[Help] blender to 3ds: some objects are turned into small pieces

i’m newbier, only try using blender to create paper craft model
but when i extract blender to 3ds file, some objects seems like being splitted into many part, i don’t know how to fix it :expressionless:
here is when i open 3ds file in Google Sketch Up
and in Pepakura:

In blender, try to move around vertices that fall apart later. If mesh lines follow, well, idk, but if not - you need to join them - better done in wireframe mode, Ctrl+mouse drag around, Alt+m to join.
When moving vertex, do not release mouse button, then hit esc. So you’ll see if it’s ok and shape will stay intact.

Also check if your normals are ok - in edit mode select all vertices, hit Ctrl-n.

idk why the hell it happen :frowning:

Edit each part: select all, Ctrl-N = recalculate normals
In object mode for each part : Ctrl-A Location Rotation

Result :