At least he's not afraid of his own voice, like some people are. This is normal, only because we don't sound to ourselves the same as all other people hear us when we speak. This is because, what we hear when we speak is modified by the acoustics cause by our head and our own bodies. When other people hear us speak, our voice is not modified as much by the acoustics of our head, therefore we sound differently to others than we do ourselves.
He has the posture and the behaviour of a university professor. I really like the way he explains. I sometimes try to copy his approach and tempo for my lectures at the university. I get critcised a lot for trying to upload all as fast as i can and not letting listeners to catch up. As for the voice - there is a voice coaching technique that can be studied.
Thank you so much for your video! I am a Professor in a Polytechnic School of Engineering In Spain, we are developing a PHD thesis in this field with an hybrid system of much larger power supercapacitors and a pretty complex converter with three control loops. I just wanted you to suggest to change diodes by MOSFETS and use syncrhonous rectifying, you will increase efficiency of conversion. Your videos are terrific and the way you explain perfect 8-). I have recommended your channel to all my students. Best regards from the North of Spain and thank you again for sharing your knowledge.
True, way he explains things makes even average joe understand the topic, least on basic level of what is going on. For instance i didnt have clue about magneto hydro dynamics before, let alone even knew this field existed, but now i have project going on using this technology... Though it would be nice to ask few question from him regarding this topic and application of said tech.
Many years ago I worked on an Emergency power generator for aircraft. It used air to rotate a 3 phase brushless generator running at about 100Krpm. Very small, the rotor was no more than about ¾” OD and the length was perhaps about 2”. There were two of these in the case and air was pumped into it through a hole that was the diameter of perhaps 24AWG wire. A disc on top of the rotor with tiny little cups to catch the air was used as the method of rotor propulsion. The combination of the two generators produced 3KW of power at about 115 Volts and ran and used the air as air bearings in addition to just propulsion. Perhaps you can use this method but instead of generating power and then running a motor just cut out the middle man and run the motor directly with compressed air. I don't know how much power you need but I believe this combination of air tank and motor will be much lighter and less complicated than 2 two-stroke motors and mufflers and generator replaced by just an air tank. So even your motor becomes simpler. Just driven by air, no copper windings, but of course you will have to make the motor to run on compressed air.
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What you describe is great. 100.000 rpm!!!!!!!!!!!!!!!!!, that's too much even for an aircraft turbine 8-). The idea sounds really atractive but, as you have told, the problem is compressed air. Our prototype is for a PHD Thesis (our aim is to obtain above 7 kW at 50V). We are trying to use ultra capacitors, no batteries, active rectification a DC-DC controlled converted and several control loops to the thermal motor (first carburation latter injection) in order optimize fuel consumption. Thank you sou much for your answer! Have a nice weekend.
Looks like he is talking about some sort of EDF before they arrived to the hobbyist market. : Generally, most EDF units will run between 35000 RPM and 50000 RPM. www.radiocontrolinfo.com/rc-planes/edf-jets/edf-brushless-motor/
These videos are the reason why TH-cam deserves to exist. There's a lot of content out there, but these videos spreading your engineering knowledge to the masses are incredible.
A lot of his video's go over my head, I start to wonder if I am being Turbo Encabulated. (Watch the video if you havent, Dave Rondot has a one but there are many, not all of them are well spoken but there are several that are! :)
This is very interesting. I haven't seen discussion on hybrid quadcopter power systems elsewhere, and this guy is so incredibly precise but clear in how he explains things. A remarkable channel.
If anyone is going to build the first publicly available anti gravity/time displacement/space distortion device and/or machine, its this guy. Thanks for the videos. Your comprehension and explanation of mechanics, electronics, and pretty much everything is far beyond mine.
I've daydreamed of using a brushless RC motor as an alternator for a hybrid aircraft. Thank you for testing and greatly refining it's use, and concise explanation. As usual, well thought out and researched. Well done!
I once did a test flight series that had much of the same torsional resonance problems, that you described, which I discovered after about 4 hours of flight. The propeller developed a green stick fracture and the ensuing vibration caused extreme damage to the aircraft. Namely, the canopy partially detached from the cockpit and ended sitting in a vertical position on top of the left wing, which caused the stall speed to double. The aircraft stalled 3 times before I pancaked into the ground. The builder had built the 3 piston drive system with no buffering of the tortional resonance. You described the cause and effect of this extremely well. If the builder had installed the drive system with a belt/pulley arrangement as the designer called for, the propeller would have stayed intact and the aircraft would still be in one piece. Keep up the great work. Respectfully Rick Mason
I'm having problem to find the words thanking you enough to share these experiments. I really do appreciate the work and effort you're committing. This is one, if not the most educational channel.
I owned many engines when I was an active R/C-er and Saito engines (pronounced "Sigh-tow" in Japanese parlance) are among the best in the world in my opinion. I met Mr. Saito about 20 years ago in his factory in Chiba, Tokyo when a friend and I interviewed him for a magazine article on his engines. He was very gracious and full of information, and though quite old then, was still actively engaged in designing four stroke engines for the R/C community. He was also deaf as a post having stood next to running engines studying their operation for far too long and far too often. He admitted that if you want to keep your hearing into old age you should wear earmuffs when running any R/C engine, particularly the larger ones at full throttle, as even muffled engines at close range can cause hearing damage. In the air they sound wonderful, but that's where they're designed to operate, not a few feet from your ears on a wooden test stand.
Stumbled on this video with no interest at all and stayed for the whole thing! Great straight forward explanations and cool to see how inventive you are.
Why did i losed so lot of my lifetime before finding your channel ?!! I'm a technician in metallic construction, I like your work and you really make me appreciate mine, thank you .
I am only now begining to see a couple of whole projects. I was scratching my head, and wondering how it all relates, then boom... Thank you for your work, and seeing your drive, is helping me get back to my tinkering
He doesn’t look like the type of guy to win a bareknuckle tournament at your local pub, but if you beat him up he might just fabricate a terminator that can simultaneously beat up every competitor at the following tournament.
I know you've been through a traumatic (physical and emotional) experience recently, but we always loved you when you were so (geeky). We would love to have you as a college professor explaining how the world works. I think most of us have been through University, and understand there's more to learn past the classroom. Thank you for everything you're doing!
It took Harley-Davidson almost 100 yrs before they balanced the crankshafts on their motorcycles. However, in the aerospace industry it wasn't long before they started balancing engines, because it was much more problematic to have an unbalanced engine in an airplane. Someone did a bit of work making up the mounting fixture for the engines and generators. Also, I have an Engineering Degree and 2o yrs experience in Aerospace and I'm following along with everything. Then I think does anyone else have a clue what you're talking about that doesn't have some Mechanical or Electrical Engineering background ? Great channel I hope it inspires younger kids to put down the video games and start experimenting. We need to give the kids the resources too.
Thank you for the quality content and a lot of explanation with examples on practice. English is my third language but still, I can understand you much better than my several native teachers of physics in schools. Well done both of you!
Thanks. I noticed that the current with the batteries was about 12 amps and 366 watts while when the two strokes were running that going into the same load was only about 300 watts and 8 to 9 amps. Those load resistors look like they may have some inductance and this may suggest that you are dealing with more AC from you generator than perhaps you are aware. It would be good to scope the voltage across the load.
For some reason I was expecting an audio related drone generator (think raga). Not a generator that happened to go on and power a drone... But hey, this was cool too so I watched anyway!
I know. The switching from the ESC that starts the engines to the low resistance, high current input to the rectifiers is challenging. Any specific suggestions would be helpful.
Tech Ingredients Hi, I may be wrong but, my guess is those retrofitted mufflers you made would work great for 4 stroke, but I suspect they will get clogged with oil and back up the engine.
Using active rectification gives you an easy way to use the rectifier board as a driver for starting the engines. There are just a few extra FETs used to redirect power to bypass the output regulator and drive the BLDCs to start the engine(s) using the rectifier FETs. The catch is that if you have an optimal drive ratio to couple the engine to the BLDCs, you do not have an optimal ratio to drive the engines for starting. It is likely that you'd need a transmission to provide these two different modes.
It would be very useful for a drone to be able to restart the engines in flight. I'm assuming that a stall for a typical drone allows the batteries to supply lift for a few minutes while the engine(s) are restarted. Optimizing the restart could be kind of important. If the generator/motor set has to work through a gearing ratio that is not optimal for starting, but is optimal for power generation, then the whole mission is a fail. Based on my studies, the transmission ratios for optimal power generation are not 1:1 (They could be but I have yet to see a commercial BLDC that could support that and be weight competitive). So their would need to be two gear ratios. One for starting the engine(s), and another for power generation.
Very impressive. Very interesting. I really enjoy how you explain all the thoughts and technical parameters about the way it works in general but also about details, what you need to know in order to optimize the efficiency and the overall usability of such an epic generator. And all the background about energy density differences between LIPOs, 2 stroke and 4 stroke engines and ways to compensate voltage drops caused by (virtual) internal resistence during heavy load, you did that very good in my opinion.
