Compact Opto Servo Probe - auto bed leveling

thingiverse

19.07.2019 See also V2 - https://www.thingiverse.com/thing:3756428 25.05.2018 A new version has been added with a longer flag (+1mm) and servo arm featuring an increased radius(+0.24mm) 07.02.2019 Printed in PLA does not withstand enclosure printing at higher temperatures (ABS). The flag is especially affected if it is mounted with the spring. 27.12.2018 - Added back cover Compact opto servo probe. https://youtu.be/cW87qqow3zs Another one has these features: - BL-touch mount and the same rod axis as a result, the same x,y offsets; - The same height as Bl-Touch; - Trigger distance 1.5mm (BL-Touch 2mm); - Stow-deploy distance 5mm as BL-Touch; - Servo angles: stow 90, deploy 10 - as BL-Touch; - Same wiring as BL-Touch; - Way better accuracy than both BL-Touch clones I own (standard deviation around 0.0015 instead of 0.006 up to 0.01) Boom: - Sg90 9g - servomotor, same as this - https://www.aliexpress.com/item/100-NEW-Wholesale-SG90-9G-Micro-Servo-Motor-For-Robot-6CH-RC-Helicopter-Airplane-Controls-for/32442393099.html?gps-id=pcDetailBottomMoreThisSeller&scm=1007.13339.90158.0&scm_id=1007.13339.90158.0&scm-url=1007.13339.90158.0&pvid=cbb2eb4d-690b-45c5-940a-faebf46572a4 - Optical endstop, same as this - https://www.aliexpress.com/item/Free-shipping-Optical-Endstop-Light-Control-Limit-Optical-Switch-for-3D-Printers-RAMPS-1-4/32719651743.html?gps-id=pcDetailBottomMoreOtherSeller&scm=1007.13338.110449.000000000000000&scm_id=1007.13338.110449.000000000000000&scm-url=1007.13338.110449.000000000000000&pvid=979e418f-2237-4b8b-afb4-9be626b929a5 2 - M3x10 screw + M3 nuts 2 - M1.5 x5 selftapping screw (salvaged from old deskjet printer) 1 - spring diameter max 3mm, 10mm lenght (salvaged from old deskjet printer) I did not see any accuracy improvement using spring. 1 - rod max 3mm, min. 21mm lenght (I used a 2.4mm diameter axis salvaged from old deskjet printer) Assembling: Introduce the flag in the frame (see picture) and then the rod. The ensemble flag-rod have to slide easy under gravity action. Pay attention to alignment. Mount servo motor and optical endstop. Wire the board according BL-Touch install instruction and opto servo probe according pictures. Install the firmware, send the command M420 S10 (deploy probe) and install servo arm as in picture for deployed position. I used TH3D unified firmware (TH3D_UFW_U1.R2.7) on ANET 1.0 board. Configuration.h and Configuration_backend.h attached. Stl files can be mirrored to change the position of the probe. In this case set servo angles: 90 for deploy and 10 for stow. The figure in the name of files indicate the diameter of rod