OTV 7

[@zealeigh]

Thank you for documenting, sharing and analyzing your work so openly. Very interesting stuff! Looking forward to updates.

[@ProlificInvention]

Awesome, this is amazing to see. Hey, love all your videos-big thumbs up from a fellow tinkerer in Michigan. So I just wanted to put it out there for future video ideas that an AGNI/Lynch motor would literally be perfect for an electric motor repower project on this device or any other smaller vehicle project: The AGNI or Lynch motor is a unique axial gap permanent magnet brushed DC electric motor. The motor has a pancake-like shape and was invented by Cedric Lynch in 1979. The Lynch motor is built from ferrite blocks sandwiched between strips of metal, instead of conventional copper coil windings, and is held together purely by magnets. The motor is available in several sizes (6.6 lb) to (24 lb) weight and provides a power of 1.5 kilowatts (2.0 hp) to 11 kilowatts (15 hp) within an efficiency range of 80% to 90%. Any voltage battery up to 80 volts can be directly connected with a rheostat or a variety of controllers will work such as cheap PWM or golf cart controllers of many power levels. I've even ran mine (AGNI 15kw capable) off a 3Kw brushed motor controller for an ebike. What's amazing is the torque produced: I once hooked a single 18650 battery directly and the shaft spun about 90 RPM and had an incredible torque for such low voltage and motor speed. A 9v battery spun it about 300rpm and you could not hold the shaft from spinning with your hand, 48 volts is about 2,500 rpm and it will rip a back tire right off an electric bike. A very interesting motor so I thought I'd throw it out there, thanks again for excellent and interesting content.

[@WeAreTheTrueMedia]

I could go on forever praising your ingenuity on many points but the thing that thrills me the most so far is that you're going ICE rather than electric in a world that says you're mad 👌🏼

[@idjtoal]

But it's the world that's gone mad, currently. So much of the electric push is political, and control-oriented. They'll be a more reasonable fit when battery densities are a lot higher, and electricity generation is more efficient, and less agenda-driven.

[@adpsimpson]

Thanks for the update, I was wondering how far you'd got with this. I commented the last time about the reliability of the gearbox, which is a single point of failure. However in this video I'd also be a bit concerned about fatigue of the welds between the radial arms and central column. Aluminium has a finite fatigue life, and significant vibration will cause welds to fail quite rapidly. Good luck, and keep at it!

[@DktheWelder]

Looks really awesome! With four of those motors you would have plenty of power!

[@jetboard]

Funny to see you here. How's the jetboard?

[@DktheWelder]

@@jetboard it would be going great if I could afford one of those motors! I’m working on another project at the moment. I always watch this guy he is super clever

[@mihavuk]

I knew you won't stop until you fly with this. 👍 If you could get 4 old Sachs Wankel / Rotary engines (the ones without gearbox), it might work. Amount of vibrations is very minimal for obvious reasons, they are air cooled which is actually an advantage for your application and almost no tradeoff considering how they are built and how they work. Efficiency is bad, as it is bad with all 2 stroke motors, so no tradeoff there. But they might be hard to get and they might be as expensive after full rebuild than those Polinis. They are German product, very hard and expensive for people in USA to deal with so that might be your advantage. 🤔😉 In each case, be careful and I'm looking forward to see your progress. 👍👌

[@poobertop]

Now that would be cool!

[@mattiasfagerlund]

Could the control slats extend beyond a rectangular frame, allowing you the best of both worlds? The slats would have to be removable, otherwise it would be as hard to store, but perhaps that's doable... Cool project!

[@ttmallard]

Sand is OK if extra fine, wet & packed, there's an official way that better & expensive, with some bends drawing needed, good 3-roller benders do most hard bends with a couple tries to get it down. As a magnet motor designer, imagine no batteries, no fuels, flux fades-10%/1000yrs, no shop atm, will keep tabs, great line of thinking. Kudos 🍺

[@woodturner1954]

Very smart designer/builder using the storage container for safety.

[@dwk5234]

Excellent, creative visualization and fabrication combined with a scientific, thoughtful approach. Thank you !

[@tonysargent1699]

AMAZING!!! I am filled tingles to see the next part. Thankyou for sharing, its most enjoyable.