For a gasoline quadcopter, I wonder if it would be more efficient to use the engine directly with a prop to generate some baseline thrust, with the electric motors providing the additional thrust and manovering. Also, for teh generator, you can probably get some more efficiency, and probably also a bit less less weight by using synchronous rectification with MOSFETS instead of diodes.
When you use multiple sources of power (hydraulic and electric, or combustion and electric), there is a higher mounting hardware cost to route the transmission of fuel and power to the different outputs. It's the intersection of the utility line puzzle with the square-cube law. The additional hardware weight would probably counteract potential efficiency gains in copter designs due to the existing complexity.
@SuperAWaC No, IGBTs are more robust and have higher power ratings (but a power rating of a semiconductor is the rating of how much power can be wasted inside of it before it releases the magic smoke) than MOSFETs, but not more efficient. An IGBT has a constant voltage drop of lets say ~1V (more or less depending on current passing through), while MOSFET has a constant resistance (also depending on current passing through, or rather the temperature of the die, it has a positive thermal coeficient - so higher the temperature the higher the resistance, this is a desirable characteristic for powersharing with parallel active devices). There is a crossover current when IGBT will be more efficient than a MOSFET (depending on types of course), but usually MOSFETs are more efficient. For example a low Rds(on) (3mOhm) MOSFET can carry 330A of current before it's voltage drop reaches 1V, so unless you have a higher current flow a MOSFET is more efficient than a IGBT.
Wonderful job so far. I love your scientific methodical approach to this project. As an Electrical Engineer, I have followed your work with ease so far. You are doing a great job of determining the parameters of your engines and generators to suit your needs nicely. Your component choices are also very good. Now, I'm going to watch your next video and see how the next phase goes.
As a fellow EE I am surprised by your assessment. This is never going to work. There is at least one fundamental flaw. The concept of constant voltage is doomed.
Great high-level lecture. Simple, Precise, and very instructive. Very Solid Knowledge of what he is explaining. I end richer after seeing this video. Thank You
Thank you for your excellent video. Years ago I considered buying a lightweight generator, and had a brochure on it, which is now gone. It was called a Lightning Charger, and came in versions that put out 12 volts DC, 12 volts AC, and 120 volts AC or DC. It was powered by a 2-cycle engine, and what made it light weight was a patented permanent magnet alternator that put out about 55 amps. I communicated with the inventor about the charger's speed control. I just looked through old emails and found one from 2004 from Coleman Powermate, which had purchased the technology, answering my question on where I could buy one. The answer was, "This unit was discontinued and was not sold to anyone else." The generator/charger disappeared from the market. Years later I came across a document on the Internet that was about the Department of Defense appropriating the patent, which said the technology was needed for drones. If you can find details about the alternator used for that generator/charger you may get ideas on how you might improve on your design. However, just guessing from the look of the size of your design and its output, your design may be getting more power for the size and weight than the Lightning Charger did. If so, the DOD may ...
That is a bit of a reach. He hasn't invented anything new. Just adapting old ideas to his application. Search "APU" and you'll find plenty of examples of a very old concept. That said, he does do nice work.
Been in aviation for 40 years Recips , Rotorwing and Private Jets for the last 21 a lot of moving parts there and a lot of things that could go astray with RC parts obviously this guy is a Electrical Engineer and very well done and thought out !
Yeah, he sort of made it sound like having to deal with three phase, instead of single phase, is a bad thing, but is actually better for smoother output, lower vibration, etc.
@ Jay Dee A full bridge rectifier is just diodes arranged in a manner as to take advantage of the high and low peaks of each phase. The reason he said a 3 phase motor would need 6 diodes is because it's arranged in a "Full Bridge" configuration. You could actually get away with three diodes per motor/generator however you would be wasting 50% of the power.
Yeah. I guess to store the charge. But isnt the output from an ESC basically AC? But even then, there's fluctuation in all motors. Lol. So you have to generate it, rectify it, store it, and convert it back again. Right?
This is THE most informative, best explained video on UAV hybrid power I've seen. Thanks to all who produced it, and made it's complexity easy to digest: you have one very happy new subscriber!
Two stroke engines run with specific exhaust pipe back pressure cutting or changing the exhaust pipe is like changing the cam timing on a four stroke it might work on a small engine but should not be done !!!
Thanks for some great introductory explanations using your uniquely engineered power supply. The next step would be to investigate the efficiency of the system. You need to put the fuel tank on a non-vibrating surface with a scale to calculate the fuel consumption. From that it's a simple bit of math to get your power efficiency. BSFC (brake specific fuel consumption) would be useful in finding the optimal load for any given rotational speed, load dependant. For the muffler system, I would strongly suggest optimal design software like Virtual 4-stroke to get more specific parameters to run your engine system. It'll help optimize exhaust and intake design by specifying targets like BSFC or power. Could you post the weight of the entire setup and also include the cooling fan load when computing efficiency? From your previous video's I figured you would have designed a cooling system that was mechanical to mechanical (direct drive fans). Future work perhaps? All in all this looks like a fun project and one that could help with understanding thermal loads. Your alternators would be getting pretty hot if run at a constant duty cycle. Thermal camera footage perhaps? Thanks again for showing off your work with patient explanation!
Many years ago I worked on an Emergency power generator for aircraft. It used air to rotate a 3 phase brushless generator running at about 100Krpm. Very small, the rotor was no more than about ¾” OD and the length was perhaps about 2”. There were two of these in the case and air was pumped into it through a hole that was the diameter of perhaps 24AWG wire. A disc attached to the shaft just above the rotor with tiny little cups to catch the air was used as the method of rotor propulsion. . The combination of the two generators produced 3KW of power at about 115 Volts and also used the air as air bearings in addition to just propulsion. Perhaps you can use this method but instead of generating power and then running a motor just cut out the middle man and run the motor directly with compressed air. I don't know how much power you need but I believe this combination of air tank and motor will be much lighter and less complicated than 2 two-stroke motors and mufflers and generator replaced by just an air tank. So even your motor becomes simpler. Just driven by air, no copper windings, but of course you will have to make a motor to run on compressed air. Since you also want to control the voltage, you may also need a PID control for an air valve which is almost nothing. I also designed a controller with a 1KHz bandwidth for a hydraulic valve for aircraft control surfaces. Just 1 Amp for the control valve. Perhaps you can find a simpler way to control the air flow. What is your response requirement?
As an electrician; I Love the way, you explain things, mostly understood by an electrophyte...I know what you are explaining.. Right now, I'm playing around with Maxwell Capacitors...Dont try it folks!
Did you mean a winkle engine, as in Mazda? Or for that matter, why not a reverse polarity magnetic rotary engine lol A wink or a nod, it's all the same to a blind horse
Great video! I thought up the same idea of using a generator to power a drone. Because I was thinking of a way to use engines to make a drone. I figured it would be impossible to use engines to directly drive the propellers, because the speed of the engines could never be controlled fast enough. It's nice to see someone actually doing it. Another benefit of using gas, other than more kiting capacity and longer flight time, is being able to just refuel to keep flying. Other wise you would need to wait for your batteries to recharge or have multiple spares. Even with the cost of building that system, it's probably still cheaper to fly all day than it would be to have enough spare charged batteries to fly all day. That the reason I love my nitro car, I can drive that all day. If it were electric I'd get 10 minutes of play and then would have to wait a couple hours for my batteries to charge.
It doesn't take a couple hours to charge a lithium battery pack today. A 5000mah 3S lipo battery pack will run my brushless electric 1/10 scale, dirt oval, r/c car for about an hour, and it takes about 45 minutes to charge the pack. I can run all day with only 2 battery packs. I have nitro 1/8 scale cars also, but brushless electrics have come a LONG way today.
It's so crazy how you are doing all the experiments I have needed for my projects. Have you considered using VESCs (vedder electronic speed controller) in replacement of the rectifier circuit? More expensive solution, but you can start the motors with them (useful in failsafe situations), and may get better efficiency than a rectification circuit. You can also get accurate RPM readings from the VESCs allowing you to more accurately control the throttle. You could even write an algorithm that cuts back on the power generation voltage through PWM inside the motor controllers when it detects the generator is bogging down, allowing less voltage sag under heavy generator load. The two engines could also be decoupled mechanically if you used an encoder with each VESC and set them to run at the exact same RPM with the same encoder offset. (it has the processing capability to do this accurately enough I would say to be just as good as a mechanical linkage) This would allow for the same balance that you currently have, but less mechanical hardware, and more importantly redundancy in the design. Two fuel tanks, two throttles, two everything. Redundancy is always nice when you have expensive equipment flying in the air lol. A boxer engine setup may further decrease vibration and may eliminate the need for counterweights on the flywheel.
Check out my TH-cam channel, I had the idea to use a VESC as an active rectifier after I built my skateboard. I ran an experiment yesterday and it was promising.
It was good to see your evolution from the 4 stoke to the two stroke engine and all the explanations leading up to .it’s interesting problem solving stuff .thanks for the vid
Love your videos and the technical accuracy (correctness) that you demonstrate. I am working on a gas powered quad, and found the same thing you did regarding torque pulsations. I moved from a 4 stroke engine to a 2 stroke. Also added a flywheel to minimize amplitude of pulsations through my transmission. The 2 stroke runs well at higher RPM's, so with greater gear reduction, this also enabled a lower torque (at the engine) for a given amount of power. Still had some problems during accel up to operating speed of resonance on the soft motor mounts, but not enough to ruin anything. Did have to go to a carb with diaphragm pump, not float, due to the high level of vibration.
