Stories of someone's cracked casting. Should we worry about this?

[Brian-MS90D]

This is somewhat true for concrete, but generally not for steel. Cracks in steel (bridge girders) are typically bad as the crack tips have very high stress concentrations/gradients. The high stress gradients lead to the propagation of the crack through the steel plate(s).

One of the dangers of this is that a crack could start at a (relatively) benign area (e.g. stiffener) but then propagate to primary steel elements leading to a structural failure. This is for welded steel girders.

The example in the photo is somewhat concerning however there is not enough information provided. There is a risk that the cracks propagate so I would start by marking the crack extents and observing. I would be surprised if this was allowed for in the design of the castings however I do not know how they were designed. Drilling out the crack tips is a typical method of arresting crack propagation.

Isn't an aluminum casting something of a cross between steel and concrete?

The casting is not pure steel. There are no inner supports (rebar) inside the aluminum casting. IMO neither of our analogies are perfect. I think it can still be true that cracking may not be failure in this case (although as I stated, I agree consumers would not want to see it).

 

[zoomer0056]

Strange, the cracks are only on the bottom. The post insinuates it is all one piece of metal. The crack does not go up through the connected supporting cross members. If it is all one piece, how is this even possible. I think this is a trolling FUD news media, social media post.

 

[Stirfry]

Isn't an aluminum casting something of a cross between steel and concrete?

No.

IMO neither of our analogies are perfect.

I am not providing an analogy; I am describing, albeit very briefly, how fracture mechanics works. The theory is the same for steel, aluminum, cast aluminum, etc. Fatigue life is different between steel and aluminum, however that is another discussion all together.

... I agree consumers would not want to see it..

Agree with you there 100%.

 

[Stirfry]

Strange, the cracks are only on the bottom. The post insinuates it is all one piece. The crack does not go up through the connected supporting cross members. If it is all one piece, how is this even possible. I think this is a trolling FUD news media, social media post.

It is possible to have surface cracks that do not extend the full depth of the material thickness.

I do think the information provided is very limited and would be hesitant to draw any conclusions, and there is the possibility of FUD/social media as you note.

In any case I did check both of mine to be sure

 

[Bouba]

It is possible to have surface cracks that do not extend the full depth of the material thickness.

I do think the information provided is very limited and would be hesitant to draw any conclusions, and there is the possibility of FUD/social media as you note.

In any case I did check both of mine to be sure

The video showed a flashlight underneath the casting shining through the crack…I am also not a structural engineer…but it’s pretty bad..and there is nothing in the structure to make it look like it is self limiting.
If giga castings can’t be made perfectly at speed and to cost then abandon them until the technology improves…don’t make the loyal customer participate in the experiment

 

[tradosaurus]

The video showed a flashlight underneath the casting shining through the crack…I am also not a structural engineer…but it’s pretty bad..and there is nothing in the structure to make it look like it is self limiting.
If giga castings can’t be made perfectly at speed and to cost then abandon them until the technology improves…don’t make the loyal customer participate in the experiment

Being fairly new to the Tesla forum and to Tesla's in general, after reading multitude of posts it seems as if Tesla uses the customer as Quality Control.

I'm worried that when I order and receive my Tesla that I might have to reject it.

 

[Bouba]

Being fairly new to the Tesla forum and to Tesla's in general, after reading multitude of posts it seems as if Tesla uses the customer as Quality Control.

I'm worried that when I order and receive my Tesla that I might have to reject it.

As you say…you have the right to reject…but inspecting these parts may not be possible.
Anything coming out of Shanghai usually has very good quality control
In fact the boss of Shanghai has been promoted..in order to improve quality in the other giga factories I think..so the future might be good

 

[Pianewman]

Being fairly new to the Tesla forum and to Tesla's in general, after reading multitude of posts it seems as if Tesla uses the customer as Quality Control.

I'm worried that when I order and receive my Tesla that I might have to reject it.

The owner's post of the cracked part isn't included in this thread, but IIRC, they didn't report the crack for several months after receiving the car. Therefore we STILL don't know if this is a manufacturing defect or if it occurred after driving "x" number of miles.

There's nothing about QC issues that is exclusive to Tesla manufacturing. Every manufacturer has issues that occur when introducing a new design or an updated model.

Keep in mind: even with all of the hyper-awareness of this crack, there haven't been any additional reports of giga casting cracks. This example has Tesla's attention, and Tesla has probably implemented additional QC inspections to assure no further instances.

As with any manufacturing process, there are QC checks that occur in production. Clearly this one slipped by. We all hope it's a single instance.

 

[zoomer0056]

If giga castings can’t be made perfectly

There is no evidence in the video that this is even a Tesla.

 

[Bouba]

There is no evidence in the video that this is even a Tesla.

Oh I agree....if this is a genuine video

 

[Bouba]

The owner's post of the cracked part isn't included in this thread, but IIRC, they didn't report the crack for several months after receiving the car. Therefore we STILL don't know if this is a manufacturing defect or if it occurred after driving "x" number of miles.

There's nothing about QC issues that is exclusive to Tesla manufacturing. Every manufacturer has issues that occur when introducing a new design or an updated model.

Keep in mind: even with all of the hyper-awareness of this crack, there haven't been any additional reports of giga casting cracks. This example has Tesla's attention, and Tesla has probably implemented additional QC inspections to assure no further instances.

As with any manufacturing process, there are QC checks that occur in production. Clearly this one slipped by. We all hope it's a single instance.

To be fair, you could own the car for years before you would notice something like that

 

[Stirfry]

I'm worried that when I order and receive my Tesla that I might have to reject it.

I remember feeling pretty similar when I went to pick up ours. I was armed with a checklist and ready to inspect every nook and cranny.

After 5 minutes I tossed the checklist and accepted the car as it was pretty much perfect lol.

I am certainly not denying people have had quality issues however I feel that these forums typically highlight all the negatives.

 

[zoomer0056]

I'm worried

'saurus, no need. Just go with checklist and inspect the car. If it doesn't satisfy, reject. We'll, easier to say this when the heart is not involved.

 

[broke_S]

Not to disappoint, cracks never shrink. They only shrink in sci-fi movies with starships made of imaginary self-healing materials. Cracks always expand, slow or fast, unless stopped by a stress relief feature.

 

[Resist]

I hope Sandy Munro does a video about this crack, since he would know more about it than anyone here.

 

[TomServo]

This story started back in May and nothing since. Wonder why the OP has gone silent?

 

[Brian-MS90D]

Being fairly new to the Tesla forum and to Tesla's in general, after reading multitude of posts it seems as if Tesla uses the customer as Quality Control.

I'm worried that when I order and receive my Tesla that I might have to reject it.

ohhhh, you might want to spend a few hours doing a Google search about all automotive manufacturers recalls, lawsuits (deaths), and fraud schemes over the last 3 to 5 decades. Compared to the others, Tesla is a saint.

 

[Stirfry]

This story started back in May and nothing since. Wonder why the OP has gone silent?

Bought back by Tesla and forced to sign an NDA.

/tinfoil hat off

 

[Pianewman]

This story started back in May and nothing since. Wonder why the OP has gone silent?

Exactly.

 

[zoomer0056]

I hope Sandy Munro does a video about this crack, since he would know more about it than anyone here.

It's a FUD story, Sandy has more important things to work on. Well, maybe in the line of that Myth Busters show he could do a EV FUD Busters show.