Building innovative physical gizmos in the real world has a unique set of challenges that makes it difficult to prototype ideas fast and iterate at lightning speed. If you want to have impact and get shit done, designing things from scratch and custom fabrication often takes too long. 3D printing is great, but often unnecessary if one is designing for rapid innovation. You can build innovative things quickly when taking advantage of easily purchased items and hacking things together with brute force and creativity. Finding the right balance of off-the-shelf solutions and custom design is key to providing maximum impact when innovating at high speeds on your projects.