What a beautiful video - Incredible engineering, clear explanations, and a father son project. Doesn't get much better than that! Great work both of you, a well deserved record.
Think i found my new favorite channel. Having in depth technical description and great prodcution is rare nowadays, great to see the design process, would never have thought to test aerodynamics out of a window haha. Keep making videos this good, and analysis this engaging.
Small drones are practically undetectable and inescapable at much more conservative speeds anyway. Being cheap, easy, high range and having resilience to jamming would be more important than 500kph+ speed.
Been slightly obsessing about this cool thing so here's some calcs for interest's sake: If we look at the power consumption at 360km/h (100m/s) which is 5091We, assuming about 85% motor efficiency and 55% propeller efficiency we arrive at drag force of 23.8N. This can be reduced to a CdA figure of around 0.00396. Eyeballing the design section area of 150mm x 120mm gives us an A of 0.018m^2 yielding a drag coefficient (Cd) of about 0.22 or approximately that of a Tesla Model 3. This is kind of impressive except that it has no wheels, wheel arches or tyres which are one of the dominant forms of drag on a road vehicle so it suggests that there's at least some room and probably plenty for improvement. Also, at max speed of 510km/h we're starting to see compressibility effects being over Mach 0.4 in linear speed so there's no doubt that the propeller blades are well into the transonic flow regime so the 55% propeller efficiency above may be an overestimate. To make any appreciable gains in the record speed these problems will only be exacerbated. Time to get busy with area ruling and possibly ducted fans to improve the total aero efficiency. I also note there is appreciable voltage sag at the high speed run dropping down to 34V. This means that, for an assumed 12S system voltage of 44.4V nominal, there's about 2kW of power disappearing into the wiring as heat. (235A at 10V sag > 2kW). While motors are to some extent immune from increasing voltage from an efficiency perspective, the rest of the electrical system surely isn't, so bumping the voltage higher is only going to be a win, albeit with safety complications.
@@matthewbarnard461 Some of it is, for sure, but it depends on how and where the voltage is measured. Also it's still I²R losses which is just turning battery power into heat so increasing system voltage can only but reduce this inefficiency.
Hey, I remember this guy called me on the phone a few years ago for consulting about blender. How you doing Mike? This is seriously cool. I grew up without a father because he was assassinated when I was 2, so I never had this kind of interaction, and even though I'm an amazing engineer I have simply never had access to the tools, space, or resources required to carry out this kind of experiment. To me, you guys are like ultra-rich. You are like infinitely richer than me. We are different classes of human. That's why I am a designer. Pencils are cheap. I have made countless models for other people to 3D print, but they will profit because I can only afford the tools to make the models, but they own the printers, and I will simply never have enough money to own my own printer.
Hey Tom. I cant say I remember talking to a Tom 🤔 do you go by another name? And for the record I also grew up without a father which is why I treasure my sons all the more.
@@Mike-Bell You called me on the phone after my blender tutorial went viral to inquire about Blender consultation, and I gave you a figure that I assume was too high, and you never contacted me again. I'm 100% sure it was you, I might still have your number. I know because I remember your name, voice, and videos. Do you realize what you have made? you've made the next weapon for the Russia Ukraine drone war and you gave the designs to the world for free.
Hey Tom oh yes I found your channel. I remember you. Are you still working for the architecture related company? Don’t let lack of tools define your potential. Your creativity is a powerful tool that many would be envious of.
@@Mike-Bell My father was assassinated when I was 2 and I was accused of Sexual Assault in Cape Town while running two popular comedy shows even though I'm completely innocent. It does not matter how intelligent or talented I am. I have been told since birth that I'm a genius capable of anything. My father was also a genius. It doesn't matter. I live under fascism. There is a boot on my face. I'm telling you, we are different classes of human. I will forever been seen as a crazy person despite the fact that I repeatedly prove myself to be in the top 0.01% for intelligence. I'm telling you I have no power, because I was born a criminal.
@@TommyLikeTom Hi Tom, I'm really sorry to hear about your difficult start in life. Your story is heart-wrenching. However, given your intelligence, you'll understand that dwelling on self-pity can trap you in a cycle that hinders progress and success. Stephen Fry articulates this sentiment beautifully. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-r_2kelqYz_o.htmlsi=dZcWIaX_HwLWtfQ_
Well done guys, this is awesome to have local guys pushing the limits like this, very inspiring! Did you ever consider running CFD on the model, and do you think that would have helped the design direction?
Thanks Mike. Up till this point the level of technology is such that big gains have been possible through iterative exploration. But from here on the gains will become smaller and harder to achieve and require more sophisticated optimisations and we are running wind tunnel simulations for further speed improvements. And we have product manufacturers who are interested in supplying us with optimised components to go faster. If you have CFD skills I would be interested to know how you would approach this.
