@Phaedrux said in Delta printer first layer calibration:
I think you may have effector tilt which is causing the probe to have trigger heights that vary with XY position. This is a common side effect of using a probe that has an XY offset from the nozzle, and why using the nozzle tip as the probe is recommended on a delta.
Have a look through these search results: https://forum.duet3d.com/search?term=effector tilt&in=titles
I was thinking the same thing.
No tilt can be observed, but nevertheless it may be there.
However, in a bed.g file, the G30 commands can take the H parameter.
Supposedly, this is to compensate for this:
The H parameter is an optional height correction for that probe point. It allows for the Z probe having a trigger height that varies with XY position. The nominal trigger height of the Z probe (e.g. at bed centre) is declared in the Z parameter of the G31 command in the config.g file. When you probe using G30 and the probe triggers, the firmware will assume that the nozzle is at the nominal trigger height plus the value you have in the H parameter. For example, when doing delta calibration, it can account for the change in trigger height caused by effector tilt, if the vertical offset caused by the tilt has been measured
This option does not work. It miss-behaves badly as noted in my original post.
Either I understand something wrongly, or there is a bug in this functionality, or the problem is different (and thus this parameter cannot help me).
What is the proper procedure to calibrate this H parameter?