Thanks and interesting. Our vibration is very low, but in an airplane installation, the vibration should be at least as high and probably higher than yours.
I think some Maxwell boost Caps or supercapacitors will greatly improve the setup and also allow you to reduce the size of your battery packs and still maintain of a set time limit if you have mechanical failure to get the Drone under the ground safely.
A fine tuning of the energy storage system, by topping off the lithium ion batteries with super capacitors might be useful. The bulk of the energy back up will need to remain in the batteries because an emergency landing could take as long as a couple of minuets and the energy density of the batteries will be more important then the power density for this kind of time period.
Tech Ingredients the reason why I thought of it is because people are actually replacing car batteries and testing with supercapacitors and having better luck than a regular battery and they're fairly light. They have a super low internal resistance they charge almost instantly. Now the number that you would need to get to the voltage that you want may make it unfeasible but as the technology gets better and better eventually batteries will be replaced.
I'm aware of that application in starting automobiles and it makes sense. The actual number of joules used to start a car is really quite low and far lower than the energy storage capacity of lead acid batteries. It is the peak power requirement that has determined the sizing of automotive batteries and so with a super capacitor to supply the peak power a much smaller and lighter battery can be used. Batteries are improving as well. Magnesium ion batteries may begin to make an appearance with double the energy density of lithium ions and of course, fuel cells are getting closer and closer to realistic availability. We'll see.
I have watched a few of your videos, very informative, you must be a professor, but definitely experiments for people with brains or who use them, I appreciate it thank you for uploading, I'm in the field on the electrical side so I understand most of the terms and explanations.
Please complete this project. This one brought me to the channel and you start a LOT of project, but they just stop and aren't completed! Please finish, theyre so interesting!
I have watched some of your videos. You are the best teacher I have seen in my life. Not too much, not too little, the in-between reached. Teachers should be like you, then we would have paradise on our flat earth.
@@MrBobWareham @ 10:30 he talks about locking the engines 180° out of phase, and having a continous power stroke, so with that setup they would be 2 stroke engines. Plus, the sound. They're 2 smokes.
Yes, the chamber volume, exit coss-sectional area, etc, do significantly affect the engines power delivery. He didn't mention tuning the muffler, but knowing the detail involved in all of these videos i'm guessing he did the maths.
Wow a TH-camr with actual knowledge of what he is talking about!!!! quite enjoyable Whats the watts per Kg and watts per Volume (Power density) fuel conversion efficiency
Interesting. Every small engine I've worked on did have a counterweight on the crankshaft though given how close to the center of the crank they are they probably don't completely offset the static Wright of the piston and conrod
Another great project with solid engineering and again I can't help myself from making some friendly suggestions: 1) I think you're paying an efficiency penalty by pursuing the anti-vibration goal. 2 small motors will be less weight and fuel efficient than one large on producing the same power. Perhaps there are other ways to deal with the vibrations such as isolating the motor/generator from the flight controller? 2) I saw another hybrid drone project that used a propeller on the internal combustion engine to generate most of the lift for the drone and then use a lesser amount of transformed electrical power for stability and control motors. You kind of already need a big propeller to deal with expected cooling requirements of the I.C. engine. Saves the conversion losses going from mechanical to electrical 3) I don't think you need your capacitor bank if you already have to have the battery packs. Think of the batteries as "super" capacitors.
Very useful. Request you to kindly show the detailed video on how to make the generator assembly (complete), including the 2 motors placement at 180 degrees with weight offset balancing. I am working on the hybrid power unit,. your consideration would be a great help for me.Thanks with regards
THAT IS A HORRIBLE REQUEST. DID HE SAY ANYTHING ABOUT OPEN SOURCE? WHY WOULD HE SHARE THIS INFO? WOULD YOU SHARE ALL YOUR INFO WITH HIM? WOULD YOU PAY FOR IT? WOULD YOU PAY AIR FARE AND LODGING TO GO WORK WITH HIM FOR FREE? NO? OK THEN, BUZZ OFF MAN.
I mean, if there is a problem with what darpan asked for, all he has to say is "no I dont wish to share this information" or they could work something out in a more private manner. So there for your two comments in all caps were are still are unnecessary. Have yourself a good day :)
Mc cc: I am not going to comment on the intricacies involving intellectual property. What I am going to say is that you are absolutely not entitled to make either a moral judgment on a request for more information, nor are you entitled to tell tech ingredient what he will or will not divulge about his ideas. Darpan: the concept seems relatively straight forward to me. It's basically two engines mounted next to each other in the same plate; then synchronized with an ordinary timing belt and sharing a control solenoid. I actually see a few similarities to Edison's original generating plant; where they had to synchronize the two generators, so the faster one wasn't driving the slower one.
You have an incredible presentation skill. I know many people who are excellent engineers or great presenters, but very few people who are both. I wonder how much power the commercial drones can generate - after all it's only around 300W or less than half a horsepower - probably not nearly enough to lift the motor with the fuel alone, not to mention the entire drone. This video shows really well how hard it is to build an efficient system like this, not to mention making it a working product, which is way harder than building a prototype.
It is my understanding that a tuned exhaust on a two stroke will increase the fuel efficiency and power by approximately 12-15%. We are using the DLE 20 single cylinder engines as well as the DLE 222 4 cylinder engines. If you have better information or a link to a source for a tuned exhaust that is compatible with these engines, please send us a link and we'll pursue it.
Love the project that engine looks very nice but I would have used a small mechanical fan driven from the main motor shaft to save electric with the fan thanks for the video.
I love your content. I can’t get enough of your videos. I am envious of your shop. But on a side note you should be in every high school science class across the nation.
If the concern prompting the hybrid solution is the higher energy density of gasoline versus lithium polymer batteries... why not just build a pure gas-powered multirotor? This way you would not have the losses and weight of the generator/rectifier system. However, to get around the insufficient response times of using individual gas engines in place of your electric motors... use a single gas engine running at an efficient RPM... and run collective (non-cyclic) pitch rotors. Your flight controller could manage the collective pitch servos and could provide the necessary responsiveness. For example: www.curtisyoungblood.com/legacy-product-support-curtis-youngblood/attachment/stingray-500/
Well, you're right, but one purpose for a multirotor (and the reason of it's reliability) is to defeat as much mechanical links and failures which could appear trough them. If you want something with variable pitch props, and one motor, why not build a helicopter (proven design)?
Gas powered multirotor? Not if the power to an individual multirotor motor has to be adjusted 400 times per second minimum in order for it to stay level/hover
Multirotors vary the rpm of the individual rotors to provide directional (yaw) control. A direct-drive gas system is not responsive enough. Electric drive is the only way to go here. Less complex and much better control.
My brain is numb with information. Thank you for this video. I've been doing research on this type of setup for several applications I'm currently designing.
This is simply stunning engineering, I know all about motors but not electronics, even though I do electronic repairs in vehicles. I knew about the timing belt solution and the issues with twin cylinder two strokes being in phase, but the whole assembly is genius. You do so well at teaching, kudos to you Sir. I hate those Saito four strokes, give me a two stroke any day. The idiots at the flying field were real proud of their Saitos, but I suspect I was getting more thrust out of my 10cc Chinese two strokes than they got from their overpriced four strokes. Haven't been flying for a while, I need a new location for flying since something is screwing with my AFHSS system at the approved airfield. I didn't think it was possible to interfere with such systems, however, the nature of my last lost airframe made me suspect someone has such a system. Hitec makes a great radio, the Aurora is affordable and under normal circumstance is flawless. I look forward to you flying this new system, and learning everything you have to show. Thanks again...
This video kept popping up in my feed... and every time I see it, the image of a machine that just generates and releases a lot of drone just come up in my mind... and then in snapped back... ah, it's a electrical generator, not generator of drones... :P
Absolutely AMAZING video. I hope this turns into a documentary someday, and ultimately I hope your character in the blockbuster movie is played by YOU.
Yah! I was thinking the same thing.. like half of a Volkswagen boxer engine - the horizontally opposed piston setup should allow lighter flywheels. (I saw the comment that he thought of the boxer cylinder arrangement later but I haven't got to that part yet - just found this channel and it's great!).
Love the content as always, thanks for going in on the broken part.. you were moving in with the camera just as I thought "hmm, I wish I could get a closeup on the breaking line.." lol
You can filter out ripple by using a so-called „capacitance multiplier“ circuit. EEVblog has a video about them. They use a small capacitor, a couple resistors and a transistor. Since the transistor multiplies the effect of the filter capacitor, you can considerably reduce the size of the filter capacitor, which saves a lot of weight and space.
This is so cool. I've watched most of your other videos already and it's taken me a while to get to this one. Very impressive work with the drone generator and I appreciate the in depth explanation of how you balanced everything. The coupler that you broke could be replaced with a lovejoy coupler. Those, if you're not already aware, have a rubber dampening piece that separates the two metal halves of the coupler. They use them on cam driven fuel pumps on high horsepower motorsports applications because it removes the shock loading of the metal parts. I don't think that's the correct scientific term, it may be, but that's what causes it to break. Thank you for making these videos.