Thanks I value the concern 😊 and your comment. It more case of with youtube getting 3.7mill new videos uploaded each day that it really takes a lot to stand out above all that noise. But after a couple of years doing this I think this video is going to give me the catapult boost I have been waiting for. The subscribe rate on this video and type of story has gone nuts and is super high which is fantastic recognition for my efforts.
Incredible. The headaches and cost of prototyping and manufacturing on a cnc machine twenty years ago vs. the options of today has mind blowing potential.
Awesome project! Looks like a fun one. Curious if you have done the math for what impact a carbon fiber exterior (or any alternative) could have on weight. The shell sure looks pretty light already.
The low hanging fruit development areas are still batteries and aerodynamics so thats the next version. And interestingly induced drag is near negligible at 500. You pay the price of weight in battery drain and manoeuvring. The angle of attack of 1 degree is all you need for body lift. It’s basically a wingless VTOL. I’ll be explaining this in the next video. So weight savings will increase speed because of a longer speed boost but not induced drag savings. Weight will get serious attention in version 4🤣 And when we get serious competition. 🤙🏻
What an amazing project. I love the father and son team. I'm looking forward to use some of the things I learned from both of you in my next project. Congratulations
This is AMAZING! Congrats on the accomplishment… a good thing that you documented everything, which is a great thing to do in engineering. Great job once again!
From someone who can barely make a paper aeroplane, this is fascinating. Watching the design evolve to optimise the aerodynamics, airflow, and centre of gravity is amazing. It must have been so rewarding seeing it achieve such crazy speeds 😄
in your next design, you can double the amount of motors. 8 instead of 4, same design for the core, space for the battery in the center. 4 more motors on top, feeding the bottom motors, or turn them all 4 45 degrees as to not interfere with the bottom 4 motors. the flight time might be halved, but the speed might increase :) you could make it perfectly symmetrical, modular even, adding more and more motors in a line, even the battery compartment could be modular.
Excellent video! The animations were awesome and that definitely covered everything I would have liked to pick your brain about. It's always nice to hear about others design philosophy. Also I just have to mention some funny coincidences. I'm currently getting my mechatronics degree too, nice job Luke! The other one is that I had originally named my speed record project the peregrine falcon back in 2019. What are the chances?
Amazing engineering skills. You should collaborate with the team of Dronegods. Obviously the F1 drone cam its purpose was not top speed, it's goal was to be able to keep up with an F1 car for around 12Km's (2 laps) while providing stable high quality footage.
I feel almost vindicated seeing someone else do their rapid drone prototyping in Blender, and especially your line that; "Success is achieving both excellence in performance, and esthetics" is something I've cought a lot of heat over from the pure CAD guys. Amazing work all-round!
This is a very interesting take! I feel like engineering/product design is to often teached to go from a sketched based 2D straight into hard and traditionel software such as solidworks/ siemens NX surfacing tool of what ever is used. Blender could be this perfect in the middel. It's abusrd to think about the hours i've seen friends, colleageas including myself put into interrating very complex surface models just modifying splines and addapting surfacecontinuity. The best thing is I have blender installed a couple of months ago exact for this reason but do not seem to find the time or motivaction tot get into it. I this video shows exactly why I should.
This video is awesome! But I suggest changing the Thumbnail to something cooler like nightflying with the green light! Very dramatic scene and super cool!
Awesome design, execution and performance, Mike Your Bambu printer may be able to print STEP files, which will behave like very fine mesh STL files, although that depends on the slicer. Great to see South Africans setting records. Netjies gedaan.
Dankie. Flippin lekker om SA bietjie te showcase. Blender doesnt work with STEP files unfortunately but it is perfect for the animation I make and it makes fantastic drone designs too.
Yup, Bambu Studio does support STEP. That's my go-to format when working with designs that have tight tolerances. Plus they're much easier for others to reverse-engineer.
9:15 "The software generates these elegantly sculpted streamline curves." I am sure you've discussed this elsewhere, I've yet to see your other videos, but what software did you use here?
This is amazing! Is there any chance you would be comfortable publishing the designs so that others might be able to create it, or perhaps sell some kind of kit? I think people (myself included) would probably pay a good deal of money for something like this
You might pick up a little thrust from dissipating internal heat. It will be very small. The key is to pressurize the interior. That's entirely possible, your static pressure at 400 km/hr is 7600 Pa. Put an 18 mm diameter hole at the center of the nose, which will also help with camera clarity when flying forward. You should be able to get nearly perfect static pressure recovery. The lip on that hole really matters. Look at the lips on turbofan inlets. The main thing is not to have a sharp edge that immediately expands outward internally. The air then flows through your body and ejects out the back through a converging duct at the very back (not along the sides if you can avoid that). If your ESCs are 85% efficient, you'll be dissipating 1350 watts in there. YOW! If you want to hold the air temp rise to 40 C, you'll need 34 grams of air per second, or 28 liters/sec. At 400 km/hr, your ambient stream tube is 2.5 cm^2. Expand that to 25 cm^2 through the ESC section and you'll have 40 km/hr air at almost 7500 Pa. Heat by 40 C on a 20 C day will get you 13% expansion. I can't determine the perfect ejector nozzle diameter, but something about 13% larger than the ambient stream tube should do it. Guess 2.75 cm^2 or 19 mm diameter.
