BLTouch Auto Leveling Sensor

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Re: BLTouch Auto Leveling Sensor

Post by ednisley » Thu Feb 15, 2018 2:24 am

sprior wrote:doing Z sensing but not bed level compensation
Got it in one.

The switch mounts on the gantry near the middle and the lever dangles 1 mm (-ish) higher than the nozzle, barely clearing prints-in-progress.

The Z home process goes like this:
  • Move the nozzle off to the right
  • Raise platform to trigger switch
  • Automagically get nozzle offset from M206 in EEPROM
  • Done!
I'm using a somewhat hotrod platform with a PCB heater bonded to the bottom of the glass. Because I never remove the platform (*), the alignment never changes.

The switch mechanically senses the top of the glass, which is the only part of the platform that matters, so it eliminates all the putzing with mounts, bolts, screws, shims, gauges, manual zeroing, dielectric layers, thermal expansion, and suchlike. Measure & set the offset once and It Just Works.

Apparently nobody believes it can be that simple. References on request. [grin]

(*) I print only PETG on hairspray with the platform at 90 C. The part sticks like it was glued until the platform cools below 50 C, it pops loose, and I pick it up. No muss, no fuss, no chisels, no bashing, life is good.

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