(2022-01-05, 12:30)Takeshi Takahashi Wrote: I've examined the cause of collisions several times but I couldn't find which part is wrong.
Does the real model rely on plastic flexibility to absorb strain??
Very often, yes. Although in this case it could also be due to the 0.2 mm size difference between real plates (such as in the crane base and possibly the rails) and their LDraw versions.
You can always apply scaling to a part or assembly if you want visual accuracy, such as for rendering.