Comment by SV_BubbleTime
2 months ago
Something that took me years of working with custom plastic injection part experience to notice still kind of shocks me…
Legos don’t have draft.
That means nothing to 99% of you, but someone else here must understand what the implications of that are for releasing from molds at a mass scale.
Actually they do have a draft. The bricks are designed so you don't notice it, both by the draft angle being quite small, and the parting line is moved up slightly so by the time you get to the bottom of the brick you're back to the original width.
https://medium.com/@bsather/breaking-down-the-perfect-design...
I was annoyed at this one time so I took two legos and put them under the microscope. I couldn’t see it. Which is just to say how fucking tiny the scales are here.
For production parts we’re looking at drafts around 3 degrees. Which is… not what they have even considering the tuck back in!
3 degrees is the generic "I don't care and don't want to worry about it" draft angle. In many cases 0.5 degrees of draft angle is a non-issue.
3 degrees on a lego brick would be a difference of .3mm over its height. For comparison an amoeba is about .5mm. If you're zoomed out enough that you can see the length, you're not going to be able to discern the angle. The only way you'd see it is to check for the gap between the wall and a precision square.