Motion Sensor

Step 5 Preparing the tube

Now take the ink tube and cut a length that will fit between the the two pair of pins. I suggest you cut slightly longer and slowly grind/file it down to the correct length. Make sure you don't force the tube between the pins causing the pins to bend outwards. You also don't want the tube to be too loose when placed between the pins. Try to keep the ends of the tube straight (perpendicular to the length of the tube). Finally, clean up the edges as well as the debris in the tube.