A hybrid system of this type is what I always dreamed of for my ultralight or airplane. That way, in the event of any gas motor failure, you have an electrical reserve to reach an airport. If the battery pack were large enough, it could also have incredible hybrid like fuel savings (which is very relevant to flight costs especially for a recreational pilot). This arrangement might also provide the incredible ability for some quiet soaring time (since stopping a gas only motor in flight for this purpose would usually be unsafe) since a restart would be assured. You seem like someone who would enjoy building/flying an ultralight as a project... I think a hybrid ultralight would be a thrilling addition to your inventions! (I'd be happy to help test fly it.) Thanks for all you do to spark learning, from a kids science teacher. :-)
I very much enjoyed this video and your teaching style is great. What you are building is a serial hybrid. As others have commented, the complexity and weight, and most importantly the conversion losses will overshadow the gains. Perhaps you should try a parallel hybrid. Use the engines to generate 85 percent of the upward thrust needed to hover the craft. Let the four electric motors make up the rest of the lift and provide control. You could use an inline pancake generator to supplement battery power, but you would be better off having no generator at all and simply sizing the fuel tank and the battery to have similar run times. I have been thinking about trying this for a long time. Counter rotation is the key.
There are arguments for and against both approaches. It is incorrect to say that the loses will overshadow the gains. For short flight times, the up front weight of the generator will dominate, but for short flights, the justification of either hybrid approach is questionable. As flight duration increases, the use of the far higher energy density of the fuel overwhelms the added mechanical weight. A modular, add on generator, is easier to incorporate onto existing multi rotors and is easier to isolate regarding noise and vibration, but it provides less efficiency than a parallel hybrid due to conversion losses. The purpose of the multi rotor will determine what is the better approach.
At the beginning of the video you mention the power density of batteries. You are correct when you mention the power density of batteries being much lower then gas. However, after building this whole system your power density of your gas system is much lower then originally estimated due to need for a engine and a generator. You also have a significant loss factor of your gas engine (generally around 30% eff) and a loss factor for your electronic components (probably around >95% eff). I'm sceptical if you can overcome the extra weight and losses and still have a higher energy per unit weight and volume when compared to the batteries. Did you calculate an expected expected energy density of your final system?
That's an important point, but the analysis has to be different. Unlike the batteries, the generator module is a fixed weight independent of the fuel quantity available. With little available fuel the energy ratio is terrible. As the fuel supply increases the ratio continues to improve and asymptotically approaches that of the fuel itself. The generator is a bad alternative if short flights are the goal.
@@TechIngredients I agree with your analysis. However, if you fix your system size and increase your available fuel the system will also increase in weight but not necessarily increase it's power output by the same amount. If I understand your goal correctly you want to produce a drone with a longer flight time then one of batteries. You are therefore need a specific power output to lift your system as well as the drone. If you increase your fuel supply to improve your ratio, as you mentioned, the power generation system will also have to increase in size to counter the increased weight. Thus there will be an optimal fuel supply amount and power generation size. This optimal may even lie much larger then you would think. Thank you for the response! I find your videos very thought provoking.
That's correct, but also applies to batteries when you factor in all of the lift system such as the mechanical strength of the arms, the gauge of the wiring, the motors etc. The engineering is complex and nothing is simply linear.
While I am a great admirer of your positive enthusiasm and your eloquent way of explaining such elaborate details of your generator. I don't know if you have considered that a drone requires about 100 watts per every pound, that is including the weight of the drone. If your generator weighs 50 lbs this means obviously you will need 5 kilowatts just to lift the generator plus you will need that much more power to lift the drone and I doubt that your generator will ever produce anywhere near 10 KW at 50 Lbs. If I were you I would be considering the design of a drone that would fly on gas, this way you will take advantage of 100% of it's power and avoid the vast losses of generating electricity to run electric motors... it is not impossible, I know that throttle acceleration is not fast acting enough to control the needed variations on each individual propeller but it can be done with a system of continuously variable transmission on each propeller being powered by one single engine.
You are totally right with the pulsing. This is true for any electrochemical process, due to the diffusion limited currents that are caused by the depletion of Ions in the Electrode region and the resulting low ion concentration surface layer(Nernst-Planck Equation (the defusion Part)). You just you just have to make sure that The overall surface area is large enough so that your net current is depleting little enough volume to be replenished during the relaxation time between the pulses.
For drone use, it is quite possible to use an ESC to start the engine. Some ESC units may have trouble with the higher RPM when the unit is set to slower than running speed, and thus overheat trying to apply brake. Contact your ESC manufactures for ones that can be used for starting and electrically disconnected when returned to idle. You do not want a reversible unit or one with a brake function. This may allow use in an enclosed airframe where access for starting may be limited.
Zach A did you actualy watch the video or read all of my comment? Patent the balanced special 2 cylinder engine he invented ,because he could not find one like it. not just a 2 cylinder engine.
Not sure he's going to get rich with a patent for introducing wild imbalances in two motors mounted side by side... I don't know where he got the idea that RC engines are not crank balanced for the piston reciprocation, but he's wrong. We are very careful to balance our propellers on RC planes precisely to avoid the bearing destroying vibration he created.
Gotta say massive points for using a 3 phase. I work with large multi kilowatt generators daily. It's nice to know what you are talking about from the start to finish for once lol
This is very educational and I like how you explain your development process. Might I suggest using a hover board motor as your generator. They are 36v motors and will produce 3 phase AC. It has been a while sine I took one apart, but it has a lot of permanent magnets around the circumference. You have to remove the controller board and hall sensors. An easier voltage control would be to use an off the shelf MPPT controller.
This guy is seriously good at explaining things.
At least he's not afraid of his own voice, like some people are. This is normal, only because we don't sound to ourselves the same as all other people hear us when we speak. This is because, what we hear when we speak is modified by the acoustics cause by our head and our own bodies. When other people hear us speak, our voice is not modified as much by the acoustics of our head, therefore we sound differently to others than we do ourselves.
He has the posture and the behaviour of a university professor. I really like the way he explains. I sometimes try to copy his approach and tempo for my lectures at the university. I get critcised a lot for trying to upload all as fast as i can and not letting listeners to catch up. As for the voice - there is a voice coaching technique that can be studied.
he is not that good, he called it a drone generator, yet it does not generate drones?
i have designed motor with cheap torque, but its quite heavy. - perfect for aeroplanes,but not so much drone.
@@patrickwatkins7572 "cheap torque"???
Thank you so much for your video! I am a Professor in a Polytechnic School of Engineering In Spain, we are developing a PHD thesis in this field with an hybrid system of much larger power supercapacitors and a pretty complex converter with three control loops. I just wanted you to suggest to change diodes by MOSFETS and use syncrhonous rectifying, you will increase efficiency of conversion. Your videos are terrific and the way you explain perfect 8-). I have recommended your channel to all my students. Best regards from the North of Spain and thank you again for sharing your knowledge.
True, way he explains things makes even average joe understand the topic, least on basic level of what is going on. For instance i didnt have clue about magneto hydro dynamics before, let alone even knew this field existed, but now i have project going on using this technology... Though it would be nice to ask few question from him regarding this topic and application of said tech.
Many years ago I worked on an Emergency power generator for aircraft. It used air to rotate a 3 phase brushless generator running at about 100Krpm. Very small, the rotor was no more than about ¾” OD and the length was perhaps about 2”. There were two of these in the case and air was pumped into it through a hole that was the diameter of perhaps 24AWG wire. A disc on top of the rotor with tiny little cups to catch the air was used as the method of rotor propulsion. The combination of the two generators produced 3KW of power at about 115 Volts and ran and used the air as air bearings in addition to just propulsion. Perhaps you can use this method but instead of generating power and then running a motor just cut out the middle man and run the motor directly with compressed air. I don't know how much power you need but I believe this combination of air tank and motor will be much lighter and less complicated than 2 two-stroke motors and mufflers and generator replaced by just an air tank. So even your motor becomes simpler. Just driven by air, no copper windings, but of course you will have to make the motor to run on compressed air.
What you describe is great. 100.000 rpm!!!!!!!!!!!!!!!!!, that's too much even for an aircraft turbine 8-). The idea sounds really atractive but, as you have told, the problem is compressed air. Our prototype is for a PHD Thesis (our aim is to obtain above 7 kW at 50V). We are trying to use ultra capacitors, no batteries, active rectification a DC-DC controlled converted and several control loops to the thermal motor (first carburation latter injection) in order optimize fuel consumption.
Thank you sou much for your answer!
Have a nice weekend.
Looks like he is talking about some sort of EDF before they arrived to the hobbyist market. : Generally, most EDF units will run between 35000 RPM and 50000 RPM.
www.radiocontrolinfo.com/rc-planes/edf-jets/edf-brushless-motor/
¿Dónde podría ver ese proyecto de motor hibrido? un saludo
These videos are the reason why TH-cam deserves to exist. There's a lot of content out there, but these videos spreading your engineering knowledge to the masses are incredible.
