this post was submitted on 26 Aug 2023
43 points (90.6% liked)

Mechanical Engineering

210 readers
5 users here now

Welcome to the Mechanical Engineering Community!

Rules:

1.) Be constructive and respectful.

2.) No advertising/self-promotion.

3.) No low-effort posts.

4.) No "design this for me" posts.

5.) Images must be relevant to Mechanical Engineering or the posted topic.

6.) We're not doing your homework for you.

founded 1 year ago
MODERATORS
 

cross-posted from: https://kbin.social/m/[email protected]/t/384191

Tesla is facing issues with the bare metal construction of the Cybertruck, which Elon Musk warned was as tricky to do as making Lego bricks

you are viewing a single comment's thread
view the rest of the comments
[–] [email protected] 9 points 1 year ago (1 children)

I'll use inches since I'm American.

+/- .005 inch is a common tolerance when cutting metal with mills and lathes. Also for milling circuit boards as you mentioned. You can get +/- .001 inch if you really have to, but you'll pay for it.

EDM and precision grinding can get you +/- .0005 on small metal parts.

Bending operations in sheet metal are more like .010 or .015 per bend. So if you have 3 bends between screw holes A and B then their relative positions might vary by +/- .045 inches.

With big parts you tend to need larger tolerances, though the parts also flex significantly. You can use the flex to your advantage by designing clever alignment features that make the part deform to fit. Plastic car body panels do this.

I hope Elon is just using a bit of hyperbole to try to motivate his engineers. If he is being sincere then he's delusional.

[–] ziggurism 2 points 1 year ago (1 children)

How much bigger is .001 inch than 10 micrometers

[–] demonhockey 3 points 1 year ago (1 children)
[–] [email protected] 4 points 1 year ago