[@RasmusSE]

Wow - you are unstoppable! Amazing work, really entertaining to watch.

[@kushnpush6480]

You should coat the motors outer surface and the aluminum bars with Dynamat or some other sound deadening material to cut down on the vibration... hopefully the lack of vibration will out weigh the extra weight it caused. Just a thought.. nice job keep it up brother

[@nathanchalecki4842]

I absolutely love this. Many people have ideas but not many back their ideas with action and money! Two points, sorry if mentioned elsewhere. Firstly, there are four motors and presumably four pinions driving two ring gears (I haven't seen your other vids or all of this one sorry). The one ring gear per blade seems like a real weakness-if something loses a tooth and destroys thay one gear then four motors won't help you. Secondly, although this is an excellent configuration, you appear to have all of the skills and money required to build a more normal configuration helicopter (like the mosquito!) which (to my uneducated mind) removes a huge number of variables and potential failure points

[@nonaurbizniz7440]

You need rubber vibration isolation gaskets between that engine and the frame. Also another engine directly opposite will allow for some measure of harmonic balancing and of course double your available power.

[@macsterguy]

One of my very favorite guys on YT!

[@markspc1]

Outstanding project. I am glad to see innovation in aircraft design.

[@LQhristian]

Great work!! I hope hope you consider adding outside braces to the bottom of the frame to add rigidity!

[@BShandyman]

Triple redundancy?! This guy knows he’s unlucky haha Why not run two motors simultaneously to overcome the additional 12lbs or would that not work? I love the concept! Keep it up 👍

[@gth042]

Overrunning/sprague clutches will be important in any motor setup (dropping out below flight rpm=bad). Turboshaft is even more so (they won't stay lit for long). Before you ditch the 2-stroke engine, is it possible to try a steel lamininate disc coupling and rule out torsional oscillation from the rubber? On power package weight, is it possible to use the aluminum frame as the radiator? Partitioned off (e.g. with stiffeners & gussets), the available surface area should be close to or larger than that radiatior. yeah, fluid weight would go up, but it'd be elegant. :) Drop hollow plastic balls into the frame tubes, and it might even help dampen. Something for much later in the process... Thank you for mustering the courage and time to produce these videos.

[@PhG1961]

Waw ! Very impressive ! Can't wait so see what's next !

[@jetboard]

Your projects are amazing, and I wished I was your neighbor :-)

[@Redneckmfg]

I agree !! he is simply a genius...

[@rayeaglenz]

Yes thank you for filming, editing, creating these very interesting videos of your clever creative projects, looking forward to your next video 👍😊

[@pimplequeen2]

I think the drive rubbers will allow that end of the shaft to flail... I would only take a small move to throw it into an eccentric off-center orbit. A Thomas disk coupling "might" solve any flail issues if they occur. I have a similar design drive (using Thomas disc couplers X2 / Carbon fiber shaft) on a three axis ultralight, the drive is not yet built but even with the axial rigidity of disc couplers and low drive shaft mass, I am still quite afraid of flail. (Max 8000rpm) With your reduction (maybe Max 2800rpm) you might be ok... but I have my doubts especially as the rubbers age and soften. I will be watching with interest as I am close (ish) to fitting my the motor and building the drive and its an aria I am very nervous about :)

[@sharedinventions]

I have seen connecting shafts with rubber a disk, where shafts are connected with bolts to the disk alternating from both sides. That might help to reduce the vibration of the motor transferred to the gearbox.

[@sharedinventions]

@@SystemsPlanet Not exactly. I say, that the disk should be made out of rubber. He has metal disks with rubber joints. The bolts there still projects the vibration. (But I'm not an expert in the topic.)

[@zevi]

Fascinating project! Cant wait to follow this progress!

[@poobertop]

I'm glad to hear you mention turbo prop, that would be really interesting. Quite expensive though, no doubt. I love your videos, thanks for sharing.

[@justharryjohnson7250]

How are a mad man. But a very clever man too. I look forward to the progress you make on this machine 👍🏻

[@bobbishop9339]

Looking at you design I was thinking move the radiator to the bottom, you will get enough air moving through it and move some weight down. Also Lotus used rubber dognuts on the Elan , and I have seen several cars to day that also use them. Of course you don't get to chose the hardness.

