When I merge two solid groups, solid tools yield error

Hi, I’m 13 and I’m working on a school project, and I’m learning how to use the solid tools to make a 3d printable airplane model. I’m trying to merge the wings with the fuselage. I made sure that both the wings and the fuselage shapes are solid groups. When I combined them and used the union tool to try and make a unified solid group (with wings and fuselage as one), Sketchup gave me this error: “One or more of the selected objects is either not a solid or is locked. The non-solid/locked objects will be de-selected before this operation is performed.” I then tried to use a solid inspector extension, but that didn’t identify any problems. I also got rid of all extra geometry. Any guidance appreciated. I just want to join wings to fuselage… Here’s my file: AutoSave_printable airpalne model.skp (173.9 KB)

You should

  • correct some face orientations
  • scale up before you use the solid tools (some faces are to small for SketchUp to create them)
  • cleanup this part: