First this not my best work by far. I am staying in a hotel and have limited resources to be able to build this properly.Some of the new owners of ToMs have been experiencing problems with the extruder motor failing after a short time. I was able to see that the problem is related to glitches on the extruder controller board possibly due to the power supply. As a work around until MBI develops a proper fix, I have added this relay board to the output of the EC board. As a result I have been able to print several objects with out issue.All of the parts are available at Radio Shack. Follow the schematic attached. Be careful of the diode and capacitor polarities. See cautionary notes on the schematic.