Faraday Forge

Extuding into induction coil
Warping due to repeated press fitting

The COVID 19 pandemic has exposed our fragile global supply chains

Specialization across countries has increased logistical overhead and removes any nation's individual agency.

Rapid, scalable 3D printing can be the answer to creating more robust supply chains, and make hardware development more continuous and iterative like software When there was a PPE shortage, 3D printed face shields and respirators were able to get to market faster than traditional factories had ramped up production. To give a computing analogy, if traditional manufacturing is the ASIC, rapid metal 3D printing is like an FPGA.

My goal was to get as far as I could into building a prototype for a metal 3D printer nozzle that utilizes induction to heat the material in 36 hours.

Why induction?

Traditional 3D printers are rate limited by their ability to head up material. Induction can heat up metals faster because part to part contact is not needed for heat transfer.

Binder Jet metal 3D printing systems, like Desktop Metal's printers or Stratysis metal printers, have sped up 3D printing by orders of magnitude, but there are downsides.

Binder jet printers "print" fast, but don't print in 100% metal. After printing, the parts need to be put in a debinding solution which takes around 3 hours to remove the binding material. After Debinding, the parts need to be placed in a furnace for 12-72 hours. The part also shrinks by around 40%, so complex software is needed to predict shrinkage. At larger sizes(grape fruit sized and larger), it becomes really hard to predict shrinkage, because it isn't uniform, making binder jet only suitable for smaller parts.

How I built it

Fusion 360, C++ for Teensy 4.0

Challenges I ran into

I didn't have any screws or threaded inserts. In order to assemble the parts, I had to press fit(expand the part with a heat gun, then press in the components) everything. Press fitting worked really well for larger parts like gears, but after repeatedly press fitting parts, the frames became warped.

I will redesign this to use threaded inserts and proper fastening hardware next time