.

[joeg]

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.

[diegogermanacosta]

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.

[studiowilds]

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😂

[somanshukumar]

There is nothing sacred to him.... everything is a rocket for him

[astrospox]

make the engine housing from another material that is harder and lubricate it with graphite

[LeVraiPoio]

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.

[birgerjarl]

Improvements:
1. Design the dimension of the enigne such that the exhaust pressure is atmospheric
2. Make a simple radial shaft seal with an o ring
2. Remove the bearing in the back plate to reduce leakage and friction. One bearing should be enough since the propeller will balance out the rotor.
3. Optimize for thrust integrated over time (impulse). A too long run time might mean that the propeller is running at an unefficently low rpm which will show up in result as lower impulse

[ryukomat]

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.

[foodini]

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.

[zowkarol]

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!

[ralphmay]

13:29 "Teflon, which is the thing in your non-stick pan" Proceeds to show us a cast iron pan.

[kogger_tech]

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.

[swiftarrow]

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.

[sketchybmxer]

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. 👍🏻

[MrAlanCristhian]

The connected vains idea was a display of ingenuity.