How to Fit the Positional Sensors to the Frame of Your RepRap 3D Printer

By Kalani Kirk Hausman, Richard Horne

Once the frame is assembled, you need to fit the position sensors on your RepRap 3D printer. Your kit may come with an optical or magnetic position sensor. All such components perform the same function.

  1. If the wires aren’t fitted with connectors, crimp pins onto each wire and insert into the three-way housing.

    You may have two or three connections, usually red for the +5V power, black for the ground connection, and white for the signal. Check the position of the electronics end-stop connectors before fitting into the connector housing.

  2. For our example build, we’re using small microswitches; insert a tie-wrap into the two holes in each switch.

    A position sensor can be a simple wired switch or fitted to a small printed circuit board (PCB), so fitting can be via a tie-wrap or screwed into one of the plastic printed parts.

  3. Place the switch on the smooth vertical rod of the Z axis on the left side of that machine; tighten the tie-wrap and cut the excess off.

    This should be a tight fit, but also allow sliding up and down of the switch to position it at the correct height to ensure the printing nozzle home position is above the build bed. When the Z axis is driven down it will touch the switch and activate the electronics to stop at the set distance.

  4. Fit another switch in exactly the same way for the X carriage on one of the vertical 8mm smooth rods.

  5. Fit another switch in exactly the same way for the Y carriage on one of the horizontal 8mm smooth rods, this time at the very back of the machine.

    When the bed moves back to the home position, it will strike this switch and stop.