(2025-09-11, 20:03)Huib Versteeg Wrote: I recently noticed a very subtle issue with the geometry of 30022.
The parts file currently uses the same basic geometry for the top as the much older 3145: a flat top with a total height of 40 * sqrt(3) = 69.282... LDU, forming part of a perfect regular triangle with side lengths of 120 LDU.
- However, 30022 is actually slightly taller at ~72 LDU (and has been since its inception in 1996). The difference in height also affects the four studs on the front which seem to be "in system" with the bottom for 30022, which is not true for 3145.
- The top left and right corner are also chamfered with a 90 degree angle w.r.t. the inclided sides, instead of having sharp corners, as a transition to the slightly higher top.
I came across this when working on some relatively niche geometry in a build, where the difference between 30022 and 3145 actually became meaningful. No hurry whatsoever, but this seemed like something that should be easy and quick to fix for someone who knows what they're doing (which unfortunately is not me in this case).
The chamfered/non-straight top is also different for part 3436 between its first use from 1972-1986 (flat top like 3145), and its re-introductions from 1996 onward (slight 90 degree corner protrusions like 30022). No different parts numbers though, and the difference only rears its head in very niche circumstances. I don't know how such small mold iteration differences are to be handled.
Thanks for the notice, 30022 is also available as a raw mesh, and overlying it onto the LDraw part shows the difference. Needs to be taken up.