> The motor’s performance on the dyno has exceeded even our most optimistic simulations
Not to take away from the exciting achievement, but I always found comments like this kindof unusual. Really, it exceeded even your _most optimistic_ simulations? If the high end of your simulated performance was below what you actually measured, I am worried that your simulation is seriously neglecting something. I used to work in decent depth with three phase bldc motors, so I feel I can say with some authority that these things _can_ be simulated, and while real world data is hard to exactly predict, getting something outside of the predicted range would generally be interpreted as a sign that your simulation isn't so good. But maybe this is just marketing-speak, and their simulations are actually totally fine.
> and while real world data is hard to exactly predict, getting something outside of the predicted range would generally be interpreted as a sign that your simulation isn't so good
or, yasa is moving very quickly,and as they are breaking new ground in power density, the numbers are ridonkulous,completly and utterly insane, 30lb's peak over 1000hp,just having the thing not vaporise itself is an achivement, and so there is no actual way to simulate that, outside of rocket motors, which is kind of where they are at.
bet the tire guys are shaking there heads
Extraordinary claims and all that. Of course you can simulate it. If you are this surprised by the outcome of an experimental setup the first thing you should do is distrust the data. Figure out where the discrepancy is. Fix it, re-run the simulation and the experiment until the two are in agreement. Then publish.
The normal scientific reflex is not to hit the marketing guy and say 'we've got a winner, go write it up'.
I suspect that the marketing guy's eyes glazed over when the engineers tried to explain confidence intervals to him. He demanded a simple figure. They gave him the median projected value to make him go away. The tested value was above median projection and thus you get this wordspew.
> I used to work in decent depth with three phase bldc motors, so I feel I can say with some authority that these things _can_ be simulated
If I take it literally versus hyperbole and excitement, could there be uncertainty coming from the drive train design choices, system integration details?
Sure, but that sort of uncertainty should only increase the range of values you see out of the simulation. You could say “efficiency may range from 60% to 80%, so the output torque will range from X to Y”. If the real result is bigger than Y, something has gone wrong in your modeling or assumptions
> something has gone wrong in your modeling or assumptions
Maybe they used a "all our previous tests showed 95% of efficiency compared to simulation, so let's multiply all our results, including top efficiency by this". Then their newest motor had 97% efficiency comparing to previous model.
Meh, depends what's the goal.
Exceeding predicted performance is not a screw up, it's just providing a minimum guaranteed performance aka playing it safe (under promise, over deliver).
Also, we don't know by how much the most optimistic predicions were exceeded.
Short-term peak ratings for electric motors are always huge. You can put in higher voltages up to arc-over. More interesting is sustained output. 1 minute, 10 minutes, 1 hour, continuous duty. That's all about how well it can get rid of heat.
That's why electric motors have a "temperature rise" number on the data plate. That's the steady-state temperature increase from a cold start when run continuously at rated power.
To be fair, in some applications the short-term peak rating is an important metric in its own right. For example, robotics applications frequently will have high peak load, but much lower steady state load. Eg, a jumping robot will briefly need a ton of force when pushing against the ground and when landing, but in the middle there it won't be applying such high loads. Likewise for bringing appendages up to speed, or accelerating a car to some speed, etc.
edit: After looking at your account, I see you are John Nagle, and I worry that I am confidently-incorrect here, lol. I'll leave the comment as-is because it is still my genuine belief, but feel free to correct me if I'm totally off!
There's a series of limitations on peak motor torque. Motors usually hit the thermal limits first, but here are some of the other limits:
A big problem with older permanent magnet motors was that too much current could produce a field strong enough to demagnetize the magnets. Supposedly this is is less of an issue in the cobalt-neodymium magnet era, because the coercivity of those alloys is so high.
Then there's finding a pulsed current source to power the windings. Ultracapacitors are good for that.
Then there's finding big enough semiconductors to switch the thing. This, too, has become much easier. It's amazing how much current you can put through modern power MOSFETs.
