Tesla Crash in Indy

[MP3Mike]

Handles are powered by battery. How the heck could they retract after power cut?

Because they are only powered to go out. A spring is what retracts them. So when the power is cut the motor stops pushing them out and the spring pulls them back in. (They don't power retract, which is why they can't cut your fingers off if you leave them in when it retracts, the spring isn't that strong.)

 

[lolder]

The M3 doors have two sources of 12 v, the 12 vdc battery and the DC to DC converter from the HVB. According to Musk they have separate paths to the doors, IIRC.

 

[MP3Mike]

The M3 doors have two sources of 12 v, the 12 vdc battery and the DC to DC converter from the HVB. According to Musk they have separate paths to the doors, IIRC.

OK, but the second an air bag goes off the pyro fuse is blown and the DC to DC converter is disconnected from the HVB. Leaving only on 12v source to the doors, the 12 v battery. (But maybe there is a emergency DC-DC converter to provide 12 v that isn't behind the pyro-fuse/HV safety cut loop. But that would leave a possible path for HV to get out of the HVB so it seems unlikely.)

 

[SOULPEDL]

For Model 3, almost all of my passengers have reached the manually pull up the toggle next to them because the electronic button is just a little a few inches further.

Lol, I remember my 1st day of Model 3 "training" and they warned me of people opening the doors by hand which could potentially break the glass in the door (because it won't drop as usual). Everyone wants to try it, windows still in tact.

I use the outside handle as a form of IQ test. "It's open..."

 

[IanAber]

Because they are only powered to go out. A spring is what retracts them. So when the power is cut the motor stops pushing them out and the spring pulls them back in. (They don't power retract, which is why they can't cut your fingers off if you leave them in when it retracts, the spring isn't that strong.)

This makes no sense. The motor drives the handles out then stops. To bring the handles back in the motor reverses. The handle may well be sprung against the motor to prevent it from providing undue force on trapped objects but it will still require power to reverse the motor to allow the handles to retract.

 

[IanAber]

As far as the back seats are concerned, cars have been fitted with child locks for many years that disable the ability to open the rear doors from inside the car. This does not appear to be a problem for any other car maker so why would it be a problem for Tesla?

 

[BozieBeMe2]

Sure from the interior, but from the exterior you would have to break a window to reach a manual door handle. (i.e. if the passengers are unconscious from the crash.)

The same is true of Any car that is setup to Automatically, lock all doors, when in drive mode and above a set speed

 

[BozieBeMe2]

As far as the back seats are concerned, cars have been fitted with child locks for many years that disable the ability to open the rear doors from inside the car. This does not appear to be a problem for any other car maker so why would it be a problem for Tesla?

A very good question

 

[Paul Wolff]

The Model 3 had mechanical door openers inside, which I didn't know until a neighbor pulled it and got out...

 

[Tam]

...There is no loop to cut that removes the 12v supply...

As Tesla explains on the page below, the rationale to cut the 12V battery supply loop:

1) Disable all SRS components: no need for un-deployed components after the collision to interfere the First Responder trying to access to the car.

2) Disable the High Voltage Contactors: Without the 12V, High Voltage Contactors no longer works which prevents the flow of 400V out of the main pack.

This is a precaution in case the High Voltage Pyro-Fuse fail to automatically disconnect the 400V due to non-SRS triggering events such as very low-speed collision. In that case, cut the 12V loop would disable the 400V.

....Nope, my understanding is that as soon as you lose power the handles should retract unless there is body damage preventing them from doing so.

I've never seen any airbag-deployed Model S with its handles retracted.

Please show me a picture of an airbag-deployed Model S with its handles retracted.

 

[Tam]

...Is it true that you cannot open any Tesla (S/X/3) doors from the outside with a failed 12v system?

I don't know about the Model X but that's not true for Model 3 and S.

If Model S and 3 are unlocked and without 12V (as in an activated-SRS collision with 12V loop cut), you can still mechanically open the doors with its exterior handles.

Model S takes one extra step because if it's unlocked and the handles are still retracted (as in when you park your car and walk away without an automatic lock, let the handles retract first then disconnect your 12V), you have to dig in and manually pull them out which is very easily done.

