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Shell Parts
bin shell part thumbnail bin
cee shell part thumbnail cee
vee shell part thumbnail vee
corner shell part thumbnail corner
sofa shell part thumbnail sofa
tube shell part thumbnail tube
A prpol bin shell part

This is what is generated from bin(dimensions = [5, 3, 2]);.

Customizing shell parts with OpenSCAD parameters

The shell group has six parts: bin, cee, vee, corner, sofa, and tube. They all use the same set of parameters:

bin( dimensions = [3,3,3], plate_thickness = 2.5, chamfer_depth = 0.75, hole_diameter = 3.2, hole_faces = 20, echo_parameters = true );
dimensions the nominal size as an ordered list of 1 cm units, of the form [i, j, k] where i is the number of units along the X direction, j in the Y direction, and k in the Z direction.
plate_thickness wall thickness in mm (default 2.5).
chamfer_depth edge chamfer in mm (default 0.75).
hole_diameter mounting hole diameter in mm (default 3.2, sized for m3 screws).
hole_faces the number of sides used for the round holes (default 20). Higher values give smoother holes but slower renders.
echo_parameters when true (default), the OpenSCAD console echoes the full parameter list when you preview or render the module.

If you leave a parameter out of the module call, that parameter will just have the default value. For example, these are all valid module calls:

bin(); bin([3,3,3]); bin(dimensions=[2,4,3], plate_thickness=3, chamfer_depth=1);
A prpol cee shell part

A block([6,2,2]);fits perfectly into a cee([2, 5, 2]);.

Using shell parts

Shell parts are shaped to fit perfectly around solid parts of the same nominal size. A 3×3×3 block part is exactly 3 cm by 3 cm by 3 cm — and a 3×3×3 bin, cee, or tube is sized so that block fits neatly inside it.

Because of this, a shell part's outer walls sit one plate_thickness outside the 1 cm grid. Keep that in mind when joining shells to other parts: the hole grids of shells joined together don't always maintain a global 1 cm grid the way solid parts do. Attach shell parts with m3 machine screws and m3 nuts.

A long prpol sofa shell part

Adding a brim during print setup can help ensure proper bed adhesion.

Printing shell parts

Always ensure proper bed adhesion to prevent lifting and warping, especially with long parts. Use a textured build plate with a thin layer of glue stick. Wash off the glue every other print job. If needed, use a brim for extra adhesion.

Wait until the part has cooled completely before removing it from the print bed. Thin shell walls are flexible while warm, and prying a warm part off the bed will leave it permanently warped.