- kjetil@lemmy.worldEnglish4 hours
Well that sounds terrifying. There’s a reason why the brake hydraulicsystem is actually two separate hydraulic systems, for diagonally opposite wheels. The only single-point-of-failure is the brake pedal.
Their leaving out the critical details on how this will electric system will be fail safe, or even legal.
The announcement was light on details about both the system itself and how its fail-safes are implemented.
Maybe they’ll return to spring actuated mechanical brakes that are released when everything is working. (More common in heavy industry, and I believe also truck brakes)
- grue@lemmy.worldEnglish2 hours
The only single-point-of-failure is the brake pedal.
And even then, only on cars with those stupid electronic parking brakes instead of a proper mechanical emergency brake.
- 3 hours
It would be trivial to keep the car from starting if the brakes don’t pass a system check, and make the main electric motor of the car apply maximum regen braking if the system fails en route.
And you’d have one motor per wheel, so if one fails you still have more than enough braking power.
In principle, a system based on electric motors should be a lot more reliable than one based on hydraulics.
- mlegstrong@sh.itjust.worksEnglish1 hour
Idk it might use magnetic brake pads. I have used them in other fields & they are pretty nifty. The ones I used created eddy currents & had not mechanical wear. For my project the mechanical brake had a ~10 year lifespan while the magnetic brake could last ~50 years. Also the mag brake was only 30% more expensive but didn’t need maintenance & would be significantly cheaper if you took the lifespan of the project.
- Leeks@lemmy.worldEnglish40 minutes
Can eddy current brakes bring something to a full stop? I thought the fin brakes in roller coasters are eddy current brakes, but isn’t there a physics limitation that prevents them from fully stopping the coaster?
- vagrancyand@sh.itjust.worksEnglish30 minutes
Welcome to the world of mostly solid state systems. Turns out when friction is a solved problem there’s no need for cottage industries like brake pad and rotor production.
- 3 hours
Unless they deliberately put in a part designed to wear out in 5 years, there’s really nothing in an electric motor that would.
- FireRetardant@lemmy.worldEnglish2 hours
Bearings can sieze up, starting capacitors can go. A worn bearing can overheat the windings and cause damage.
- 2 hours
Yes, but those are things that can be designed to last decades, at very little cost.
- FireRetardant@lemmy.worldEnglish2 hours
They can’t have perfect quality control for every part that leaves the manufacturer, especially considering the massive temperature fluctuations they might experience, humidity changes, road salt, and the fact its attached to something hitting bumps and potholes at 100+ km/h.
- 1 hour
So… how do manufacturers of hydraulic brakes do this?? Or any other safety- critical part on a car?
- FireRetardant@lemmy.worldEnglish34 minutes
They don’t. Parts like calipers failing and rotors warping is common.
- FireRetardant@lemmy.worldEnglish2 hours
Subscription to the live cloud service that connects your pedal to your braking system
- Skyrmir@lemmy.worldEnglish7 hours
That’s going to be very interesting to see failure rates and modes on the road over time.
- Trilogy3452@lemmy.worldEnglish5 hours
We at least know it could potentially have really low failure rates since airplanes have the same type of systems today, and that’s highly regulated
- kjetil@lemmy.worldEnglish3 hours
I’m more concerned about the failure mode than the failure rates. Mechanical and hydraulic brakes can experience gradual failure, giving the driver a chance to pull over get the car repaired.
EVs usually have a single motor and a single inverter , both of which can fail suddenly. Electronics usually work perfectly fine until they suddenly don’t work at all (blown fuse, bad connection, blown capacitor etc)
How are they gonna build redundancy so that no single component failure means youre freewheeling downhill on the highway
- phutatorius@lemmy.zipEnglish3 hours
Brakes on airplanes are used infrequently (though when they’re used, they’re safety-critical) so the usage pattern is very different than for cars.
- Cocodapuf@lemmy.worldEnglish20 minutes
I mean, airplane brakes probably have about a 3% duty cycle (the percentage of time they’re in use), so they’re generally idle. For city driving, car brakes probably have about a 25% duty cycle.
If those numbers are close to accurate, that means planes are using their brakes about 10x less than cars.
BTW, I didn’t pull those plane numbers directly out of my ass, but they’re definitely a rough estimate. I’m figuring about 5 minutes of breaking time per flight, counting landing and during the taxi to and from the runway. And I’m assuming a 2.5 hour flight, figuring that could be close to an average flight time.
- Skyrmir@lemmy.worldEnglish60 minutes
That’s the real difference to me, maintenance. Planes have a strict schedule of inspection and replacement. Moms minivan last saw an oil change before the kids made it to middle school. There’s going to be some failures.