 

[robdavmil]

It has nothing to do with liability. Any normal person knows the guy is a moron. They are simply gambling that Tesla will not want any bad publicity and simply settle out of court. My guess is they will not go away empty handed...undisclosed amount and Tesla admits no fault. Then the lawyers will probably take the proceeds and buy a new Model S with Ludicrous mode!!

 

[SO16]

Sure from the interior, but from the exterior you would have to break a window to reach a manual door handle. (i.e. if the passengers are unconscious from the crash.)

If the door is damaged in any way, often the glass needs to be broken. No different than a locked door.

 

[MP3Mike]

If Model S and 3 are unlocked and without 12V (as in an activated-SRS collision with 12V loop cut), you can still mechanically open the doors with its exterior handles.

Nope wrong on both counts. There is no "12 v loop". You cut the "first responder loop" to disable the HV system. Look at page two on this: https://www.tesla.com/sites/default/files/downloads/Model_3_Emergency_Response_Sheet_en.pdf

It does not disconnect/disable the 12v battery.

The exterior handles are 100% electronic. There is no mechanical connection to the door latch mechanism.

From the Model 3 emergency responders guide:

OPENING DOORS FROM THE OUTSIDE


To open the Model 3 doors from the outside, press the wide part of a door handle inwards and then pull the door open.

NOTE: If the door handles do not function, open a front door manually by reaching inside the window and using the mechanical release handle. See Opening Front Doors Without Power on page 27.

OPENING FRONT DOORS WITHOUT POWER


To open the Model 3 front doors from the inside without 12 volt power, lift the mechanical release handle located near the window switches.

NOTE: Only the front doors are equipped with a mechanical release handle.

 

[SomeJoe7777]

Because they are only powered to go out. A spring is what retracts them. So when the power is cut the motor stops pushing them out and the spring pulls them back in. (They don't power retract, which is why they can't cut your fingers off if you leave them in when it retracts, the spring isn't that strong.)

The implication here is that the drive motor in the handle is energized and supplying force against the spring to hold the handle in the outward position. While I do not know if this is the case or not, it would seem to be to be a poor design from an engineering standpoint. The motors will quickly wear under this condition (energized with current flowing, but no movement to supply counter-voltage). Do you have a write-up, tech bulletin, or other reference that can support this implication?

 

[Tam]

...The exterior handles are 100% electronic. There is no mechanical connection to the door latch mechanism...

Here's the mechanical gear for Model S door handle:




Once the motor rolls the gear to push the handle out, it cuts the 12V to keep the handle protruding.

To roll the handle back in, you have to use 12V to reverse the roll of the gear to allow the spring to pull the handle back in then shut off the motor.

In summary: Model S exterior handles needs 12V to either push the handles out or pull the handle back in by the injecting reverse polarity 12V to the motor. If there's no 12V, the motor does not move, the gear does not move, and those handles stay where the last position they were in.

 

[whitex]

As far as the back seats are concerned, cars have been fitted with child locks for many years that disable the ability to open the rear doors from inside the car. This does not appear to be a problem for any other car maker so why would it be a problem for Tesla?

Maybe something to do with it being an optional feature most people don't use. I bet if a car would automaticaly enable the child locks whenever airbags go off, that would be a problem. That, and of course all 4 doors having child lock enabled definitely a problem

 

[SomeJoe7777]

Once the motor rolls the gear to push the handle out, it cuts the 12V to keep the handle protruding.

To roll the handle back in, you have to use 12V to reverse the roll of the gear to allow the spring to pull the handle back in then shut off the motor.

This makes a lot more sense.

 

[MP3Mike]

In summary: Model S exterior handles needs 12V to either push the handles out or pull the handle back in by the injecting reverse polarity 12V to the motor. If there's no 12V, the motor does not move, the gear does not move, and those handles stay where the last position they were in.

Yep, it appears that I confused that a little. But the motor doesn't actually pull the handle back in, it pulls the paddle gear back that was pushing the handle out. (So the motor can't exert force on fingers that are between the door and the handle.)

But there is no mechanical connection from the handle to the door latch mechanism. So if there is no 12v power, you can't open the door from the outside. (Even if the handle is still sticking out.)

 

[ICE collector]

I am genuinely curious about the ability to escape the car in such a crash (as well as the X and 3, and even etron since they all have electronic latches). Of course the doors could be crumpled to prevent exit regardless of latch type but electronic latches seem like a terrible idea.

One of those window smashing tools would have helped, but the latch design seems flawed.