ABS is stronger than PLA. Nylon is stronger than ABS. Fiber-reinforced nylon is stronger than nylon. Chocolate is superior to all of these.
I made this printer as a final project for 4.314 (a ACT class that covered the history and societal impact of chocolate). I had the fortune of being able to start out with an (albiet broken) Lulzbot A101 printer; all it needed were a few repairs and a better extruder.
Chocolate is a strange material to work with. It can’t be exposed to moisture, can’t be kept above 40C, and can’t be pumped through tubes (on account of its viscosity). All of these strange constraints led to a strange extruder design that used a heated variant of a syringe pump.
An aluminum sleeve holds a standard (removable) syringe of chocolate while a surrounding coil of thin gauge wire and a thermistor maintain the correct temperature. Aluminum, being a great conductor of heat, keeps the chocolate evenly heated; the syringe, being fully removable, makes cleanup less terrible to deal with.
Like any 3D printer, the settings for extrusion proved to be the biggest pain. Initial attempts resulted in weird amorphous blobs, but future iterations started to turn out well!
I thought my most interesting print was an attempt at gyroid infill - it turned out surprisingly well!
All in all, I probably increased my blood sugar by a few hundred percentage points over the course of this project.