Pictured is my 3D printer shortly after a fire that occurred while I was printing prototypes for my CoxBox. The incident occurred while I was at school, but I was alerted by my internet connected 3D printer controller. Following the fire, I had two hurdles to overcome.
First, I was faced with rebuilding the 3D printer which involved a re-calibration, removing an abrasive dry-chemical fire extinguisher agent, replacing the extruder and melting chamber, replacing the controller board, affixing a smoother power supply, replacing the heated bed, and replacing all bearings and control rods--everything was replaced except the frame. The second hurdle was addressing my parents' concern about safety. I designed a failsafe measure to minimize the possibility of a similar event. I created a smoke-detector interlock and relay system that shuts the power off to the printer when a relay is tripped by the smoke detector. This is intended to prevent electrical fires to which 3D printers are susceptible.
The effort was successful. The printer was rebuilt and operates as good as when it was new, but more importantly, my parents' are confident with the safety measures I put in place.