A simple height gauge for setting Prusa PINDA probe height to a consistent, usable height. Bunny scientists selected 0.8 mm as a balance between reliable XYZ calibration and crash avoidance.
Using this gauge to establish PINDA height instead of a poorly characterized zip tie achieves repeatable, consistent height setting. Consistent setting of PINDA height after extruder servicing keeps your live-Z setting at nearly same value before/after service.
Place a piece of paper on print bed. With printer off, manually lower clean nozzle tip to just touch paper. Completely loosen PINDA clamp and let PINDA rest upon this gauge. Tighten PINDA clamp to lock PINDA height. Once done, repeat XYZ calibration. Live-Z thereafter will be near same value as last time you used this gauge.
On my Prusa build plate it ends up -1.000 +/- 0.100
On my 3rd party build plate and it ends up about -1.200 +/- 0.100.
Your Live Z value may differ from mine, but should repeatably end up nearly the same on later occasions.
Nominal thickness of gauge's thin portion should be 0.8 mm. Verify with micrometer or caliper. Lap if needed to make it actually 0.8 mm thick.