(2023-05-14, 10:14)emmafrost1 Wrote: 2. Official LEGO sets are designed based on specific guidelines and requirements. These guidelines include considerations for stability, compatibility with existing parts, manufacturing constraints, and other factors. The current standard for connectors with a span of 16LDU is 16LDU, and it is unlikely to be changed to 16.4LDU in an official capacity.If the set were designed on a 16LDU span, it would come with 262 links, not 255, because 262 is the mathematically exact number of links the build needs in all mathematically exact LDraw tools when you use a mathematically exact 16LDU span¹. So, as the real LEGO set comes with 255 real links (and the instructions say to use 255 links), it’s proof the official LEGO set was designed to use links that really span 16.4LDU
So, LEGO knows² the real span and uses it to design sets. It’s weird that we don’t. It’s weird to stick with exact in-System lengths when it’s proven they don’t work and nothing would be lost in the addition (I didn’t even ask about a change).
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¹ More precisely: The chain turns around 2x 3648 gears whose centers are exactly 2000LDU apart. 2000/16 = 125 links. Multiplied by 2 to get both sides of the chain, you get 250 links. That leaves you 255 − 250 = 5 links to make the two half-turns around the gears. Two half turns around the gears is the same as 1 turn around one gear. Not possible with 5 links. You need 12 links for that. And 12 + 250 = 262.
The other way around: You need 12 links to make the half-turns at the ends of the chain. That leaves you 255 − 12 = 243 links to cover the 4000LDU on the sides of the chain. 4000/243 = 16.46LDU. (The difference with 16.4LDU is rounding and the fact that it actually takes a bit less than 12 links to make the turn.)
² True, it has happened that LEGO changed designs between production runs to add or remove a link here and there. So their knowledge is rather fuzzy, but it’s still not 16LDU
