18mm Compatible Optical Z-Probe

thingiverse

**Tiny Touch MK3**: A Little More Background on Why I Designed This Will Be Available on My Blog. **Printed Parts:**  - **Body**: Printed on its back, mirror it for the _left_ motor. Use a more malleable filament like ABS is recommended; it's easier to cut threads. - **Flag**: Printed on its back, mirror it for the _left_ motor. - **Nut**: Print it twice. - **Thread**: Print it slow, 0.2mm layer height at most. I print mine with 0.16mm. - **Mount**: Optional. I designed it for this carrier. But any 18mm sensor mount will work. **Non-Printed Parts:**  - Optical endstop ([Aliexpress](https://www.aliexpress.com/item/32436920427.html)) - Tiny linear servo ([Aliexpress](https://www.aliexpress.com/item/32972306205.html)) - Servo extension cables – 3pin each. - 3pin JST-XH connectors – 2.54mm pitch. 1 male, 4 females at the minimum, but really, just get a box for less than $10. - A couple of M3 and tiny screws for smartphone or glasses. Putting this together should be dead simple. Push on the male JST-XH connector into body (into those 3 tiny 1mm holes), then screw optical endstop on top of the body, servo below it, screw it on from the back. Add tape or sticker to the thin part of the flag to make it more flaggy, then slide in it into the thread square hole. Also slide the body into the top of the thread; the thick nubbin on the flag should rest on the servo arm. Solder the servo wires into the male JST. Order doesn’t really matter, just align it when crimping the wires. Voltage (red) to board 5V, Ground(black) to board ground, and signal (white or orange) to board signal for each of them. You’re very likely to cross some wires because of how the endstop works. **Configuration:** 1. `M280 P0 S[angle]`; I use `M280 P0 S160` to deploy and `M280 P0 S30` to stow. 2. `M119`; While doing step 1, confirm the Z endstop status by sending it. It should return **open** when deployed, and **TRIGGERED** when stowed. Please don’t just hit home and hope that things won’t crash into each other. 3. `M851 Z0`; Reset the existing Z-offset to zero. It should already be at zero if you just flash your firmware, but just to be 100% sure. 4. `G28`; Home all, or by clicking on the button. 5. `G1 X110 Y110 Z0 F1000`; Move everything to center bottom 6. `M211 S0`; Disable software endstop, so you can go below Z0 7. Now slowly move the nozzle down until it barely touches the bed (do the paper dance). 8. Look at the LCD, and take note of the Z value. For example it’s **-1.2** 9. `M851 Z-1.2`; Set the Z offset 10. `M211 S1`; Enable software endstop 11. `M500`; Save settings to EEPROM 12. `M501`; Load EEPROM 13. `M503`; Confirm settings You’re done. Remember to add `G29 ; ABL` right after auto home `G28` in the start gcode in your slicer. **In Action:** https://youtu.be/m0B4bG6ZImc Results: ``` Send: M48 S1 Recv: M48 Z-Probe Repeatability Test [...] Recv: Finished! Recv: Mean: 0.030750 Min: 0.028 Max: 0.033 Range: 0.005 Recv: Standard Deviation: 0.001601 ```