Mercedes-Benz, with its YASA (Yokeless and Segmented Armature) motor, has achieved a second world record this year for power density. Pulling 1,000 horsepower from a 12 kilogram (xx pound) motor seems a bit incredible, but Mercedes has dynomometer tests to prove it.
This efffort will be in production cars within a year, according to Mercedes, and the aircraft version, produced by a division called Evolito, will probably follow shortly thereafter.
YASA’s spinoff firm Evelito makes makes axial-flux aviation motors. Their D1700 Model puts out 250 kW (305 hp.) at 1,600 rpm. For a weight only 30 kg. (66 pounds). More on Evelito soon.
Even while under development at Oxford University, the motor showed great promise, as well as great torque. This blog included the video below in 2010, with a Lotus 7 copy being flung about handily with two 40 kilowatt (53.6 horsepower) YASAs driving the rear wheels. At that time, power was limited to 75 kilowatts (100.5 hp.), although designers believed 150 kW (201 hp.) was possible. That early motor weighed 11 kilograms, or 23.2 pounds, one pound per three limited horsepower, one pound per six horsepower at the design limit. As driven in the video, the power to weight ratio was more modest, 2.3 horsepower per pound. Even today, it’s an impressive demonstration.
15 Years Later
One kilogram (2.2 pounds) heavier, but nearly 19 times more powerful than the units demonstrated on the Lotus replica, the newest YASA motor now puts out 750 kilowatts (1,005 horsepower).
Road and Track, reporting on MSN.com, explains, “YASA’s previous record-holding device revealed back in June saw it build a 13.1-kilogram motor that made 550 kilowatts. The new motor it’s touting this time around weighs only 12.7 kg, and is capable of 750 kW. That pushes the density record from 42 kW/kg to 59 kW/kg. To put that in freedom units, it’s a 28-pound electric motor that can push out 1005 horsepower.”
YASA motor weighs 28 pounds, delivers 1,005 horsepower. Compare that to a typical 300 horsepower V-8 in an American car
No Exotic Materials
Perhaps the best news is that the line of YASA motors uses no exotic materials. YASA claims to use no rare earth minerals, eliminating the need to deal with unreliable supply sources and potential tariffs. YASA has come up with some in-house solutions. “…By segmenting the axial flux motor in discrete “pole-pieces”, … the motor could be manufactured using Soft Magnetic Composite material.
Mass-poroduced pressings of YASA SMC (Soft Magnetic Composite Material) take place of time-consuming windings
“SMC can be pressed at low cost into a wide variety of 3D shapes. This removed the need for the complex laminations, overcoming the major manufacturing challenge of the axial flux machine.
“It also dramatically simplified the winding and ultimately transformed the cooling capability.”
What This Could Mean for Future Flight
Conventional aircraft design wisdom a few decades ago argued that dropping a pound from powerplant weight could allow dropping two pounds from the airframe/ This virtuous cycle would seem ripe for fulfillment with YASA’ and Evelito’s motors. Lighter airframes or greater allowance for energy storage could have a significant place in future electric aircraft.
Comments 2
Hello,
As an aeronautical engineer, I design, calculate, and flight-test several new light sport aircraft, including flying wings. I was a friend of Chris Heintz and Jim Marske…
I saw that you are interested to electric light aircraft developpment…and I have a proposal that might interest you.
My latest creation is a slightly modified Mitchell wing – the Firebird wing – notably for its wing area of 15 m² with an 18-degree leading edge angle. It’s powered by a Geiger HPD 32 electric motor, producing 32 kW / 120 kg of static thrust, with four battery packs for a level flight time of over an hour. These are the best electric motors currently available on the market – see the geiger web site: https://www.geigerengineering.de/en/e-drive/new-developments
The wings separate 1 meter from the center for easy transport on a trailer. The wing’s strength is calculated at over 10 G at break, with flight limits of +/-7 G. The pilot lies prone inside the wing, as on Horten flying wings… See PDF https://drive.google.com/file/d/1MG0ezjs_87v_TkL7sCOZZn6dWtIXbG–/view?usp=sharing and video below.
The wing’s strength and configuration allow for aerobatic https://youtu.be/fvosxZa7FYk?si=2zxpXMcdXpPKN8fd and/or a two-seater version with a flight limit of +/- 5G.
Regarding the somewhat unconventional prone position, I plan to convert it – easily done – into a standard Mitchell Wing B10 single or two-seater, with the pilot under the wing, or into a Mitchell Wing U2 with the pilot seated inside the wing – see the magnificent virtual Mitchell Wing U2 YouTube video: https://www.youtube.com/watch?v=MCGk93M9vgs
A few weeks ago, I conducted the first test flights, and the wing flies perfectly – see video:
https://drive.google.com/file/d/1a9CqHqwvM7LOQ9C3HKGxarfK4ttj3A0r/view?usp=drive_link
The problem is that I now live in southern Spain, and ultralight aircraft are prohibited in that country (!) except on private airfields, whose runways are all approximately 300m long, of poor quality, and without hangars. Furthermore, you can only fly below 300m above ground level! So, I have to travel to France to fly… each time it means taking a plane and renting a car, no workshop available, etc. This is incompatible with developing a prototype!
Therefore, I’m abandoning the project and will be posting an ad to sell my flying wing. Before posting this ad, I thought my Firebird Wing might interest you. The wing has been 3D modeled with all the ribs available in a DXF file, ready to be sent to a machining center. For the cockpit, you simply need the fuselage of a glider and use it like a mold, whether it’s been in a crash or not, including its canopy.
I prefer to entrust this project to a serious and experienced company like yours, rather than a hobbyist…
I am selling this wing, frame only and/or with the motor and trailer, for the price of the equipment. Complete wing frame: €18,000. New HPD 32 motor with four 60Ah battery packs, ADI interface, and a 3-blade Helix carbon propeller: €19,500. Covered trailer with electric winch: €3,500. Included in the price, I also provide you with all the detailed construction plans, as well as the rights to use, operate, and market a device built according to these specifications. I will also be available to advise you or assist you with the construction of your prototype or any other modifications you may require.
Please feel free to contact me for further details.
Sincerely, Dominique
Author
This is an interesting-looking project. Because the blog cannot endorse products, in order to maintain objectivity and our tax-free status, we cannot comment furhter than this. Readers intereested in Domineque’s wing may contact him personally.