Z Offset is always too far.

brunofporto

Hello,

Even after carefully calibrating the Z-probe and setting the Z-offset at Config.g, or manually sending very aggressive Z off-set values with G31 with the console the nozzle is ALWAYS too high..............

I always need to "baby step" the first layer. If I home Z and send the nozzle to the probe position and to Z=0 it is too far from the bed. What am I doing wrong?

Config-override is clear and only contains PID data....

brunofporto

Just as a teste a did it again:

Cleared the mesh, calibrated the probe, home all and send the nozzle to the probing position and Z=0: there it is the nozzle almost 1mm high... Always the same more or less amount too high.

G30 S-1

Stopped at height -0.551 mm (more or less always the same value...)

Phaedrux

Probe type and configuration? Firmware version?

brunofporto

@phaedrux I think I just found (your) answer to the issue at https://forum.duet3d.com/topic/5097/z-offset-issue-probably-me/8

I'll try it....

brunofporto

@phaedrux said in Z Offset is always too far.:

Probe type and configuration? Firmware version?

Probe type 5 (servo deployed with optical endstop connected to Z_Probe_In)

Firmware Version: 2.0(RTOS) (2018-06-05b3)

Issue is probably related to my home Z or home all macros.......

; homez.g

G91 ; relative positioning
G1 Z5 F4000 S2 ; lift Z relative to current position
G90 ; absolute positioning
G0 S0 X119 Y140 F4000 ; move to center of bed
M98 Pdeployprobe.g ; deploy mechanical Z probe
G91 ; relative positioning
G1 S1 Z-295 F1800 ; move Z down until the switch triggers (first pass)
G1 Z5 F1800 ; go back a few mm
G1 S1 Z-295 F180 ; move Z down until the switch triggers (second pass)
G1 Z10 F1800 S2 ; lift Z relative to current position
G90 ; absolute positioning
M98 Pretractprobe.g ; retract mechanical Z probe

I am not using G30 as you mentioned at the above link

Phaedrux

That could very well be it. You'll also be able to remove the manual M98 calls to deploy and retract the probe as G30 should take care of that automatically.

brunofporto

@phaedrux Just realised that when testing the new homing macros. Will do.

Thank you.