Are underside reinforcements relevant?

[Peter Blomberg]

Dear LDraw community,

Part moulds change over time as LEGO improves their designs. This leads to parts having relatively minor differences in their shapes. Sometimes this affects functionality, but often not.

When it comes to underside reinforcements, is it a detail that can be ignored or would you like to see all individual variants for the same part modeled in LDraw? Is it sufficient for you to have one variant in your digital part library or would you like to have all variants?

[Chris Böhnke]

Really hard to say...

Probably this depends on the part itself? Though making such differences makes it a bit pointless.

There are a few builds which have the underside exposed, so having the 'correct' era brick available might be beneficial here.

On another note, some parts (especially the most old and basic ones) have such a confusing array of underside differences, most sites seem to struggle keeping up with just catalogueing them. Also how do you determine which is the correct version for a specific printed brick?

Another issue is probably finding parts. Imagine you have like 3001a.dat, 3001b.dat, etc... Picking the right brick (or at least the same brick everytime) can become quite annoying in some programs.

In terms of 'realism' I would say 'yes', but in terms of practically I tend towards 'no'.

[Gerald Lasser]

Interesting question.

concerning mould differences, e.g. there are different moulds of 3001, where the walls got thinner and to still have cluth-power, some very small filltes have been added. those are not modeled, we kept the 4 LDU thick part. That is fine

Whenever an understud is held in place (reinforced) with a fillet, I would tend to have this modeled. As it is also part of the geometry that prohibits a bar or something else going into this place.
If such a thing is completely invisible, as it is part of an animal consisting of two distinct halfs, I would leave it up to the author, but those can be skipped IMHO, if it is not a transparent part, e.g. like the deer.

An example for a considerable mould change here is the "Duplo Roof Sloped 33  4 x  4 with  9 Bottom Tubes with Awning Overhang". This has two moulds (and design-IDs), which are for the basic Duplo build practically the same. However their underside is very different. 9 versus 5 anti-studs. So this is definately a "yes" to be modeled"

https://library.ldraw.org/tracker/24487
https://library.ldraw.org/tracker/24647

Examples where the reinfocement could be skipped are the "blates" the two plate thick "baseplates" those have usually some diagonal reinforecements 20-30 LDU wide and 1 LDU high, so basically they just make the top of the plate thicker, those are not necessary in my view. Mecabricks models them, but those are not necessary IMHO.

BR
Gerald