[@roberthaines4221]

Please forgive me if you have explained this elsewhere, but I am curious why you chose to not have the inner driveshaft extend down to the lower frame, and into another bearing -- if for no other reason to reduce any risk of lash under load.

[@MrZendor]

Nice progress. This is a really interesting project.

[@d4ro]

if you add a bigger upper fuselage part like a rocket that creates drag it could potentially be easier to avoid overtipping, besides slightly larger control surfaces

[@vertigo2893]

Can you (or the flight controller) control the power on these 2 stroke motors accurately and fast enough to have any hope of hovering/soft landing?

[@captainTubes]

Yes. The co-ax config he has arrived at has a certain level of intrinsic stability so he will have full control decending downwards through a powerful ground effect. The ground effect will be large do to the concentration of thrust near the underside of the aircraft and respectfully large diameter of the propellers. If the aircraft is not using it's peak power just to sustain hover just out of ground effect (weak/inefficient etc. I hardly imagine this could be the case...), but allocated ample power to maintain torque when throttled just below hover, then it's thrust regimine will allow a similar experience to a car parking in a driveway, or to wit a Eurocopter landing near a red carpet.

[@vertigo2893]

@@captainTubes Coaxial doesnt help in this regard at all. If anything, its detrimental as those are some really big propellers with a lot of inertia to speed up/slow down. You need tons of torque to control that, something ICEs, and particularly 2 strokes arent great at. I dont think Ive ever seen a combustion engine powered VTOL that doesnt rely on variable pitch (or thrust angles) to control vertical speed. There is a reason electric motors enabled the current vtol revolution. Anyway, I would power this with electric motors, and to overcome the endurance limit, maybe a combustion engine + generator or a single combustion engine that provides a fixed power output and electical motors to provide control.

[@AtimatikArmy]

Polini, nice choice, very high power to weight ratio, made in Italy... expensive!

[@AtimatikArmy]

The weight spec is most likely with the unit "dry" (no fluids added).

[@KymHammond]

Intriguing. Would light helicopter rubber belt drives be a better solution? The motor would need to be mounted sideways to the central gearbox coupling but as with helicopters, the light belts have the added advantage of instantly absorbing and isolating engine vibrations. Eventually, the weld’s will need to be at a standard suitable for flight but as with all experimental ultralight craft all of the fun is at the experimental stage. Looking forward to your next instalment.

[@JoeZip25]

Bush Hog brush mowers had it all along .

[@Alexander_Sannikov]

i actually like the 2-stroke sound. idk why you find it annoying. maybe get a better muffler if it's a big deal for you?

[@martin_mue]

Amazing work! What about a hybrid solution for powering it. I'm thinking about redundant Honda inverter generators plus a small buffer battery/capacitor bank. The Honda EU20i is 2KW at 21 kg. And it delivers that power at 52dB(a) 🙂

[@DerKrawallkeks]

I think the generator idea is not good unfortunately:) this sinle engine has 33hp, which is a bit more than 24kW. Four of those will maybe need to produce 40-80kW to fly. A 2 kW generator is irrelevant in comparison, and at 20kg it's way too heavy. A single one of these engines weights the same, but makes 12 times more power. :) Electric hybrid would be interesting, if two gas engines are enough for flying, and the electric motors are just there to take over for a short emergency landing in case a gas engine fails.

[@ghostisblack]

i dont understand a lick of it, but always interesting stuff.

[@nightdogggg]

I have come to terms with the fact that on earth we have propellers, a crude and dangerous form of propulsion. I wish someone would explain why we waste time on light aircraft that use propellers. That guy that is working with ion thrust, now there is a worthy project. This is hobby stuff. You need a car that can fly, but not in a human blender. I would say your genius is being wasted. But , I just cannot wait to see your next vid. Thanks for the hard work.

[@TheTrumanZoo]

Wish i had someone like you

[@Wolfenion]

Go electric, or maybe a turbine electrical hybrid setup to increase you flight time? Well done and thank you loads for sharing this amazing project 🤙

[@drewgossage8842]

Another informative upload, thank you very much👍👍

[@stepyhenjkm]

The dummy propeller might have been fluttering, that would cause a huge amount of vibration.