Then there are mechanical limitations. At some point, something is going to bend from sheer torque. At some point below that, the windings will distort a little on each cycle and wear out.
Applications for this include railguns, catapults, and electrically launched rollercoasters. Interestingly, they're all linear motors.
(I haven't looked at this since the 1990s. The components needed are now far better and more available. Mostly as a spinoff of the electric car industry.)
> To be fair, in some applications the short-term peak rating is an important metric in its own right.
Cars are a good example of this. There are very few public roads in the world where a car can use 1000hp for more than a few or perhaps a few tests of seconds at a time. On a drag strip a 1000hp street car might run a low 9 second quarter mile reaching around 150mph. That'll put you in jail if a cop sees you doing that speed in a lot pf places. To maintain the fastest speed limit in most countries probably doesn't even require 100hp. So a "short term peak rating" that lets you use 1000hp for 10 seconds will accelerate you in a _very_ "sporting" fashion for as long as you're likely to be able to hold the accelerator down (outside of a race track or autobahn).
Back when I raced quadcopters, I'd happily set them up to pull 200% or more of the rated power of the motors and batteries, because if you kept it pinned at full throttle it would have vanished out of sight within 2 seconds. (You had to be somewhat more circumspect with the motor controllers, the magic smoke could come out of those way faster - sometimes going pop effectively instantly if you started to approach 150% of rated capacity, sometimes even 120% would blow them up ij just a few hundred milliseconds.)
In the press release, they mention 350-400 kW continuous power. The motor weight is given as 12.7kg so this translates to 27.6-31.5 kW/kg (16.76-19.2 hp/lb) continuous power.
What always shocked me were the number of tech-oriented people that were are not aware of the tremendous progress in lithium ion batteries. And not just in the cost, performance, and reduction in materials needed. Production capacity grows by 10x in a mere five years. We were at 1.2TWh of production in 2024, and will be at ~20TWh in 2030. When batteries are eventually recycled, they get recycled into a higher power capacity than went in because recovery of materials is high and gains in production are even higher.
The global average cost of solar panels is $90/kW. With high tariffs, it's $150/kW in India and $270/kW in the US. Raising tariffs is something like 6 months of price drops. (Meanwhile installed, it costs $500-$3000 on residential properties...)
Solar and storage are some of the most impressive technologies of the past century, and so many people are sleeping on the huge changes it will have.
> The global average cost of solar panels is $90/kW.
I don't remember where I read about it first, but the fact that Pakistan is installing gigawatts of solar panels per year made me smile. It's not a coordinated effort, either; people choosing between (1) relying on janky transmission lines, (2) feeding a diesel generator, and (3) buying a rectangle that creates electricity and a cheap battery tend to choose option 3.
Oh I'd really hope not, who wouldn't want higher capacity 18650 cells? Maybe they wouldn't be VTC-6, but those are the highest capacity cells I've managed to find!
No, the BMC tends to not care about capacity. You'd maybe need to change the software, but because the capacity changes over the lifetime of the battery, the BMC tends to go by voltage anyway.
I think these days the solar panels and even batteries are quite cheap, but the equipment needed build a hybrid system for a house is still a mess. One can find the right inverter, but not a good match for the battery, the backup/switching system that needs to match, DC fuse boxes, especially for European systems that are 230V and sometimes 3-phase, the progress is not good enough even if the problem is simple enough.
In the low-tens of kg, I have to wonder if we will just start mass-producing a single motor and just change the driving electronics for different vehicles/applications. Eg: De-rating this motor via driving electronics for aviation to only produce 200hp would be interesting for experimental designs.
Highly unlikely, but since you make the claim I think you also should present that whole system evidence. From what little I know as a once upon a time bit player in aviation I suspect that that will be a very hard sell.
For instance: I know of an invention that will spin up the wheels of a landing aircraft just before touchdown. This saves on the wear of the tires (right now it is mostly the runway that spins them up, as a result of which you see these nice rubber deposits on the touchdown areas). But it would add a few kg to the weight of the wheels so it's a complete non-starter.
