This 3D Printer Bed Leveling tool (Ender 3) uses a Pulse Induction Metal Detection Sensor and a LED Bar graph to show the relative distance from the Print Head to the hotbed. This is an independent add-on that does not require any code changes to printer firmware or wiring. It is easy to attach to check and tune bed levels.
The sensitivity and stability of the device are illustrated in the video by applying downward or upward finger pressure on the hotbed to see the effect on the LED bar graph.
The calibration button on the top of the unit is used to reset the baseline height and recenter the LED indicator to the center of the bar graph.
Example of use
Marvle 3D PLA PLA
100% infill required for strength purposes
Electronics Build Instructions
- Arduino Nano
- Lm339 Integrated Circuit
- WS2812 LEDs X 10
- 10nF polyester capacitor
- 18nF polyester capacitor
- 150pF ceramic capacitor
- 0.3mm Diameter Enamel Copper Wire (2M length)
- Resistors 2.2k, 47R, 1M, 1K
- Vero Board 21x7 holes
- Hookup Wire
- 6mm SPST Micro Tactile Push Button
- External powerbank
Full build instructions are located here on Instructables
1, Attach the Bed Leveling unit to the print head by pushing onto the stock housing. Connect the USB power to the unit. You should see a power-up sequence on the LEDs.
- Adjust Z axis manually down by turning the Z-Axis drive thread until you just hear the microswitch activate with a click.
- Push the calibrate button (gently so as not to move the carriage down or up). Once calibrated a LED should be somewhere in the center of the bar graph.
- Shift the head across the X and Y axis as in the video to determine the relative height of each part of the bed.
- Print the Test Print with the test print file provided and use the Bed Leveler and test print to quickly validate heights. If the LED on the Bar Graph goes down below the reference then the Bed is lower so needs moving upwards. As you adjust the bed level you will see the LED move up to the correct height.
Initial prototype and testing