[@Chris-bg8mk]

I’m hoping you go back to electric. Safer, more reliable, and batteries keep getting better. Live long and prosper!

[@onjofilms]

Really interesting stuff. Looks like a lot of fun. You must have a supportive wife which helps. First thing mine would ask is "how is it going to make money?". Nice TIG machine you have. I can't believe it's available all around the world, except the US.

[@caturlifelive]

Imagine, if he lives in 1910 and someone walking in the forest sees him flying his machine, then suddenly ww1 starts

[@DanFrederiksen2]

I get the aesthetics of the balance and unity of the propulsion setup but it's very exposed and inelegant to have to get on top of it. In the airflow. Two rotors could balance eachothers on each of two tilt wings instead giving natural room for passanger between the airflows and with tilting wings the craft has an efficient high speed winged mode where a hover craft is fairly doomed to hover in place. I would encourage getting excited about the less compromised aesthetics of two tilts wings which would at the same time be the control surfaces. A very clean design.

[@bigcheese781]

Don't be surprised by specifications, performance numbers and data being incorrect by an Italian manufacturer, especially one with connections into the automotive industry. Believe me, they are always a joke. Italins say 165kg, real physics say 198 kg. Italians say 38 Hp, calibrated DIN measurement states 24Hp. Never ends, never surprises.

[@marc_frank]

how about some liquid piston rotary engines don't know about price, but they seem really cool

[@Ben-Dixey]

Great stuff, love your projects, this one is going to be just as interesting. 👍

[@MikeDawson1]

I assume the bad vibrations are from the aluminum dummy propellers, when you buy real props they should be properly balanced I always mount flight controllers with 3M double sided tape to reduce vibrations that reach it, maybe you could use two layers of that?

[@scarakus]

That's a pretty engine.

[@paranoiia8]

Yeah that engine maybe work ok, but is it best for that project? hmm... Also I wonder, taking in to the account weight of everything, frame, load etc and power it need to fly... how big battery pack would need to be to if you would use for example those more typical conversion electric engines for bikes(most are like 48V or 72V/ 2kW or 3kW that weight around 13Kg)

[@chuckcrunch1]

what about large brushless motors and 80 kg of battery's

[@denvernow7294]

I bet putting a small induction fan under the radiator would lower the temps.

[@terrycrooke1]

Fasinating.. as always !!

[@Convolutedtubules]

Looks to me a bit like a flying industrial mixer or blender.

[@Convolutedtubules]

Impressive nonetheless.

[@BShandyman]

Especially if someone stands too close haha

[@eelcohoogendoorn8044]

I wonder if a hybrid setup would make sense; a generator set without direct mechanical coupling would be easier to isolate the vibrations, and it could be relatively small since it wouldnt be designed for peak power. Then again I suppose it makes more sense for cars, since I imagine in a helicopter-like design such as this, peak power and typical power are not all that different? Not sure... if you need a sudden RPM change to accomodate a manouver that might actually be quite the power spike? if the combustion engine was rated to just barely keep it airborne without acceleration, how many kgs of it would you need, and would it make up for the generator weight and losses? For sure you could run it at very constant rpm and you would not really have any peak thermal loads on it either; so that might simplify things in some ways, such as the cooling.

[@pimplequeen2]

Quite a large weight penalty for hybrid systems, even a simple short run "booster" has a hefty weight penalty.... Complex dual purpose motor/gen + batteries.

[@eelcohoogendoorn8044]

​@@pimplequeen2 Penalty compared to what is the question I suppose. Obvious youd design such a setup with minimal battery capacity; the point wouldnt be to use use as little fuel as possible; but to gain the superior controllability and mechanical simplicity of electric motors. Without batteries, an electric drivetrain is infinitely lighter than a combustion drivetrain. So from that perspective it makes sense to have combustion handle the base loads and let electric supply the peaks. It should save you a lot of spare combustion motor capacity that you would otherwise need to handle peak loads. The only 'extra' component in such a system that is more than the sum of the other parts would be the generator; but if thats engineered for flying like the motors are, it also shouldnt have to be the end of the world. Of course you could also have a hybrid drivetrain where the motor is mechanically connected to the props; but that would also negate some of the benefits.