A lot of his video's go over my head, I start to wonder if I am being Turbo Encabulated. (Watch the video if you havent, Dave Rondot has a one but there are many, not all of them are well spoken but there are several that are! :)
This is very interesting. I haven't seen discussion on hybrid quadcopter power systems elsewhere, and this guy is so incredibly precise but clear in how he explains things. A remarkable channel.
Thanks! Please keep watching, we have more on the way.
If anyone is going to build the first publicly available anti gravity/time displacement/space distortion device and/or machine, its this guy. Thanks for the videos. Your comprehension and explanation of mechanics, electronics, and pretty much everything is far beyond mine.
His speaches are so well articulated, fluent and structured, it's bliss for my ears.
I've daydreamed of using a brushless RC motor as an alternator for a hybrid aircraft. Thank you for testing and greatly refining it's use, and concise explanation. As usual, well thought out and researched. Well done!
Kind of like this?
th-cam.com/video/63TqdO27IMY/w-d-xo.html&ab_channel=Electrotechnics
I once did a test flight series that had much of the same torsional resonance problems, that you described, which I discovered after about 4 hours of flight. The propeller developed a green stick fracture and the ensuing vibration caused extreme damage to the aircraft. Namely, the canopy partially detached from the cockpit and ended sitting in a vertical position on top of the left wing, which caused the stall speed to double. The aircraft stalled 3 times before I pancaked into the ground. The builder had built the 3 piston drive system with no buffering of the tortional resonance. You described the cause and effect of this extremely well. If the builder had installed the drive system with a belt/pulley arrangement as the designer called for, the propeller would have stayed intact and the aircraft would still be in one piece.
Keep up the great work.
Respectfully
Rick Mason
I'm having problem to find the words thanking you enough to share these experiments. I really do appreciate the work and effort you're committing. This is one, if not the most educational channel.
Thanks!
I owned many engines when I was an active R/C-er and Saito engines (pronounced "Sigh-tow" in Japanese parlance) are among the best in the world in my opinion. I met Mr. Saito about 20 years ago in his factory in Chiba, Tokyo when a friend and I interviewed him for a magazine article on his engines. He was very gracious and full of information, and though quite old then, was still actively engaged in designing four stroke engines for the R/C community. He was also deaf as a post having stood next to running engines studying their operation for far too long and far too often. He admitted that if you want to keep your hearing into old age you should wear earmuffs when running any R/C engine, particularly the larger ones at full throttle, as even muffled engines at close range can cause hearing damage. In the air they sound wonderful, but that's where they're designed to operate, not a few feet from your ears on a wooden test stand.
Interesting.
Stumbled on this video with no interest at all and stayed for the whole thing! Great straight forward explanations and cool to see how inventive you are.
You are SO right! LOL...typical TH-cam rabbit hole......@Frank Heuvelman
Why did i losed so lot of my lifetime before finding your channel ?!!
I'm a technician in metallic construction, I like your work and you really make me appreciate mine, thank you .
Great and welcome!
This is my new favorite youtube channel!
Mine also.
yes mine as well, just as soon as I finish watching those I have saved of paint drying
It's like Colin Furze but with more meticulous craftsmanship. Amazing videos.
He is generous with his intelligence
I am only now begining to see a couple of whole projects.
I was scratching my head, and wondering how it all relates, then boom...
Thank you for your work, and seeing your drive, is helping me get back to my tinkering
I get the distinct impression that this is very well researched, and from that, that this guy is not messing around.
He doesn’t look like the type of guy to win a bareknuckle tournament at your local pub, but if you beat him up he might just fabricate a terminator that can simultaneously beat up every competitor at the following tournament.
Sadly this is not well researched, that is why it never worked.
But the guy is very smart.
I know you've been through a traumatic (physical and emotional) experience recently, but we always loved you when you were so (geeky).
We would love to have you as a college professor explaining how the world works.
I think most of us have been through University, and understand there's more to learn past the classroom.
Thank you for everything you're doing!
It took Harley-Davidson almost 100 yrs before they balanced the crankshafts on their motorcycles. However, in the aerospace industry it wasn't long before they started balancing engines, because it was much more problematic to have an unbalanced engine in an airplane.
Someone did a bit of work making up the mounting fixture for the engines and generators.
Also, I have an Engineering Degree and 2o yrs experience in Aerospace and I'm following along with everything. Then I think does anyone else have a clue what you're talking about that doesn't have some Mechanical or Electrical Engineering background ?
Great channel I hope it inspires younger kids to put down the video games and start experimenting. We need to give the kids the resources too.
Thank you for the quality content and a lot of explanation with examples on practice. English is my third language but still, I can understand you much better than my several native teachers of physics in schools. Well done both of you!
Thank you.
Is it more a testament to this guy's skills or just that I was just playing Factorio that made me think I was about to see a drone spawning machine :)
my ADHD is suddenly cured after watching this... this channel is hands down the best source for living vicariously through someone!
Thanks. I noticed that the current with the batteries was about 12 amps and 366 watts while when the two strokes were running that going into the same load was only about 300 watts and 8 to 9 amps. Those load resistors look like they may have some inductance and this may suggest that you are dealing with more AC from you generator than perhaps you are aware. It would be good to scope the voltage across the load.
Truly, one of the best drone engineering videos ever done. What an educator!!!
Thanks!
For some reason I was expecting an audio related drone generator (think raga). Not a generator that happened to go on and power a drone... But hey, this was cool too so I watched anyway!
I was expecting science fiction... thought he was Rick Sanchez'ing up a box that made a drone every time you push the button.
Found that drone generator while not looking for it. th-cam.com/users/shorts93E77hBM-1Y
can i just say that having a complete explanation of rectifiers is really nice to have? man.... great stuff!
You can used the brushless dc motor as a starter to start the internal combustion engine and as well as a generator to charge the battery
I know. The switching from the ESC that starts the engines to the low resistance, high current input to the rectifiers is challenging. Any specific suggestions would be helpful.
We may have tackled the transfer switching issue to allow the generators to act as the starters as well.
Tech Ingredients Hi, I may be wrong but, my guess is those retrofitted mufflers you made would work great for 4 stroke, but I suspect they will get clogged with oil and back up the engine.
Using active rectification gives you an easy way to use the rectifier board as a driver for starting the engines. There are just a few extra FETs used to redirect power to bypass the output regulator and drive the BLDCs to start the engine(s) using the rectifier FETs. The catch is that if you have an optimal drive ratio to couple the engine to the BLDCs, you do not have an optimal ratio to drive the engines for starting. It is likely that you'd need a transmission to provide these two different modes.
It would be very useful for a drone to be able to restart the engines in flight. I'm assuming that a stall for a typical drone allows the batteries to supply lift for a few minutes while the engine(s) are restarted. Optimizing the restart could be kind of important. If the generator/motor set has to work through a gearing ratio that is not optimal for starting, but is optimal for power generation, then the whole mission is a fail. Based on my studies, the transmission ratios for optimal power generation are not 1:1 (They could be but I have yet to see a commercial BLDC that could support that and be weight competitive). So their would need to be two gear ratios. One for starting the engine(s), and another for power generation.
Very impressive. Very interesting.
I really enjoy how you explain all the thoughts and technical parameters about the way it works in general but also
about details, what you need to know in order to optimize the efficiency and the overall usability of such an epic generator.
And all the background about energy density differences between LIPOs, 2 stroke and 4 stroke engines and ways to compensate voltage drops
caused by (virtual) internal resistence during heavy load, you did that very good in my opinion.
Thanks!
For a gasoline quadcopter, I wonder if it would be more efficient to use the engine directly with a prop to generate some baseline thrust, with the electric motors providing the additional thrust and manovering.
Also, for teh generator, you can probably get some more efficiency, and probably also a bit less less weight by using synchronous rectification with MOSFETS instead of diodes.
for that sort of thing would work really well for a Y4 design copter
When you use multiple sources of power (hydraulic and electric, or combustion and electric), there is a higher mounting hardware cost to route the transmission of fuel and power to the different outputs. It's the intersection of the utility line puzzle with the square-cube law. The additional hardware weight would probably counteract potential efficiency gains in copter designs due to the existing complexity.
wouldn't igbts be better than mostfets? although more expensive
@SuperAWaC No, IGBTs are more robust and have higher power ratings (but a power rating of a semiconductor is the rating of how much power can be wasted inside of it before it releases the magic smoke) than MOSFETs, but not more efficient.
An IGBT has a constant voltage drop of lets say ~1V (more or less depending on current passing through), while MOSFET has a constant resistance (also depending on current passing through, or rather the temperature of the die, it has a positive thermal coeficient - so higher the temperature the higher the resistance, this is a desirable characteristic for powersharing with parallel active devices).
There is a crossover current when IGBT will be more efficient than a MOSFET (depending on types of course), but usually MOSFETs are more efficient.
For example a low Rds(on) (3mOhm) MOSFET can carry 330A of current before it's voltage drop reaches 1V, so unless you have a higher current flow a MOSFET is more efficient than a IGBT.
I think I've seen an example of that. A central IC motor for hover power, electrics for the rest.
