OpenSCAD Tutorial

A slicer needs a closed, "manifold" solid: a shape with a clear inside and outside. Most problems come from shapes that only touch.

• Overlap parts you want joined, and extend cutters past the faces they cut (the eps trick from lesson 3).
• Avoid zero-thickness walls and shapes that meet at a single edge or point.
• Put the flat face you want on the print bed at z = 0.

Common mistake: trusting the preview alone. Preview can hide touching faces or a #/% debug modifier left in the code. Always render (F6) and check the console for warnings before you print.

When the model is ready, use Export → Download STL in the playground and open the file in your slicer.

Your task: these two blocks share just one edge, which is not a valid solid. Move the second block back by 1 mm in X and Y so the blocks overlap and join into one part.