At what point can we just return to 1990s wheel sizes, add the motor to the wheel, and have the same unsprung mass as we have with today's gigantic wheels?
Elaph and Protean are the well known in-wheel-motor producers now and some other companies have done in-house versions.
That teardrop-shaped EV [Ed: Aptera] was going to use the Elaph ones but I think there was some issue with producing enough of them or something like that.
Protean wheels will be on the new Renault 5 Turbo3E which will be a high performance, expensive, short production run.
They make it "easy" to electrify a petrol car and there's a few Sandy Munro videos about the Protean wheels where they test drive a Mercedes converted to and EV with them. Munro was contracted to find ways to get the manufacturing cost down without reducing the durability too much.
You might think that YASA motors would be extra useful for IWM applications where lightness is important but there are other constraints such as durability and fitting in the electronics and it might be essential to have a completely custom design. I don't really know but I do think they should be working together in an ideal world.
Putting the motor in the wheel does have some performance and space advantages. It is being done in some vehicles today.
However it does have some limitations as well. For the "general case" it may not be ideal.
Top of the list is protection. The motor is an expensive part, the wheel is an exposed part - bumping a curb for example could get expensive quickly.
Cooling is also an issue. In-wheel motors suggest air cooling, whereas a bigger (single) motor can be liquid cooled.
Currently in wheel motors end up being quite a bit more expensive (because 4 motors not 1).
On paper, in-wheel motors save space, allow for concepts like "4 wheel drive with different lock", save weight and cleaner design (no drive shafts etc), but it's not clear that the end product is better for "every day" users.
As soon as the roads are as smooth as they were in the 90s. I have a pet theory that wheels have gotten huge partly in response to deteriorating roads - larger diameter means less leverage against the suspension when hitting defects. It’s the same reason dirt bikes have large front wheels.
The aspect ratio (sidewall height) of tires has decreased in a lot of vehicles though. They are driving around with low profile rubber bands on the rims. Looks cool, but not much fun in the potholed mid-west.
I want rear wheel steering with 7m turning radius, 4m cars to have same cabin space as 4.5m ICE cars, seats in last row of a 3-row not constrained why wheel wells and axles as an Indian on congested roads. 160 HP is dangerous enough.
The weight and form factor looks excellent for small propeller planes. Yes, batteries are heavy, but the lightweight of the motor makes room for more batteries.
A typical Rotax 912 with accessories goes over 55 kg for 80 HP max and ~ 60 HP cruise. The 100 HP/75 HP version is around 65 kg. The same continuous power with this technology looks like a 5 kg motor and 60 kg of batteries for a direct replacement, if we consider the regular fuel tanks of 50-100 kg on some planes (I used to fly a plane that took 140 liters of fuel with a 100 HP Rotax, but it was modified) then there is enough battery for a flight school needs.
> The motor’s performance on the dyno has exceeded even our most optimistic simulations
Not to take away from the exciting achievement, but I always found comments like this kindof unusual. Really, it exceeded even your _most optimistic_ simulations? If the high end of your simulated performance was below what you actually measured, I am worried that your simulation is seriously neglecting something. I used to work in decent depth with three phase bldc motors, so I feel I can say with some authority that these things _can_ be simulated, and while real world data is hard to exactly predict, getting something outside of the predicted range would generally be interpreted as a sign that your simulation isn't so good. But maybe this is just marketing-speak, and their simulations are actually totally fine.
> and while real world data is hard to exactly predict, getting something outside of the predicted range would generally be interpreted as a sign that your simulation isn't so good
Either that, or your measurements are inaccurate.
or, yasa is moving very quickly,and as they are breaking new ground in power density, the numbers are ridonkulous,completly and utterly insane, 30lb's peak over 1000hp,just having the thing not vaporise itself is an achivement, and so there is no actual way to simulate that, outside of rocket motors, which is kind of where they are at. bet the tire guys are shaking there heads
Extraordinary claims and all that. Of course you can simulate it. If you are this surprised by the outcome of an experimental setup the first thing you should do is distrust the data. Figure out where the discrepancy is. Fix it, re-run the simulation and the experiment until the two are in agreement. Then publish.