- psx_crab@lemmy.zipEnglish7 hours
Brembo’s new “Sensify” braking system takes that one step further, eliminating the hydraulic system entirely and relying instead purely on electronic brake-by-wire and electric motors.
I can see it catch on for EV, pretty sure it won’t be used on ICEV considering brake is the only thing that can stop the car
- FireRetardant@lemmy.worldEnglish2 hours
Downshifting used to be a thing people would do to slow down a car significantly.
- psx_crab@lemmy.zipEnglish2 hours
Takes quite a bit of practice to use it in emergency though, but for normal slowing down it’s pretty handy, and manual transmission tend to slow down car a lot when releasing the gas pedal.
- 2 hours
I engine break all the time as my car has paddle shifters. Reduces the time between break jobs
- FireRetardant@lemmy.worldEnglish2 hours
I’m torn cause i drive a stick and its much more difficult for me to swap out a worn out clutch than doing a brake job. I usually leave a lot of distance and just coast in neutral when approaching stops.
- Retail4068@lemmy.worldEnglish4 hours
plus it saves you money on wear parts, because bypassing the hydraulic system means bypassing the pads and rotors too.
I replace my 911 rotors and pads once every 6 years? They cost $450 for the semi track compound.
These things ain’t saving anybody a dime but the manufacturer.
- grue@lemmy.worldEnglish2 hours
I replace my 911 rotors and pads once every 6 years?
Tell me you’re wasting your 911 without telling me you’re wasting your 911.
- Retail4068@lemmy.worldEnglish2 hours
You’re right, I don’t track or hpde it that much anymore. I’ve moved on to actual race car shit. 4 lemons a year. You’re barking up the wrong tree. My current build, spec 3.
- Mpatch@lemmy.worldEnglish58 minutes
That looks far from built. Fact it looks more like your going a bit backwards there bud. Lol
- Mpatch@lemmy.worldEnglish3 hours
That’s just bad anecdotal evidence. A 2001 jetta, a full pad and rotor swap can be done for sub $200, a 2020 silverardo the rears alone will cost about $800, a 2010 gmc Acadia will run about $1100 for all four. And this could be from every year to every 6 years based on how many km are put on a given year.
- Retail4068@lemmy.worldEnglish2 hours
And you really think even at a grand it’ll save you anything? Very few people outside of sports cars are replacing brakes that often. It’s like buying a 70k new EV to “save money” on gas with some copium that you’ll be the 3% to own the car for more than 6 years.
On ice vehicles this is dumb. Hard and expensive to repair for a brake pedal that feels like shit. Absolutely fucks the secondary and third owners looking for a cheap simple car to keep running.
- vagrancyand@sh.itjust.worksEnglish23 minutes
Tell me you live in a flat unpopulate ddesert without telling me you live in a flat unpopulated desert. If you’re the 85% of humanity that lives along a coast you are not getting away with replacing your rotors any less than once every couple of years.
- Mpatch@lemmy.worldEnglish1 hour
Oh I think that this idea is fucking stupid. But to say that you only replace brakes every 5-6 years is even fucking stupider. Hell in a given year I can put on 40-50,000 km ill be doing brakes way sooner than most. Especially if it’s a year where I’m towing trailers amd gear to job sites. Fleet veichles, taxis, ubers, delivery veichles, rentals. Those rack up km quick. Compared to a daily driver that goes 20km to work and back… or a summer roadster.
- unitedwithme@lemmy.todayEnglish2 hours
What?? You don’t replaced your brakes at 5-6 years? If you drive under the US national average of 12k/year it should be around every 50-60k miles, so 5-6 years. Normally you hear the brake wear indicator squealing sound. Do you wait for the grinding noise to start and a funny smell? Yes, most people ARE in fact replacing at about 5 years. More often the cheaper you go as they wear out faster.
3 hoursI’ll take $450 in my pocket every 6 years, thanks. The bigger savior is not having your wheels constantly caked in brake dust.
Brembo’s new “Sensify” braking system takes that one step further, eliminating the hydraulic system entirely and relying instead purely on electronic brake-by-wire and electric motors.
ok but…y tho?
- vagrancyand@sh.itjust.worksEnglish25 minutes
Brake rotors are $500-$1500/set, pads are $50-$200/set, Friction and rust welds are common enough to damage other parts of the knuckle over the expected life time meaning that bill can easily turn into a $2k-$5k repair, totaling the car depending on the age.
Eliminating regular maintenance costs and production costs for a system that works essentially just as well (and can work better in an emergency if you don’t care about saving the associated motors) means cheaper cars, both upfront and over time, with the only downside being luddites afraid that two decades of EV data from a few dozen million cars isn’t enough to prove safety versus hydraulic.
- 3 hours
Fewer wear parts and fluids to change sounds pretty nice, actually.
