Sintron MK8 Extruder Z-Sensor and Cooling Fan bracket

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A combination of two objects, a Z-sensor mount bracket for an 18 mm capacitive or inductive sensor and a 40 mm cooling fan shroud to direct cool air onto the print, is necessary for use with a Sintron Prusa i3 MK8 Extruder. However, these components can easily be modified to fit other printers. The instructions for hooking up the sensor are typically found on the side of the sensor itself or in its data sheet. It's also essential to note that sensors like this come in two flavors: PNP and NPN. For more information, see http://www.instructables.com/id/Enable-Auto-Leveling-for-your-3D-Printer-Marlin-Fi/. Additionally, the controller electronics used will affect how the sensor is set up. For a Ramps 1.4, which my printer has, the sensor circuit needs to be connected directly to 12 VDC, not through the z-axis minimum endstop connector. The second wire pair, containing ground and the wire from the transistor 2N2222, should be hooked up to the z-axis minimum endstop connector's ground and signal input. The second fan, which in my case is also the extruder cooling fan, is controlled via the Fan output on the Ramps 1.4, which is D9. This output uses the G-Code M106/M107 commands in the Marlin or Repetier firmware. If you're using a second extruder heater, you'll need to figure out how to hook it up yourself - potentially using 12VDC relays or high power SCRs to turn on both heaters together with D10 output. One important note is that I recently modified this mount to move the sensor behind the X-carriage and closer to the center of travel for the X-Y plane. This was necessary because when the heat bed homed on the Y-axis, the sensor would hang over open space. To avoid this problem, I had to be extremely careful about the homing order and couldn't do a HOME ALL command twice if the sensor wasn't over the heat bed.