The normal scientific reflex is not to hit the marketing guy and say 'we've got a winner, go write it up'.
+1
I suspect that the marketing guy's eyes glazed over when the engineers tried to explain confidence intervals to him. He demanded a simple figure. They gave him the median projected value to make him go away. The tested value was above median projection and thus you get this wordspew.
> Make him go away
Spoken like a true engineer.
> I used to work in decent depth with three phase bldc motors, so I feel I can say with some authority that these things _can_ be simulated
If I take it literally versus hyperbole and excitement, could there be uncertainty coming from the drive train design choices, system integration details?
Sure, but that sort of uncertainty should only increase the range of values you see out of the simulation. You could say “efficiency may range from 60% to 80%, so the output torque will range from X to Y”. If the real result is bigger than Y, something has gone wrong in your modeling or assumptions
> something has gone wrong in your modeling or assumptions
Maybe they used a "all our previous tests showed 95% of efficiency compared to simulation, so let's multiply all our results, including top efficiency by this". Then their newest motor had 97% efficiency comparing to previous model.
Depends if you make overly conservative assumptions in your modeling...
If you have simulations with varying levels of optimism, but all of them were too conservative, then you screwed up.
Meh, depends what's the goal. Exceeding predicted performance is not a screw up, it's just providing a minimum guaranteed performance aka playing it safe (under promise, over deliver).
Also, we don't know by how much the most optimistic predicions were exceeded.
Makes for nice marketing ;)
"short-term peak rating"
Short-term peak ratings for electric motors are always huge. You can put in higher voltages up to arc-over. More interesting is sustained output. 1 minute, 10 minutes, 1 hour, continuous duty. That's all about how well it can get rid of heat.
That's why electric motors have a "temperature rise" number on the data plate. That's the steady-state temperature increase from a cold start when run continuously at rated power.
To be fair, in some applications the short-term peak rating is an important metric in its own right. For example, robotics applications frequently will have high peak load, but much lower steady state load. Eg, a jumping robot will briefly need a ton of force when pushing against the ground and when landing, but in the middle there it won't be applying such high loads. Likewise for bringing appendages up to speed, or accelerating a car to some speed, etc.
edit: After looking at your account, I see you are John Nagle, and I worry that I am confidently-incorrect here, lol. I'll leave the comment as-is because it is still my genuine belief, but feel free to correct me if I'm totally off!
There's a series of limitations on peak motor torque. Motors usually hit the thermal limits first, but here are some of the other limits:
A big problem with older permanent magnet motors was that too much current could produce a field strong enough to demagnetize the magnets. Supposedly this is is less of an issue in the cobalt-neodymium magnet era, because the coercivity of those alloys is so high.
Then there's finding a pulsed current source to power the windings. Ultracapacitors are good for that.
Then there's finding big enough semiconductors to switch the thing. This, too, has become much easier. It's amazing how much current you can put through modern power MOSFETs.
Then there are mechanical limitations. At some point, something is going to bend from sheer torque. At some point below that, the windings will distort a little on each cycle and wear out.
Applications for this include railguns, catapults, and electrically launched rollercoasters. Interestingly, they're all linear motors.
(I haven't looked at this since the 1990s. The components needed are now far better and more available. Mostly as a spinoff of the electric car industry.)
> To be fair, in some applications the short-term peak rating is an important metric in its own right.
Cars are a good example of this. There are very few public roads in the world where a car can use 1000hp for more than a few or perhaps a few tests of seconds at a time. On a drag strip a 1000hp street car might run a low 9 second quarter mile reaching around 150mph. That'll put you in jail if a cop sees you doing that speed in a lot pf places. To maintain the fastest speed limit in most countries probably doesn't even require 100hp. So a "short term peak rating" that lets you use 1000hp for 10 seconds will accelerate you in a _very_ "sporting" fashion for as long as you're likely to be able to hold the accelerator down (outside of a race track or autobahn).
