CTC Sensor Holder (12mm) for auto bed leveling

thingiverse

I figured it was time to switch from a fixed Z-min value given at a fixed time, requiring constant attention for plate level loss. Be aware that this won't solve the situation entirely, but it will help greatly: - You can use the sensor to level the buildplate without worrying excessively, as long as it's calibrated correctly; - You can check the leveling of the plate less often, making the printer more productive (maybe once every two months); - If you need to raise or lower the plate, but the plate itself is already leveled, you can trim with the pot present on the sensor itself, leaving only a screw to turn slightly right or left; - You will have to set the Z offset to a value less than zero to avoid plate touch from the sensor and unwanted sensor activation. A trimmed value suggested is between 0.1 to 0.2 using a feeler. Now the most important fact: this is an old makerbot clone with dual extruder, Mightyboard REV E, and SAILFISH version 7.8 (my modifications are included since I have an all-metal hot end, plus other mods for power and cooler). The temperature range needed goes up to 300°C, even if not often used. You can find more details at https://github.com/uoitalia/Sailfish-MightyBoardFirmware. Remember that for auto leveling you will need updated firmware; look here: https://github.com/uoitalia/Sailfish-MightyBoardFirmware/releases/. This is functional even for the ATMEGA 1280 boards! - read carefully the description there! The starting GCODE script can be found in the printer settings, as well as the small electrical written scheme that will make this sensor work properly. For leveling: It becomes really easy and simple when you need to level. Pick the control panel of the printer, raise the Z until the plate touches the hot end. Now pick a feeler and lower the hot ends according to your needs (0.1 - 0.2 - 0.3, 0.2 is recommended). Be careful with Z offset; it should become negative and significant. After trimming the sensor so that it will switch on (there's a led on top), lower and raise Z by 0.1 to check if it works correctly. Now you can begin leveling the plate simply by moving the toolhead around, screwing or unscrewing until the light of the sensor turns on. This time it takes really no time to check if the bed is leveled! EDIT ON MAY 31, 2018: I added a version 2 of the holder, which can be used if you need to tighten the screw or use an inductive sensor type. Remember that with the inductive sensor type, you MUST use the diode and control if the voltage is near zero in the black wire before connecting it to the board.