@dkdkrd posted:I'm befuddled to find no such dimensional definition in the O3R realm.
Should not be befuddled; should quickly realize that the various designers either made it up as they went and/or copied each other.
As noted, standards for scale 2 rail exist; 3 rail isn't.
I mean, we all have experienced the variations; some are rather sturdy in their vertical attitude. Others?...rather floppy, limp, droopy, etc., etc..
Little blue pill....