Back when I raced quadcopters, I'd happily set them up to pull 200% or more of the rated power of the motors and batteries, because if you kept it pinned at full throttle it would have vanished out of sight within 2 seconds. (You had to be somewhat more circumspect with the motor controllers, the magic smoke could come out of those way faster - sometimes going pop effectively instantly if you started to approach 150% of rated capacity, sometimes even 120% would blow them up ij just a few hundred milliseconds.)
I always remember the cool falling bodies animation Animats had in /.
In the press release, they mention 350-400 kW continuous power. The motor weight is given as 12.7kg so this translates to 27.6-31.5 kW/kg (16.76-19.2 hp/lb) continuous power.
It's just amazing how over the past 10 years it's like the whole world rediscovered electricity.
What always shocked me were the number of tech-oriented people that were are not aware of the tremendous progress in lithium ion batteries. And not just in the cost, performance, and reduction in materials needed. Production capacity grows by 10x in a mere five years. We were at 1.2TWh of production in 2024, and will be at ~20TWh in 2030. When batteries are eventually recycled, they get recycled into a higher power capacity than went in because recovery of materials is high and gains in production are even higher.
The global average cost of solar panels is $90/kW. With high tariffs, it's $150/kW in India and $270/kW in the US. Raising tariffs is something like 6 months of price drops. (Meanwhile installed, it costs $500-$3000 on residential properties...)
Solar and storage are some of the most impressive technologies of the past century, and so many people are sleeping on the huge changes it will have.
Right now in India, a 3kWh solar on grid system costs after subsidty a whopping USD $650 OR INR60000.00
The on grid includes panels On grid inverter Wiring Instslation and earthing
> The global average cost of solar panels is $90/kW.
I don't remember where I read about it first, but the fact that Pakistan is installing gigawatts of solar panels per year made me smile. It's not a coordinated effort, either; people choosing between (1) relying on janky transmission lines, (2) feeding a diesel generator, and (3) buying a rectangle that creates electricity and a cheap battery tend to choose option 3.
Unfortunately this means the government is going bankrupt keeping power generation online for non-solar/evening only users.
And yet my VTC-6 are still the same capacity as five years ago :(
hah, well it appears that the capacity may be part of the standardization for that?
Oh I'd really hope not, who wouldn't want higher capacity 18650 cells? Maybe they wouldn't be VTC-6, but those are the highest capacity cells I've managed to find!
If they changed it you'd need a new BMC, right?
No, the BMC tends to not care about capacity. You'd maybe need to change the software, but because the capacity changes over the lifetime of the battery, the BMC tends to go by voltage anyway.
I think these days the solar panels and even batteries are quite cheap, but the equipment needed build a hybrid system for a house is still a mess. One can find the right inverter, but not a good match for the battery, the backup/switching system that needs to match, DC fuse boxes, especially for European systems that are 230V and sometimes 3-phase, the progress is not good enough even if the problem is simple enough.
High power high voltage switching ICs have caught up.
In the low-tens of kg, I have to wonder if we will just start mass-producing a single motor and just change the driving electronics for different vehicles/applications. Eg: De-rating this motor via driving electronics for aviation to only produce 200hp would be interesting for experimental designs.
Then you could use a smaller motor which would be lighter (important for aviation) and likely cheaper.
Looking at the whole system might reveal a different answer though.
Highly unlikely, but since you make the claim I think you also should present that whole system evidence. From what little I know as a once upon a time bit player in aviation I suspect that that will be a very hard sell.
For instance: I know of an invention that will spin up the wheels of a landing aircraft just before touchdown. This saves on the wear of the tires (right now it is mostly the runway that spins them up, as a result of which you see these nice rubber deposits on the touchdown areas). But it would add a few kg to the weight of the wheels so it's a complete non-starter.
Is there a chart or table somewhere for this benchmark, so one can compare the performance of many different available motors?
Our Chevy Bolt EV has a real-time display of... something, a number in units of kW. I presume it's approximate instantaneous battery discharge rate.
