Comment by double0jimb0

Expert here.

When very precision molds are made, what Noctua talks about in "multiple tuning iterations are required until the geometry, cooling, gating, and moulding parameters are perfectly stabilised" is the standard process for this type of stuff. (Gears, bottle caps, or any molds than make 8, 16, 32, 64, or 128x of the same part in one shot, require that you start with "steel safe" geometry, meaning you mold the first test parts, measure them, and then modify the mold (by cutting material AWAY, it's very hard, usually bad idea, to add steel back to a mold)).

You can do your best to determine what geometry is "steel safe", and all of this is baked upon having very good engineering understanding of what material you are molding (and using very expensive software like MoldFlow to simulate this).

Legos are made from ABS, there are decades of research and data on how ABS behaves in mold, it's relatively safe to use results from Moldflow and be pretty confident in it. Noctua is using LCP. LCP is very niche, and it sounds like they themselves are doing the research on moldability/warp/process effects. And while also being a company that produces things on timelines, the friction/side effect is that sometimes best guesses will fail and they have to start over with new molds (that's a 2 month hit usually) and months of testing. That is what they were trying so say.

I design glass-filled nylon and polycarbonate parts/assemblies with tolerances 1-5x higher than theirs. The 6-month delay they described is something I've lived through many times when we had to "cut new molds" because we couldn't salvage the first mold. (Advanced molds like these are $50k - $200k+). As a company/designer gets more experience with new materials and colorants (like their stuff with LCP), they will probably be able to hit end-goals on first try more often as they collect learnings from their failures.