[@pimplequeen2]

@@eelcohoogendoorn8044 The polini 202 is 33hp (24kw) and weighs 22kg (assume about a 5kg per hour fuel burn) Id be interested in seeing the weight and runtime of an electric motor / generator / batteries and IC engine equivalent. Drone type flight is already very inefficient... Cant be throwing power away :)

[@eelcohoogendoorn8044]

​@@pimplequeen2 Electric drone motors easily have 5x that power density. With batteries it quickly starts looking less favorable; but again such a hybrid system should be designed to carry almost all its energy as hydrocarbons, not as batteries. Conversion losses of the generator also need not be terrible I think. As long as they can run at their optimum design point all the time, permanent magnet motors/generators can have really high efficiencies. Note that you wont be needing any backup combustion if you use a generator; the electric motors should be powerful enough to turn the props by themselves, so as long as the batteries are big enough to land safely, you should be good.

[@pimplequeen2]

I did a rudimentary weight costing for a 4kw 15 second launch booster for a sub70kg fixed wing ultralight I am half way through building. Even with the outrunner built into the IC output pulley and a very efficient four stroke IC, it added more weight than I could afford... Any addition to that 15 second adds more battery weight (I will have to put up with a longer takeoff roll / 100m instead of maybe 25m) It will fly for approx 4 hours on ten liters of fuel, if I lose 3kg of fuel to accommodate the booster weight, I lose almost half my flight time to gain a short field launch ability. Its not a fair comparison but the balancing of conflicting concerns is a reasonable example. Conceptual ideas are often perfect until its time to pick up the spanners and start implementing... For me, the weight issue is a legal one, for a drone type aircraft I think it would be an issue of flight time/efficiency unless it is also aiming for the Sub70kg class...? A 30 min flight "might" be possible with IC and mechanical controls, it seems to me that any departure from that would cut into that flight time via the additional weight and conversion losses.

[@andrewv.157]

I am surprise by the look of the blades

[@FlyXenonRC]

Really awesome stuff

[@SAG1028]

Think a turbo-prop setup would be more efficient.

[@WhiskyMystery]

More great stuff

[@Tarbard]

I was amazed

[@bullygram]

What do you do for living? Aerospace engineer, working at Tesla?

[@tageborg]

His job is literally to inspire the next generation of Swedish kids to become engineers.

[@arnauguillaumes8287]

Absolutely awesome

[@anthonyjames45]

Use pipe spring to bend 25mm

[@anthonyjames45]

Measurements from corner to corner Cross section measurements

[@arlaban22]

THE KILLING MACHINE

[@southborders2916]

Wow, so interesting, keep going 💥

[@FroggyFrog9000]

cool

[@юрийдоценко-х5ж]

Если, эта конструкция для полета, то пилот будет испытывать сильный потока в воздуха от винта... Или , это аппарат без пилота?

[@karacho1]

this looks really dangerous...

[@shurmurray]

4-stroke engine actually vibrates more than 2-stroke. Just saying )

[@anthonyjames45]

That's a workshop

[@willwashere8341]

❤️

[@waynethomas3638]

you needed a tube roller not a bender

[@scarakus]

Another Meat grinder.. lol Nice.

[@makoado6010]

hungarian ww1 helicopter: pkz-1

[@ReiKrisRazo]

Huh

[@johnarizona3820]

^5

[@michaelprice3031]

First comment! cant wait to watch

[@pat14162]

Pfff... a waste of time... n'importe quoi !!!

[@captainTubes]

You need one of those magic electric motors that gets 300 horses into cake tin. They set a coke can by it in the thumbnails. Then, you need to get a gigantic LiFePo4 bank to power through a HV brushless controller with super Low low voltage cut-off to take advantage off the chemistry 🧪 benefits.

[@captainTubes]

Silence is golden 💛🌆🌌

[@onjofilms]

He said in the video, he wants longer run time than a electric motor/battery set up would give. Pay attention.