Wonderful job so far. I love your scientific methodical approach to this project. As an Electrical Engineer, I have followed your work with ease so far. You are doing a great job of determining the parameters of your engines and generators to suit your needs nicely. Your component choices are also very good. Now, I'm going to watch your next video and see how the next phase goes.
As a fellow EE I am surprised by your assessment.
This is never going to work. There is at least one fundamental flaw.
The concept of constant voltage is doomed.
When I read the title, I thought you were designing a revolutionary new bagpipe.
With a stationary bike to power a big pump I'm on board.
Great high-level lecture. Simple, Precise, and very instructive. Very Solid Knowledge of what he is explaining. I end richer after seeing this video. Thank You
Another brilliant video! How can people not like this?!
Thank you for your excellent video.
Years ago I considered buying a lightweight generator, and had a brochure on it, which is now gone. It was called a Lightning Charger, and came in versions that put out 12 volts DC, 12 volts AC, and 120 volts AC or DC. It was powered by a 2-cycle engine, and what made it light weight was a patented permanent magnet alternator that put out about 55 amps. I communicated with the inventor about the charger's speed control.
I just looked through old emails and found one from 2004 from Coleman Powermate, which had purchased the technology, answering my question on where I could buy one. The answer was, "This unit was discontinued and was not sold to anyone else." The generator/charger disappeared from the market.
Years later I came across a document on the Internet that was about the Department of Defense appropriating the patent, which said the technology was needed for drones.
If you can find details about the alternator used for that generator/charger you may get ideas on how you might improve on your design. However, just guessing from the look of the size of your design and its output, your design may be getting more power for the size and weight than the Lightning Charger did. If so, the DOD may ...
And THIS is why we can't have nice things . . . . (the Gov appropriating inventions and shelving patents - making them disappear)
this guy should get the Noble award for DiY category
That is a bit of a reach. He hasn't invented anything new. Just adapting old ideas to his application.
Search "APU" and you'll find plenty of examples of a very old concept.
That said, he does do nice work.
@@ElementofKindness i know, but he should get the award for best utilization of free time and most resources consumed hobby :) but yes, he did well
No, he should waltz through unopposed for best educator on all things science & engineering
Been in aviation for 40 years Recips , Rotorwing and Private Jets for the last 21 a lot of moving parts there and a lot of things that could go astray with RC parts obviously this guy is a Electrical Engineer and very well done and thought out !
Thank you!
"...and AC power has to be rectified. And in order to do that we need -diodes- a FULL BRIDGE RECTIFIER"
FUUULL BRIDGE RECTIFFIIERR :)
Yeah, he sort of made it sound like having to deal with three phase, instead of single phase, is a bad thing, but is actually better for smoother output, lower vibration, etc.
@ Jay Dee A full bridge rectifier is just diodes arranged in a manner as to take advantage of the high and low peaks of each phase. The reason he said a 3 phase motor would need 6 diodes is because it's arranged in a "Full Bridge" configuration. You could actually get away with three diodes per motor/generator however you would be wasting 50% of the power.
Yeah. I guess to store the charge. But isnt the output from an ESC basically AC? But even then, there's fluctuation in all motors.
Lol. So you have to generate it, rectify it, store it, and convert it back again. Right?
Full bridge rectifiers are only about the size of a quarter though.
This is THE most informative, best explained video on UAV hybrid power I've seen.
Thanks to all who produced it, and made it's complexity easy to digest: you have one very happy new subscriber!
Two stroke engines run with specific exhaust pipe back pressure cutting or changing the exhaust pipe is like changing the cam timing on a four stroke it might work on a small engine but should not be done !!!
what the hell did i just watch. In one video, you've become my fav maker on YT. I have your whole channel to binge through!!!!!
diggit
kudos for taking the time to not only complete all these projects but to also make the videos as well
Thanks for some great introductory explanations using your uniquely engineered power supply. The next step would be to investigate the efficiency of the system. You need to put the fuel tank on a non-vibrating surface with a scale to calculate the fuel consumption. From that it's a simple bit of math to get your power efficiency. BSFC (brake specific fuel consumption) would be useful in finding the optimal load for any given rotational speed, load dependant.
For the muffler system, I would strongly suggest optimal design software like Virtual 4-stroke to get more specific parameters to run your engine system. It'll help optimize exhaust and intake design by specifying targets like BSFC or power.
Could you post the weight of the entire setup and also include the cooling fan load when computing efficiency? From your previous video's I figured you would have designed a cooling system that was mechanical to mechanical (direct drive fans). Future work perhaps? All in all this looks like a fun project and one that could help with understanding thermal loads. Your alternators would be getting pretty hot if run at a constant duty cycle. Thermal camera footage perhaps?
Thanks again for showing off your work with patient explanation!
You are a serious genius. I enjoy all of your videos. Your explanations and professional research procedures are excellent.
Thanks!
Many years ago I worked on an Emergency power generator for aircraft. It used air to rotate a 3 phase brushless generator running at about 100Krpm. Very small, the rotor was no more than about ¾” OD and the length was perhaps about 2”. There were two of these in the case and air was pumped into it through a hole that was the diameter of perhaps 24AWG wire. A disc attached to the shaft just above the rotor with tiny little cups to catch the air was used as the method of rotor propulsion. . The combination of the two generators produced 3KW of power at about 115 Volts and also used the air as air bearings in addition to just propulsion. Perhaps you can use this method but instead of generating power and then running a motor just cut out the middle man and run the motor directly with compressed air. I don't know how much power you need but I believe this combination of air tank and motor will be much lighter and less complicated than 2 two-stroke motors and mufflers and generator replaced by just an air tank. So even your motor becomes simpler. Just driven by air, no copper windings, but of course you will have to make a motor to run on compressed air. Since you also want to control the voltage, you may also need a PID control for an air valve which is almost nothing. I also designed a controller with a 1KHz bandwidth for a hydraulic valve for aircraft control surfaces. Just 1 Amp for the control valve. Perhaps you can find a simpler way to control the air flow. What is your response requirement?
As an electrician; I Love the way, you explain things, mostly understood by an electrophyte...I know what you are explaining.. Right now, I'm playing around with Maxwell Capacitors...Dont try it folks!
Thanks for the video. Can't wait to see the drone flying!
Thanks! Check it out th-cam.com/video/zeQasZlCiJ4/w-d-xo.html
Tech Ingredients this maybe stupid..but why not use a rotary engine? Or a boxer two cylinder?
Did you mean a winkle engine, as in Mazda? Or for that matter, why not a reverse polarity magnetic rotary engine lol
A wink or a nod, it's all the same to a blind horse
Great video! I thought up the same idea of using a generator to power a drone. Because I was thinking of a way to use engines to make a drone. I figured it would be impossible to use engines to directly drive the propellers, because the speed of the engines could never be controlled fast enough. It's nice to see someone actually doing it. Another benefit of using gas, other than more kiting capacity and longer flight time, is being able to just refuel to keep flying. Other wise you would need to wait for your batteries to recharge or have multiple spares. Even with the cost of building that system, it's probably still cheaper to fly all day than it would be to have enough spare charged batteries to fly all day. That the reason I love my nitro car, I can drive that all day. If it were electric I'd get 10 minutes of play and then would have to wait a couple hours for my batteries to charge.
It doesn't take a couple hours to charge a lithium battery pack today. A 5000mah 3S lipo battery pack will run my brushless electric 1/10 scale, dirt oval, r/c car for about an hour, and it takes about 45 minutes to charge the pack. I can run all day with only 2 battery packs. I have nitro 1/8 scale cars also, but brushless electrics have come a LONG way today.
It's so crazy how you are doing all the experiments I have needed for my projects. Have you considered using VESCs (vedder electronic speed controller) in replacement of the rectifier circuit? More expensive solution, but you can start the motors with them (useful in failsafe situations), and may get better efficiency than a rectification circuit. You can also get accurate RPM readings from the VESCs allowing you to more accurately control the throttle. You could even write an algorithm that cuts back on the power generation voltage through PWM inside the motor controllers when it detects the generator is bogging down, allowing less voltage sag under heavy generator load. The two engines could also be decoupled mechanically if you used an encoder with each VESC and set them to run at the exact same RPM with the same encoder offset. (it has the processing capability to do this accurately enough I would say to be just as good as a mechanical linkage) This would allow for the same balance that you currently have, but less mechanical hardware, and more importantly redundancy in the design. Two fuel tanks, two throttles, two everything. Redundancy is always nice when you have expensive equipment flying in the air lol. A boxer engine setup may further decrease vibration and may eliminate the need for counterweights on the flywheel.
Mechanical connection makes them basically one motor. That's better.
Check out my TH-cam channel, I had the idea to use a VESC as an active rectifier after I built my skateboard. I ran an experiment yesterday and it was promising.
It was good to see your evolution from the 4 stoke to the two stroke engine and all the explanations leading up to .it’s interesting problem solving stuff .thanks for the vid
Holy cow.. How BIG is this Drone gonna be?? Will it cross the English channel on 1 tank of gas?
Love your videos and the technical accuracy (correctness) that you demonstrate.
I am working on a gas powered quad, and found the same thing you did regarding torque pulsations.
