We built it within 0.01 tolerances.

This guy is fucking incredible. "Founder" in bio ass motherfucker. In another thread recently he suggested there is no need for what he refers to as "2d's" (engineering prints) and that everyone should just work off of 3D models. This guy supposedly runs an engineering company and has never set foot on a shop floor, engineered anything, or presumably even turned a screwdriver in his life. Every engineer and machinist on Twitter is shitting on him and he's doing that "they hated him because he told the truth" thing. Then you have the handful of dumbasses one-upping him, who think CAM software can be replaced with ChatGPT.
A case study in why Americans will never return to the Moon.
- Imagine being able to have a computer that runs a 3D model constantly that doesn't get shit all over it within the first couple of hours. The reason you have prints is so you can, you know, print it out!
  
  Naa. That can be done. I use a computer on the shop floor. I do CAD/CAM on the shop floor. Yeah, the computer gets fouled up with oil and shit, but fuck it. If it dies, buy a new one. Operating expense. We also have tablets at each workbench. Nothing is stopping us from having an app for viewing 3D models on there. Some people in that thread were like "oh it wouldn't make sense to buy a CAD seat for every machinist." No, that's not it either. Just pirate that shit. Even if it were free, it would be a stupid idea.
  A print is nice, because it can be marked up. I can pull out a pencil and add notes. I can highlight dimensions on it. I can walk it over to an engineer and POINT at a feature (or even, when proper characteristic maps are made, just reference a feature number in a phone call or an email).
  Prints have a design language to them which allows you to express fully constrained geometric designs on a napkin if you need to. Dimensions, radii, diameters, angles, datums, positions, projections, sections, GD&T. None of this is obvious in a 3D model. You don't know what the driving dimensions are, what can be inferred from other dimensions, if it is a coincidence or a requirement that two features line up, etc.
  There are rules to engineering prints. You never dimension a feature when it can be inferred from other dimensioned features. Dimensions are added until nothing is ambiguous, without constraining any feature more than once. It is formulaic. This is fundamental to how manufacturing processes are developed and how inspection plans are generated. It is the fundamental way of proving the geometry of a part has been fully considered. And then once you have it, you can send it to any shop in the WORLD and they will understand exactly what you want. They will be able to inspect parts and know exactly what to accept / reject.
  I do a lot of one-off shit in the shop, making fixtures and custom inspection gages. A lot of times the programmers will skip making a blueprint for things like this and just send me a STEP file, which is FINE. I can select the geometry I need from the STEP file, turn it into a toolpath, and cut it, but it tells me NOTHING about what tolerances I'm aiming for, if it is better to go over/under size, which dimensions are the most important, or what datums I should be referencing when I fixture the part in the machine.
- The guys in the shop know way more about what they're doing than I do. I feel like I'm doing nothing in solidworks, but shuttling back and forth between the workshop and computer. Apparently insurance liked to have drawings though
- Dumb question, but can't you go from a CAD file direct to gcode in fusion for CNCs?
  
  A Solid Model (CAD) file (while very useful) doesn't contain all the information you need to convey what a good part is. There are an innumerable amount of things you want to convey to the manufacturer what you are looking for, from masking parts of a surface, to how parts need to be packaged, to which of the dimensions are the most important and how you should measure them (GDT etc).
  There are services out there that you just upload a solidpart file and they give you a price. They are highly automated, cheap and quick. The parts are not high quality. Often their standard tool sets cant machine a feature. They communicate that and you have to make other arrangements, either alter your design, or plan on doing some post processing. I was actually supposed to place an order with one today, but had some problems with capability so I am altering the design to accommodate those limitations.
  Its sad, but good machinists are a dying breed.

Begging CEO techbros to understand what tolerances really mean, for the love of god.
- These days it will be something like:
  Add it to the AI cloud
- They think it's just a rating from 0-100 of how much you tolerate minorities. Doesn't need any units, don't worry about it.

0.01 what inches? Cause that isn't that tight, but it might not need be with that large a piece but there's no way the entire spec is +/- .01. Those diameters are probably +/-.005
Oh it's 0.01 units of pulled directly out my ass, got it ok ship it out, we good 👍
- Be rest assured, every part has a drunk uncle slapping it and saying, "Yep! That'll hold."
  
  "When in doubt, ship it out"
- I mean, for most parts of a vehicle, within 1/100 of an inch is plenty close enough. Most of the things that it wouldn't be are more generic off the shelf stuff. Like, chevy doesn't make all of their their transmissions, for instance. Tremec makes the ones for the corvette, and some of their 10 speed ones are made by a shared effort between Ford and Chevy/GM. Than Nissan ops to use these POS jnco transmissions, and there's several others. Same for some engines or at least many of the parts in the engines.
  But all the frame, mounts, body panels, holes, brackets, etc...1/100th inch would be fine.
  
  jnco transmissions
  Their pants were much higher quality
- It’s actually 0.01pm, and yes, we will be hiring quantum physicists and building some very fancy lab equipment to check the individual atoms.

1% tolerance. Each dimension can be 1% smaller or larger. Easy peasy.
- O_o
- Lots of dimensionless-quantity erasure ITT.

HOW CAN YOU KNOW YOU'RE BUILDING IT WITHIN TOLERANCES WITHOUT A QA PROCESS THAT'S LITERALLY WHAT A QA PROCESS IS FOR

0.01 international tolerance units

Your units are wrong! cried the teacher.
Your church weighs six joules — what a feature!
And the people inside
Are four hours wide,
And eight gauss away from the preacher!

Only 1 in 100 parts will call you a slur.

Didn't Elon say something demented about Bazingatruckerinos being built with 10 micrometer tolerance about a year ago? This dickhead is probably just regurgitating that.
- Yes I did Kent
- Ya he pull that out of his ass one day and send a company wide email telling everyone that was the new standard, basically so he could win a Twitter argument. Which is insane becuase it would either make the trucks 100x more expensive or is just physically impossible becuase he didn't specify what temperature he was talking about. Also, if anyone has seen a Cybertruck, it is immediately obvious that they don't bother checking tolerances anyways.
  
  Hmm, it's warm today. Guess my doors are not opening