Summary

This is a derivation inspired by richgains "Printable Interlocking Puzzle #1"
It consists of three pieces and makes a 3x3x3 cube.
It isn't too difficult to solve but is his first design that is both interlocking and fully printable without support.

Print Settings

Rafts:

Doesn't Matter

                                            <p class="detail-setting supports"><strong>Supports: </strong>                     <div><p>Doesn't Matter</p></div></p>                                                                                <p class="detail-setting infill"><strong>Infill: </strong>                     <div><p>Medium</p></div></p>                                                        <br>                        <p class="detail-setting notes"><strong>Notes: </strong>                    </p><div><p>Use medium infill to make sure that you get a nice smooth top layer.</p></div>

Post-Printing

Finally, use a craft knife to remove any extraneous bobbles that might jam the pieces together.

Customizer

The variable "Gap" could break the design a little, if chosen too big.

OpenSCAD Printable Interlocking Puzzle #1