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

[Pianewman]

Resist: Are you a structural engineer that specializes in aluminum casting? If not, maybe consider that the area with the crack has a cutout, a large whole, to access another component of the vehicle. I interpret that to mean that the area of the crack is a non-structural part of the casting. That's totally my opinion.

Until a legit engineer posts in this thread, we're all guessing. I agree that ANY CRACK is disturbing, and might indicate an issue, but I don't agree, w/o further information, that "it's a huge safety concern,"

 

[Unclepaul]

Spreading FUD

 

[electricar]

There is no part of the casting that is not structural - OEMs don’t waste material for cost reasons alone. The smart thing would have been to quietly replace the part or give the customer another car and hope that this is a one time problem because if it turns out to be a common problem and requires a recall it will be massively expensive and if the tort bar gets involved there will no choice but to recall the cars.

 

[electricar]

It’s my understanding that the only cars with the front casting are the SR model Ys. Is this correct?

 

[E90alex]

It’s my understanding that the only cars with the front casting are the SR model Ys. Is this correct?

Correct

 

[mspohr]

There is no part of the casting that is not structural - OEMs don’t waste material for cost reasons alone. The smart thing would have been to quietly replace the part or give the customer another car and hope that this is a one time problem because if it turns out to be a common problem and requires a recall it will be massively expensive and if the tort bar gets involved there will no choice but to recall the cars.

All parts have structural as well as other functional (access, etc.) and cosmetic components. Nothing is ever just structural.
This part has filler between the structural beams. We don't know what function these flat filler areas perform. It could be something like improving the flow of material during molding or guarding a particular area to prevent water access.
Until we have input from a knowledgeable engineer, we are all just guessing (and some of us are quick to spread FUD and "cover-up" accusations).

 

[smogne41]

There is no part of the casting that is not structural - OEMs don’t waste material for cost reasons alone. The smart thing would have been to quietly replace the part or give the customer another car and hope that this is a one time problem because if it turns out to be a common problem and requires a recall it will be massively expensive and if the tort bar gets involved there will no choice but to recall the cars.

Would one of these castings even be considered replaceable?

 

[mspohr]

Would one of these castings even be considered replaceable?

Probably not replaceable without disassembling the entire front/rear of the car... so no.
Might be able to be repaired if it is structural.

 

[bfayer62]

There is no part of the casting that is not structural - OEMs don’t waste material for cost reasons alone...

That's not correct, many sections of the Tesla castings are non structural. They use the casting to lower the cost of production and reduce the number of individual parts. many portions of the Tesla castings are there to replace accessory brackets (such as for the washer bottle), and provide alignment points for the assembly line. One multifunctional large part may be more expensive, but if it significantly reduces the number of individual parts and processes, it will save money. That is why Tesla has moved to the mega-casting model.

I have no idea if the location of these cracks is structural or not, I'll leave that for the engineers to determine.

 

[electricar]

You’re right about areas that are there for assembly or service purposes but in other areas I guess it depends what is considered structural - to me accessory brackets are structural. The cracks showing the photos appear to be in areas that may gussets resolving forces in that plane.

 

[Bouba]

At the very least I would want the ends of the cracks drilled...and I would also be investigating the practicalities of welding...possibly cold welding or an epoxy...but mostly I would contacting Tesla...again and again...if it’s real of course

 

[bfayer62]

This is one of the pictures that was posted. It is the area directly under the fender L bracket bolt. It looks like a chunk out of the cast gusset. I wonder if something heavy dropped on that casting prior to the assembly process?

If that is indeed the case, this is probably not a fleet wide design problem. Tesla still needs to get to the bottom of it, if for no other reason that they are going to have to anyway once the law suits start. Much better to do it now and let people know the outcome.

 

[TomServo]

Sadly this is giving Tesla a lot of bad press. Hopefully, Tesla will engage with the owner and share their findings.

 

[mhamilton1992]

Everyone that has a Model Y with gigacasting should be checking it regularly now. No old-school body shop is going to know anything about
this. Tesla will have to set the standards, but don't trust their first response ... We have to see how far into the production this type of cracking propagates.

 

[tradosaurus]

Can someone post a picture or diagram where this would be located on the car? Can't tell anything from a close up picture.

 

[smogne41]

The castings are the blue parts on the car on the right. In this case the one in the front.

 

[tradosaurus]

Thanks. How would one inspect the castings at delivery?

 

[Stirfry]

Thanks. How would one inspect the castings at delivery?

You would have to open frunk, the pull off the black plastic covering surrounding the windshield washer fluid fill tube. The plastic covering snaps on and off.

I just checked both my Ys and there are ok.

 

[Brian-MS90D]

I don't know if this is bad or not. However, bridges, buildings, and more have lots of cracks. They flex, move, carry more weight, and serve a more important purpose. A crack does not mean failure. It may, but it doesn't always mean so.

A crack may be bad on a traditional auto frame with hundreds of bolts and pieces (i.e., what we're used to). A crack on this (new) body casting may be less important.

I agree that from a consumer satisfaction viewpoint, it would be best to not have cracks.

 

[Stirfry]

However, bridges, buildings, and more have lots of cracks.

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.