Sounds like a great solution. Will definitely investigate this. A hole at the rear is preferable because it shortens the tail reducing the toppling over moment on landing. Plus the batteries need cooling too. As does the flight controller. We are planning a longer tail to close down the air slower and so we can do away with the tail fin and its drag.
Hi Iain Its clear you have expert knowledge. We are investigating relaying the video feed. Do you have experience with that? And it would be nice to talk to you further about the camera system. We had the canopy to prevent the camera from vibrating in the 500kmh airstream but tested an open camera and it didn’t shake. So the open camera is what we want to explore further and that fits with your pressurised inlet suggestion. @lukemaximobell1
Excellent work, Mike! How efficient are your motors at that power level? At 2kW each, it seems like there's highly likely room to improve them at least some and cut your losses giving you more thrust for less heat. An FOC motor controller might yield some efficiency improvements over a trapezoidal sensorless controller too.
The motors did not get overly hot on speed runs. Overheating motors is often a sign of a bad tune and the motors speeding up and slowing down unnecesarily.
Thanks. I am a retired architect and have an Autocad Sketchup Revit Lumion background so Blender is a natural follow on. My primary need is animation so Blender is a must. Besides Blender is fantastic software. It can do pretty much all things 3d. What is your field/ software?
Are there any blender Addons you use to help model it? I have blender for a few years since 8th grade but I still find it extremely difficult to do things like this that involve precise measurements and parameters. Also, was all of the design done in blender? Or dis you also use other programs like cad or other things to help. Thank you! For instance, how did you model things like the camera tilt adjustment? Also, during the part of the video where you showed the short clip of modeling the NACA duct, how were you doing that? What was the greyed out shape you were manipulating? Was it just a boolean or was it something else that i don’t know about?
Yes all modelling and design was done in Blender. I dont use special add-ons. I find the overall dimensions of an object useful for sizing and scaling. And you can set up a special axis for non orthogonal modelling. And you can move and scale inputing numbers. The NACA duct was modelled with booleans.
My university drone team may be attempting this record next fall. Been doing some research, and I want to commend your component selection! It's been really hard finding any configuration that performs higher in thrust simulations.
Maybe tow steered composites and custom aerostructurally optimized geometry of frame and motors for v4? In my experience, ADFLOW is a lot faster and more accurate than airshaper and it can do shape optimization
very, very cool! how are you doing the control mixing? i.e. converting from torque commands to motor thrusts? if by any chance you have a mixer that outputs something like 95% of max thrust + some small differential consisting of roll/pitch/yaw components -- there is something better! using a QP solver you can find the thrust commands giving max forward thrust while still satisfying torque inputs. for such small problems the solution can be found in fractions of a millisecond, even on tiny processors. If you haven't yet done so this might get you another couple kph! get in touch if you wanna know more, i have done something extremely similar at work :)
its simply the mixer in betaflight. there will always be a small loss of power as the pid controller with airmode enabled can only be active and stabilize the quad if it dials back from full throttle on at least one of the motors. this is why its most efficient to make the quad as aerodynamic as possible at the angle of attack its going to fly at and a good tune. since the drone doesnt fly completely straight forward but very slightly tilted up any drag on the body will push the body up and the pid controller will cut power to the bottom motors to compensate.
This has absolutely blown me away in terms of how effective your designing and surfacing was of v2 without doing aero computation. Eagerly awaiting v3!
Having read Hoerner's Fluid Dynamic Drag, it seems to me that your nose tip radius is a bit too sharp for speeds close to mach 0.5 or 0.6. Forward visibility of the camera in the nose would also be improved with a larger radius in the tip of the nose. I have been working with owners of race cars and sport aircraft for 40 years helping them learn aerodynamics for performance in competition.
In general, the idea of such a device is not new,🤷♂️ it was already there, but you guys have brought the project to a really working fast state!👍 Thanks !
I just built my first vertical frame and it flew away on me, it might be because my props are so close together as you were saying. Fascinating to hear more construction detail and the problems you had with your escs. also how you made your camera/nosecone and airshaper fascinating thanks a lot!
The propeller tips in our drone are around Mach 0.8. At Mach 0.85 0.9 the drag rockets up and it like hitting a wall. This is the hard limit. We think around 600 or a little more is achievable. Beyond that near impossible for electric. To get the sheer power to overcome Mach drag you need good ol fuel and oxygen.
At this pont it would make more sense to have less propellers and a more streamlined design, IE to build an RC plane. What qualifies as a drone anyway?
