Well, compensating for the language differences, what I've gotten out of this is: Replace MODEL { model = z_case/mount2 } with MODEL { model = z_case/Parts/Aero/mount2 } And create the appropriate file structure otherwise, the mod will indeed, not function. Sorry OP, but it's your version of KSP. Either out of date, or there's some difference between our localized versions. It wouldn't work until I did this. â–º One CAN use multiple configs in a single folder. As long as the model data is assigned properly, there's no problem. B9 and several other mods use similar setups with no issues. category = Aero Is the reason these appear in the Aero tab. If you want them somewhere else, then be sure to change the assigned category. The center of selection on the mounts needs to be moved back so it's actually at the mounting bracket, and not the very top of the engine housing. This makes them harder to place than it needs to be. ... That all being said. These models do look quite awesome, and I'd love to see an entire ship set based on the style. EDIT: I made alternate configs for mounts 2 and 3 so they can hold an LLL nuclear engine. !