Magnetic Proximity Sensor Holder

prusaprinters

I wanted to add magnetic proximity sensors to my charge bay and data port doors on my Baddeley MKIII droid so that the internal lights only went on when the doors were opened.I found that most of the super small magnetic reed switches available online were unreliable and very finicky, so I opted to use much larger, but extremely reliable magnetic sensors from Littelfuse that are available through Mouser.To hold the sensor in position, I created this simple bracket that can be glued into place. The slot along its length allows the switch to be easily removed even if you add bulky connectors to the wire ends.The sensors have small ribs near the head that should provide a snug pressure fit when fully pressed into the bracket. The sensor may need to be rotated so that none of the ribs align with the slot and result in a loose fit.Don't forget to modify the doors and embed small magnets to trigger the sensors. I don't recall the exact size magnets I used - they are in the neighborhood of 5mm in diameter and probably 2 or 3mm deep. Whatever you can fit into the door should work - the sensors are quite responsive.Please Note: As depicted in the photo, using this large sensor in the charge bay WILL obscure the three LEDs that are frequently used to display an estimation of your battery charge state. I am not using these LEDs in my build, so it was not a problem for me.