cross-posted from: https://lemmy.crimedad.work/post/542998
“It does suck, because everybody kind of makes fun of the Cybertruck. To the outside person, it’s kind of weird, it’s ugly, whatever. Once you actually get in it, drive it, you realize it’s pretty frickin’ cool,” he says. “It’s kind of been sad, because I’ve been trying to prove to people that it’s a really awesome truck that’s not falling apart, and then mine starts to fall apart, so it’s just… Yeah, it’s kind of unfortunate and sad.”
How the hell is that thing legal to sell??
There’s a reason why Musk is paying to dismantle the government.
There’s no consumer protection agency anymore. I wonder why.
I worked at the Tesla plant in Fremont for a bit and most of every car is held together with adhesive. They claim it’s super strong and once heated, it’s stronger than welding… But, I mean… They are still falling apart and I don’t know if that’s because the adhesive sucks or if it’s because every single day, they had to have someone remind everyone that the glue pattern posted at every station where it’s applied isn’t just a suggestion, it’s an engineering requirement for the structural integrity of the part. People were just slapping the adhesive onto shit in any old way they pleased a lot of the time.
Adhesive bonding can be a good engineering choice, it’s used a lot in aerospace, but like any engineering process, it has to be done right. If the thermal coefficient of expansion of the panels is big enough and the adhesive is immovable, the bonds will break. And as you mention, it’s a really good idea to put the adhesive where it’s supposed to go, otherwise it’s not going to work correctly.
In other words, the things were being designed by underqualified engineers who didn’t understand factors of safety, design for manufacturability, or that precision comes at a cost.
I suspect the real issue is the workers aren’t given enough time on the line to do this correctly so they just churn them out to hit the needed metric knowing it will fail after being delivered to the owner.
(X) to doubt
Adhesives can be incredibly strong.
But never a weld.
MEK welds styrene. Cynocrylate forms a mechanical bond. MEK will be stronger in tension, cyno stronger in shear.
Yes, but stronger than welded 304 stainless?
I don’t even know the name of the adhesive they used. I do know that it was made by 3M and that it’s orange.
Well, OK. So maybe that adhesive is stronger than a weld on that particular plastic. Of course, if you’re talking about adhering a plastic to a metal you cannot weld it so Elmer’s would be “stronger than a weld”. But whatever’s going on it’s not adequate.
E: and actually welding plastic together typically isn’t that strong, a mechanical bond can easily be stronger than melting the plastic to weld it.
Epoxy bonding on body panels is super common on many cars now. And it’s the only way to bond incompatible materials like aluminum and high strength steel.
Even steel body panels can’t be welded to high strength steel because the heat affected zone will be weakened by the weld and will crack just outside the weld.
Adhesives to create a mechanical bond, and the 3M body adhesives include glass microbeads that prevent you from squishing the joint too tightly, which makes the bond more effective.
Now using it in dirty or coated stainless steel clearly isn’t working, and the design of thin strips of shiny steel that will grow and shrink a lot, mostly in one direction on a design that was done by a 7 year old in a hurry to draw a truck is another issue.
Good points.
Why aren’t they using fasteners? Cost or weight?