Ultimaker printhead with optical table-level auto-calibration sensor and servo

thingiverse

One day, I wanted to make an automatic table calibration on my Ultimaker plywood. Inductive, piezo, tenzo, and other sensors did not suit me because they either took up the workspace or caused problems with the installation of cooling fans for the printed part. This also applies to BL-Touch, and its clones, the quality and reliability of which has recently left much to be desired. As practice has shown, optical limit switches are the best solution in the implementation of precision positioning tools. Based on it, it was decided to make a sensor for automatic calibration of the table level. The principle of operation of this device is similar to the principle of the same BL-Touch. Except that the sensor uses an optical limit switch, not a Hall sensor and a servo drive instead of a retracting solenoid. Thanks to the long probe, the entire device was able to be placed on top of the print head. As a probe used a bicycle spoke. The thread is shortened to 5 mm, the length of the entire probe is 80 mm. Guides for the probe are two Volcano nozzles, the holes of which were drilled up to 2 ... 2.2 mm. You can use outdated nozzles. You can do without nozzles at all. The archive has a printhead housing file with holes without thread - U5_AUTO_LEVEL_E3D_HOLDER_NO_NOZZLE. Probe Offsets: X=20 mm, Y=0 mm, Z=-2 ... -1.5 mm (experimentally selected). P.S. For adequate operation, it is strongly recommended that you solder two capacitors into a wire break directly near the servo. Electrolytic 100 µF - between the positive (red) and negative (brown) wires, ceramic 0.1 µF - between the signal (orange) and negative (brown) wires. This is done to eliminate interference. It is also necessary to power the servo from a separate DC-DC converter, after setting 5 Volt on its output. This will offload the 5 Volt bus on the 3D printer board. https://www.youtube.com/watch?v=dzim4jhBjuY https://www.youtube.com/watch?v=yESJPz21lvs https://www.youtube.com/watch?v=xsbyDk3j1VI