Is it a pen? Is it a sword? It’s both! Introducing Riptide from Percy Jackson, this 3D-printed version actually writes, actually extends, and can fit into your pocket in our best approximation of a pen-like form factor. PLA is the material of choice, finding a good PLA that emulates celestial bronze is ideal for this project. This is a relatively simple build, but special attention needs to be paid to the printing settings and tolerances, or else the blades will not mesh together correctly. Welcome to Camp Half-Blood.