I moved from a 4 stroke engine to a 2 stroke. Also added a flywheel to minimize amplitude of pulsations through my transmission.
The 2 stroke runs well at higher RPM's, so with greater gear reduction, this also enabled a lower torque (at the engine) for a given amount
of power. Still had some problems during accel up to operating speed of resonance on the soft motor mounts, but not enough to ruin anything.
Did have to go to a carb with diaphragm pump, not float, due to the high level of vibration.
Thanks and interesting. Our vibration is very low, but in an airplane
installation, the vibration should be at least as high and probably
higher than yours.
I think some Maxwell boost Caps or supercapacitors will greatly improve the setup and also allow you to reduce the size of your battery packs and still maintain of a set time limit if you have mechanical failure to get the Drone under the ground safely.
A fine tuning of the energy storage system, by topping off the lithium ion batteries with super capacitors might be useful. The bulk of the energy back up will need to remain in the batteries because an emergency landing could take as long as a couple of minuets and the energy density of the batteries will be more important then the power density for this kind of time period.
Tech Ingredients the reason why I thought of it is because people are actually replacing car batteries and testing with supercapacitors and having better luck than a regular battery and they're fairly light. They have a super low internal resistance they charge almost instantly. Now the number that you would need to get to the voltage that you want may make it unfeasible but as the technology gets better and better eventually batteries will be replaced.
I'm aware of that application in starting automobiles and it makes sense. The actual number of joules used to start a car is really quite low and far lower than the energy storage capacity of lead acid batteries. It is the peak power requirement that has determined the sizing of automotive batteries and so with a super capacitor to supply the peak power a much smaller and lighter battery can be used. Batteries are improving as well. Magnesium ion batteries may begin to make an appearance with double the energy density of lithium ions and of course, fuel cells are getting closer and closer to realistic availability. We'll see.
I have watched a few of your videos, very informative, you must be a professor, but definitely experiments for people with brains or who use them, I appreciate it thank you for uploading, I'm in the field on the electrical side so I understand most of the terms and explanations.
Please complete this project. This one brought me to the channel and you start a LOT of project, but they just stop and aren't completed! Please finish, theyre so interesting!
I have watched some of your videos. You are the best teacher I have seen in my life. Not too much, not too little, the in-between reached. Teachers should be like you, then we would have paradise on our flat earth.
Thank you!
12:21 but the shaping of an exhaust is a key to the power generated by 2strokes engines, isn't it
Didn't he say 4 stroke
@@MrBobWareham @ 10:30 he talks about locking the engines 180° out of phase, and having a continous power stroke, so with that setup they would be 2 stroke engines. Plus, the sound. They're 2 smokes.
Yes, the chamber volume, exit coss-sectional area, etc, do significantly affect the engines power delivery. He didn't mention tuning the muffler, but knowing the detail involved in all of these videos i'm guessing he did the maths.
Wow a TH-camr with actual knowledge of what he is talking about!!!! quite enjoyable
Whats the watts per Kg and watts per Volume (Power density) fuel conversion efficiency
RC plane rotary engines are out of the question?
They’re high revving and smooth running although not too fuel efficient.
My thoughts exactly . More power @ lesser weight.
When reading the title, I first thought you were generating Drones, but didn't even really question it on this channel.
Interesting. Every small engine I've worked on did have a counterweight on the crankshaft though given how close to the center of the crank they are they probably don't completely offset the static Wright of the piston and conrod
Do R/C! Exactly... I think the unbalanced counterweight is doing nothing but wearing engine bearings/bushings prematurely.
Aradialenginemighthelp, butheyareexpencive.
Another great project with solid engineering and again I can't help myself from making some friendly suggestions:
1) I think you're paying an efficiency penalty by pursuing the anti-vibration goal. 2 small motors will be less weight and fuel efficient than one large on producing the same power. Perhaps there are other ways to deal with the vibrations such as isolating the motor/generator from the flight controller?
2) I saw another hybrid drone project that used a propeller on the internal combustion engine to generate most of the lift for the drone and then use a lesser amount of transformed electrical power for stability and control motors. You kind of already need a big propeller to deal with expected cooling requirements of the I.C. engine. Saves the conversion losses going from mechanical to electrical
3) I don't think you need your capacitor bank if you already have to have the battery packs. Think of the batteries as "super" capacitors.
Very useful. Request you to kindly show the detailed video on how to make the generator assembly (complete), including the 2 motors placement at 180 degrees with weight offset balancing. I am working on the hybrid power unit,. your consideration would be a great help for me.Thanks with regards
Yes. Agreed
THAT IS A HORRIBLE REQUEST. DID HE SAY ANYTHING ABOUT OPEN SOURCE? WHY WOULD HE SHARE THIS INFO? WOULD YOU SHARE ALL YOUR INFO WITH HIM? WOULD YOU PAY FOR IT? WOULD YOU PAY AIR FARE AND LODGING TO GO WORK WITH HIM FOR FREE? NO? OK THEN, BUZZ OFF MAN.
I mean, if there is a problem with what darpan asked for, all he has to say is "no I dont wish to share this information" or they could work something out in a more private manner. So there for your two comments in all caps were are still are unnecessary. Have yourself a good day :)
Nimbos0 YOU'RE CORRECT AND I DELETED THE SECOND COMMENT. I WON'T MAKE AN EXCUSE WHY IT WAS POSTED TWICE. OK, LATER ON.
Mc cc: I am not going to comment on the intricacies involving intellectual property. What I am going to say is that you are absolutely not entitled to make either a moral judgment on a request for more information, nor are you entitled to tell tech ingredient what he will or will not divulge about his ideas.
Darpan: the concept seems relatively straight forward to me. It's basically two engines mounted next to each other in the same plate; then synchronized with an ordinary timing belt and sharing a control solenoid. I actually see a few similarities to Edison's original generating plant; where they had to synchronize the two generators, so the faster one wasn't driving the slower one.
You have an incredible presentation skill. I know many people who are excellent engineers or great presenters, but very few people who are both. I wonder how much power the commercial drones can generate - after all it's only around 300W or less than half a horsepower - probably not nearly enough to lift the motor with the fuel alone, not to mention the entire drone. This video shows really well how hard it is to build an efficient system like this, not to mention making it a working product, which is way harder than building a prototype.
Thanks!
expansion chamber exhaust for 2 strokes will nearly double the power.
It is my understanding that a tuned exhaust on a two stroke will increase the fuel efficiency and power by approximately 12-15%. We are using the DLE 20 single cylinder engines as well as the DLE 222 4 cylinder engines. If you have better information or a link to a source for a tuned exhaust that is compatible with these engines, please send us a link and we'll pursue it.
Increasing the power output will also increase the operating temperature and might lead to overheating, seizure, etc...
It was a privilege to listen to the information you provided. Thank you very much
Love the project that engine looks very nice but I would have used a small mechanical fan driven from the main motor shaft to save electric with the fan thanks for the video.
I love your content. I can’t get enough of your videos. I am envious of your shop. But on a side note you should be in every high school science class across the nation.
Thanks! Maybe we will be someday.
If the concern prompting the hybrid solution is the higher energy density of gasoline versus lithium polymer batteries... why not just build a pure gas-powered multirotor? This way you would not have the losses and weight of the generator/rectifier system.
However, to get around the insufficient response times of using individual gas engines in place of your electric motors... use a single gas engine running at an efficient RPM... and run collective (non-cyclic) pitch rotors. Your flight controller could manage the collective pitch servos and could provide the necessary responsiveness.
For example:
www.curtisyoungblood.com/legacy-product-support-curtis-youngblood/attachment/stingray-500/
Well, you're right, but one purpose for a multirotor (and the reason of it's reliability) is to defeat as much mechanical links and failures which could appear trough them. If you want something with variable pitch props, and one motor, why not build a helicopter (proven design)?
Because cyclic pitch is another class of difficult compared to non-cyclic pitch. The latter isn't that hard.
Gas powered multirotor? Not if the power to an individual multirotor motor has to be adjusted 400 times per second minimum in order for it to stay level/hover
Multirotors vary the rpm of the individual rotors to provide directional (yaw) control. A direct-drive gas system is not responsive enough. Electric drive is the only way to go here. Less complex and much better control.
I watched a 2 stroke manned drone. He changed over to electrics.
Hybrid is the long range solution though.
He's packed 27m39s full of pertinent facts. Even his extraneous comments are informative.
Thank you.
So what's the math look like on the energy density of the entire unit?
E = mc^2 ?
You’ve given me an idea ... thanks for such a detailed and analytical video. Must be huge fun.
3:37 anxiety attack incoming
My brain is numb with information. Thank you for this video. I've been doing research on this type of setup for several applications I'm currently designing.
Only 250w generated? It'll probably take more than that just to deal with the huge amount of extra weight.
You are so smart. You should explain that to him.
The resistors he used draw 250 watts at this set voltage. That doesn't mean the generator isn't able to supply more when you increase the power draw.
This is simply stunning engineering, I know all about motors but not electronics, even though I do electronic repairs in vehicles. I knew about the timing belt solution and the issues with twin cylinder two strokes being in phase, but the whole assembly is genius.
You do so well at teaching, kudos to you Sir.
I hate those Saito four strokes, give me a two stroke any day. The idiots at the flying field were real proud of their Saitos, but I suspect I was getting more thrust out of my 10cc Chinese two strokes than they got from their overpriced four strokes.
Haven't been flying for a while, I need a new location for flying since something is screwing with my AFHSS system at the approved airfield. I didn't think it was possible to interfere with such systems, however, the nature of my last lost airframe made me suspect someone has such a system.
Hitec makes a great radio, the Aurora is affordable and under normal circumstance is flawless.
I look forward to you flying this new system, and learning everything you have to show.
Thanks again...
Thanks!
This video kept popping up in my feed... and every time I see it, the image of a machine that just generates and releases a lot of drone just come up in my mind... and then in snapped back... ah, it's a electrical generator, not generator of drones... :P
I came here looking for the same thing, some crazy drone generator =). Still a very interesting video.
Absolutely AMAZING video. I hope this turns into a documentary someday, and ultimately I hope your character in the blockbuster movie is played by YOU.
2 engines... in opposite directions.
i see u had the same idea later on ^^
Yah! I was thinking the same thing.. like half of a Volkswagen boxer engine - the horizontally opposed piston setup should allow lighter flywheels. (I saw the comment that he thought of the boxer cylinder arrangement later but I haven't got to that part yet - just found this channel and it's great!).
or 1 boxer engine :)
It might make a reciprocating linear vibration like the hydraulic pecan harvesters.
Love the content as always, thanks for going in on the broken part.. you were moving in with the camera just as I thought "hmm, I wish I could get a closeup on the breaking line.." lol
I can tell that he's an animal in bed......
Enjoyed your show. Hope to see more videos.
You can filter out ripple by using a so-called „capacitance multiplier“ circuit. EEVblog has a video about them. They use a small capacitor, a couple resistors and a transistor. Since the transistor multiplies the effect of the filter capacitor, you can considerably reduce the size of the filter capacitor, which saves a lot of weight and space.
This is so cool. I've watched most of your other videos already and it's taken me a while to get to this one. Very impressive work with the drone generator and I appreciate the in depth explanation of how you balanced everything.
The coupler that you broke could be replaced with a lovejoy coupler. Those, if you're not already aware, have a rubber dampening piece that separates the two metal halves of the coupler. They use them on cam driven fuel pumps on high horsepower motorsports applications because it removes the shock loading of the metal parts. I don't think that's the correct scientific term, it may be, but that's what causes it to break.
Thank you for making these videos.
Thanks!
That is the coupler that we eventually went with.
Finally, a scholarly approach to power generation using small engines! Great info!
Thanks!
you are dangerously close to inventing the twin opposed engine. very nice work thanks for the video.
A hybrid system of this type is what I always dreamed of for my ultralight or airplane. That way, in the event of any gas motor failure, you have an electrical reserve to reach an airport. If the battery pack were large enough, it could also have incredible hybrid like fuel savings (which is very relevant to flight costs especially for a recreational pilot). This arrangement might also provide the incredible ability for some quiet soaring time (since stopping a gas only motor in flight for this purpose would usually be unsafe) since a restart would be assured.
You seem like someone who would enjoy building/flying an ultralight as a project... I think a hybrid ultralight would be a thrilling addition to your inventions! (I'd be happy to help test fly it.) Thanks for all you do to spark learning, from a kids science teacher. :-)
Your videos, communication / teaching are legend .
Strength! Never falter! Smiles! What better fun to watch! Keep pushing forward!
I very much enjoyed this video and your teaching style is great. What you are building is a serial hybrid. As others have commented, the complexity and weight, and most importantly the conversion losses will overshadow the gains. Perhaps you should try a parallel hybrid. Use the engines to generate 85 percent of the upward thrust needed to hover the craft. Let the four electric motors make up the rest of the lift and provide control. You could use an inline pancake generator to supplement battery power, but you would be better off having no generator at all and simply sizing the fuel tank and the battery to have similar run times. I have been thinking about trying this for a long time. Counter rotation is the key.
There are arguments for and against both approaches.
It is incorrect to say that the loses will overshadow the gains. For short flight times, the up front weight of the generator will dominate, but for short flights, the justification of either hybrid approach is questionable. As flight duration increases, the use of the far higher energy density of the fuel overwhelms the added mechanical weight. A modular, add on generator, is easier to incorporate onto existing multi rotors and is easier to isolate regarding noise and vibration, but it provides less efficiency than a parallel hybrid due to conversion losses. The purpose of the multi rotor will determine what is the better approach.
this is an exceptional video, thank you so much for providing so incredibly much information in this short video, absolutely phantastic!!!
That stand of trees behind you is very beautiful.
At the beginning of the video you mention the power density of batteries. You are correct when you mention the power density of batteries being much lower then gas. However, after building this whole system your power density of your gas system is much lower then originally estimated due to need for a engine and a generator. You also have a significant loss factor of your gas engine (generally around 30% eff) and a loss factor for your electronic components (probably around >95% eff). I'm sceptical if you can overcome the extra weight and losses and still have a higher energy per unit weight and volume when compared to the batteries. Did you calculate an expected expected energy density of your final system?
That's an important point, but the analysis has to be different. Unlike the batteries, the generator module is a fixed weight independent of the fuel quantity available. With little available fuel the energy ratio is terrible. As the fuel supply increases the ratio continues to improve and asymptotically approaches that of the fuel itself. The generator is a bad alternative if short flights are the goal.
@@TechIngredients I agree with your analysis. However, if you fix your system size and increase your available fuel the system will also increase in weight but not necessarily increase it's power output by the same amount. If I understand your goal correctly you want to produce a drone with a longer flight time then one of batteries. You are therefore need a specific power output to lift your system as well as the drone. If you increase your fuel supply to improve your ratio, as you mentioned, the power generation system will also have to increase in size to counter the increased weight. Thus there will be an optimal fuel supply amount and power generation size. This optimal may even lie much larger then you would think.
Thank you for the response! I find your videos very thought provoking.
That's correct, but also applies to batteries when you factor in all of the lift system such as the mechanical strength of the arms, the gauge of the wiring, the motors etc. The engineering is complex and nothing is simply linear.
While I am a great admirer of your positive enthusiasm and your eloquent way of explaining such elaborate details of your generator.
I don't know if you have considered that a drone requires about 100 watts per every pound, that is including the weight of the drone. If your generator weighs 50 lbs this means obviously you will need 5 kilowatts just to lift the generator plus you will need that much more power to lift the drone and I doubt that your generator will ever produce anywhere near 10 KW at 50 Lbs.
If I were you I would be considering the design of a drone that would fly on gas, this way you will take advantage of 100% of it's power and avoid the vast losses of generating electricity to run electric motors... it is not impossible, I know that throttle acceleration is not fast acting enough to control the needed variations on each individual propeller but it can be done with a system of continuously variable transmission on each propeller being powered by one single engine.
Hands down best all around info on all objects
You are totally right with the pulsing. This is true for any electrochemical process, due to the diffusion limited currents that are caused by the depletion of Ions in the Electrode region and the resulting low ion concentration surface layer(Nernst-Planck Equation (the defusion Part)). You just you just have to make sure that The overall surface area is large enough so that your net current is depleting little enough volume to be replenished during the relaxation time between the pulses.
This was all ridiculously over my head. I did, however, enjoy the video due to the in-depth explanation of every step.
For drone use, it is quite possible to use an ESC to start the engine. Some ESC units may have trouble with the higher RPM when the unit is set to slower than running speed, and thus overheat trying to apply brake. Contact your ESC manufactures for ones that can be used for starting and electrically disconnected when returned to idle. You do not want a reversible unit or one with a brake function. This may allow use in an enclosed airframe where access for starting may be limited.
wow. thank you for the break down! you're an incredible teacher... where have you been all my life!
You're welcome!
balancing those two engines was freaking genius. i hope you patent that if possible.
Patent a 2 cylinder engine?
Zach A did you actualy watch the video or read all of my comment? Patent the balanced special 2 cylinder engine he invented ,because he could not find one like it. not just a 2 cylinder engine.
Not sure he's going to get rich with a patent for introducing wild imbalances in two motors mounted side by side... I don't know where he got the idea that RC engines are not crank balanced for the piston reciprocation, but he's wrong. We are very careful to balance our propellers on RC planes precisely to avoid the bearing destroying vibration he created.
Gotta say massive points for using a 3 phase. I work with large multi kilowatt generators daily. It's nice to know what you are talking about from the start to finish for once lol
Thanks!
Interesting. Hybrid systems tend to be heavy and big. You incorporated a bunch of electrical stuff I encounter every day.
This is very educational and I like how you explain your development process. Might I suggest using a hover board motor as your generator. They are 36v motors and will produce 3 phase AC. It has been a while sine I took one apart, but it has a lot of permanent magnets around the circumference. You have to remove the controller board and hall sensors. An easier voltage control would be to use an off the shelf MPPT controller.
Any brushless D.C. motor will work as a 3-phase A.C. generator.
New to this channel, been watching it all week. Good stuff I like learning.