Anyhow, I rarely see more than 35 kW indicated for less than a minute at a time.
So can I get my 59kW/kg to go, please? I will take two kilograms.
FWIW:
Is this from a lab or a production unit? Because if it's just lab results, they don't really mean anything.
At what point can we just return to 1990s wheel sizes, add the motor to the wheel, and have the same unsprung mass as we have with today's gigantic wheels?
Elaph and Protean are the well known in-wheel-motor producers now and some other companies have done in-house versions.
That teardrop-shaped EV [Ed: Aptera] was going to use the Elaph ones but I think there was some issue with producing enough of them or something like that.
Protean wheels will be on the new Renault 5 Turbo3E which will be a high performance, expensive, short production run.
They make it "easy" to electrify a petrol car and there's a few Sandy Munro videos about the Protean wheels where they test drive a Mercedes converted to and EV with them. Munro was contracted to find ways to get the manufacturing cost down without reducing the durability too much.
You might think that YASA motors would be extra useful for IWM applications where lightness is important but there are other constraints such as durability and fitting in the electronics and it might be essential to have a completely custom design. I don't really know but I do think they should be working together in an ideal world.
They are apparently getting the cost down to where we might start to see them in more affordable vehicles: https://www.proteanelectric.com/protean-showcasing-iwm-techn...
Putting the motor in the wheel does have some performance and space advantages. It is being done in some vehicles today.
However it does have some limitations as well. For the "general case" it may not be ideal.
Top of the list is protection. The motor is an expensive part, the wheel is an exposed part - bumping a curb for example could get expensive quickly.
Cooling is also an issue. In-wheel motors suggest air cooling, whereas a bigger (single) motor can be liquid cooled.
Currently in wheel motors end up being quite a bit more expensive (because 4 motors not 1).
On paper, in-wheel motors save space, allow for concepts like "4 wheel drive with different lock", save weight and cleaner design (no drive shafts etc), but it's not clear that the end product is better for "every day" users.
As soon as the roads are as smooth as they were in the 90s. I have a pet theory that wheels have gotten huge partly in response to deteriorating roads - larger diameter means less leverage against the suspension when hitting defects. It’s the same reason dirt bikes have large front wheels.
The aspect ratio (sidewall height) of tires has decreased in a lot of vehicles though. They are driving around with low profile rubber bands on the rims. Looks cool, but not much fun in the potholed mid-west.
After he destroyed his 3rd ultra-low-aspect tire in one year, my dad got smaller wheels for his Golf R.
I want rear wheel steering with 7m turning radius, 4m cars to have same cabin space as 4.5m ICE cars, seats in last row of a 3-row not constrained why wheel wells and axles as an Indian on congested roads. 160 HP is dangerous enough.
motors do not like the impact loads that wheels see, which is why bicycles with hub motors do not have a long lifespan
As an aside, yes the current trend of huge wheels with super low profile tires is idiotic. Hopefully sanity will prevail at some point.
The weight and form factor looks excellent for small propeller planes. Yes, batteries are heavy, but the lightweight of the motor makes room for more batteries.
A typical Rotax 912 with accessories goes over 55 kg for 80 HP max and ~ 60 HP cruise. The 100 HP/75 HP version is around 65 kg. The same continuous power with this technology looks like a 5 kg motor and 60 kg of batteries for a direct replacement, if we consider the regular fuel tanks of 50-100 kg on some planes (I used to fly a plane that took 140 liters of fuel with a 100 HP Rotax, but it was modified) then there is enough battery for a flight school needs.
https://evolito.aero/electra-selects-evolito-to-supply-elect...
This is a spin-off company from YASA whose purpose is to supply them for aircraft together with other bits.
The world speed record for electric aircraft is held by an aircraft with 3 YASA motors:
https://www.youtube.com/watch?v=4hapBP-Cdis&t=418s&pp=0gcJCd...
The future is here - https://www.pipistrel-aircraft.com/products/velis-electro/
Seeing these pop up at a lot of flying schools for basic training.