My BLtouch died and I didn't feel like spending 45.00 for another one. I started searching Thingiverse and found Compact Opto Servo Probe by atsnailpace and really liked his design. The optical end-stop that I had was different than his so I decided to do a remix around his design. Since I was designing my own I decided to go with a smaller servo and a sewing needle for the actuator pin. The probe test pdf shows the results of 100 probe test and is a screen print from octoprint. The endstop that I had was from amazon: https://www.amazon.com/gp/product/B07MFT8NWJ/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1 The servo was from Micro Center: https://www.microcenter.com/product/508336/small-plastic-analog-servo Post processing is a little bit of hole clean up. Used a #64 drill bit to ream the hole for the pin guide and a #63 for the pin holder-flag. to get the pin holder-flag to trigger the end-stop I used aluminum tape for sealing duct-work. As designed it takes about .5 to 1mm to trigger. it actually looks like nothing moves. I am using Klipper firmware for my printer so if you need help getting it going with klipper I should be able to help. I am not extremely familiar with marlin but will help if I can. As always if you have any questions please ask, If you make it please post it, I would love to see it. Kevin