rotors

keithaspiro_98037714

the Model 3 is now offically/unofficially using FNC treated rotors. and costly process... great news...keep up the good build...!!!!

eeb9_98059165

Cool. Just read up on that.

Coastal Cruiser.

Link please.

Coastal Cruiser.

I took a few minutes to try and cure my ignorance on this topic. What @keithspiro is referring to is brake rotors (as opposed to the rotor in AC motor).

FNC stands for Ferritic Nitro-Carburizing.

Carburizing, also known as Case Hardening, is a coating applied at high heat that both hardens the brake rotor and inhibits rust. There is a posting in the Tesla Motors Club Model S form from 2013 where the issue of rust accumulating on brake rotors being an issue (https://teslamotorsclub.com/tmc/threads/major-rust-on-rotors-in-a-few-hours.15805/). It appears that carburizing can double the life of the rotor.

It is interesting to note that it is apparently GM that has done the heavy lifting on perfecting the carburizing process being applied to brake rotors (which is probably where the Ferritic Nitro part comes in). It would be very interesting to see where Tesla came up with this process; licensed?, developed in-house?, etc.

motortrend com/news/gm-plans-roll-out-of-rust-resistant-brake-rotors-on-selected-models-140867/
acdelcotechconnect com/pdf/MarApr_2012_TechCONNECT_R1.pdf


My takeaway:
1) Remarkable that Tesla would invest in a process for a part that receives relatively low wear. Model S owners, is that a fair statement? For those of you owners with high mileage, have you ever had to replace your brake rotors due to excessive wear?

2) Since the carburizing process inhibits rust, that is a third source of pollution reduction in Tesla vehicles, the other two being ICE emissions (big) and dust from brush wear on legacy electric motors (small, but it's a contributor). Now there will be less airborne dust from rust scrapings from brake rotors.

3) There actually is a small parallel here to the Tesla AC induction motor rotor in this context. The electric motor rotor is is made from copper, which is a more expensive process to forge than traditional aluminum rotors, and requires very high temperatures as well, given that copper has a higher melt point than aluminum.


Still would like a link to the story that Tesla will be using this process. Google was no help.

/cc

topher_98044200

"Since the carburizing process inhibits rust"

Rust can be a problem in cars with regenerative brakes, as the brakes don't get 'cleaned' (i.e used) as often. Something to inhibit rust makes sense.

Thank you kindly.

greg_6

@topher
"Rust can be a problem in cars with regenerative brakes, as the brakes don't get 'cleaned' (i.e used) as often. Something to inhibit rust makes sense."

Yes and having brake pads that drag on the brake rotor due to rust or other contaminants will surely ruin your EVs range as well cause accelerated brake wear and overheating of said brakes.

So makes a lot of sense to spend a little money up front on preventing a downstream issue.

Not sure whether Tesla is making their own rotors is just buying them in from a tier 1 brake component maker.

As to whether Tesla is licensing the the tech directly from GM or just buying it in is likely that they're buying it in.

gavinfaulkner_98090050

This is why my passengers turn into nodding bobble-heads when braking at low speeds in my Leaf. Not, presumably, because I put no effort into baking smoothly approaching intersections. No matter how many times I ask Nissan service to deal with it, the car still comes back the same. I'm guessing its because there is nothing they can do about it.

I'm glad to hear Tesla are making efforts to avoid this.

gavinfaulkner_98090050

Also, braking smoothly.

Nexxus

My take is that the supplier who makes Tesla's rotors is already doing this and wants Tesla to change over to FNC because its easier on the supplier to not have to manufacture the rotors two different manufacturing methods.

jordanrichard_629778

I have had my car since Mar 2014, presently have 81,000 miles and I have no clue what the problem is about rust. The only time rust is an issue and perhaps this what Tesla is looking to address, is when you first drive the car in the morning after driving in the rain. You get what I call rust lock. A coating and that is all it is, of rust forms on the rotor and your pads get stuck. When you go to move, depending on how long the car has been sitting, there can be a lock bang, when the pads break free. You will also get some grinding noise for the first couple brake applications.

Since I know exactly what is happening and why, I don't see it as an issue. I chalk it up to being a characteristic of the car.

jordanrichard_629778

I meant to say there can be a loud bang.