SOLVED
@Phaedrux said in Problems with BLTouch bed leveling - part 2:
Your homing files are not correct for using a probe to home Z. They are set as if you have an endstop for Z.
G1 H1 moves are for endstops. To use the probe, you must use G30.
See here for examples: https://docs.duet3d.com/en/User_manual/Machine_configuration/Configuration_cartesian#homing-z
You don't need to use M500 at all. You've set the trigger height directly in config.g. But for that trigger height to be used correctly, you need to use G30 to home the Z axis.
This did the trick. I had to craft a special homeall.g To put the nozzle in the middle of the bed, that was where my "base" Z = 0 was done. Also because the would be off the bed when X and Y homed, I could not leave it there. But it all came together and my map provides a "flat" bed.
It is kind of amazing since I have been fighting "potato chip" bed syndrome on my TronXY that has SIX tramming screws! I am not talking about throwing this printer out the window any more.
G91 ; relative mode
G1 H2 Z5 F200 ; raise head 5mm
G1 H1 X-350 Y-350 F1800 ; move quickly to X or Y endstop and stop there (first pass)
G1 H1 X-350 ; home X axis
G1 H1 Y-350 ; home Y axis
G1 X5 Y5 F6000 ; go back a few mm
G1 H1 X-350 F360 ; move slowly to X axis endstop once more (second pass)
G1 H1 Y-350 ; then move slowly to Y axis endstop
G90 ; back to absolute mode
G1 X175 Y175 F2000 ; put head over the centre of the bed, or wherever you want to probe
G30 ; lower head, stop when probe triggered and set Z to trigger height
Thanks for all the pointers!
Be well,
DLC