Prevent positive Z-movement bevore homing

General Discussion
1

Hello all,

i am fairly new to Klipper, so be kind if i missed something.

Basic Information:

Printer Model: Self constructed, with cinematics similar to the Ultimaker
MCU / Printerboard: Bigtreetech SKR V1.3
klippy.log not necessary

My printers bed is moving in z-direction. It is driven by a belt-system, which causes it to drop to the z-max position after each power off.
Before each homing, Klipper moves it a few millimeter in z+, driving it in it’s mechanical limits full force.
How can i prevent this? Either every movement in z+ should be strictly forbidden until the axis is homed, or movement must stop when an z-max endstopp is triggered.
Hardware-wise the z-max endstopp is available…

My current printer config:

[probe] # inductive probe on the printhead
pin: ~P1.25 #Z-min pin
z_offset: 0 #-1.90; to be defined

[stepper_z]
step_pin: P0.22
dir_pin: P2.11
enable_pin: !P0.21
microsteps: 32
rotation_distance: 10
endstop_pin: probe:z_virtual_endstop # P1.24 for Z-max; P1.25 for Z-min
#position_endstop: 294 #for testing
#position_min: -0.1 #for testing
position_max: 294
homing_speed: 20

Thanks in advance and have a good evening
Alex

2

Got it :slight_smile:
Disabeling z_hop in the safe homing part resolves the behaviour.

[safe_z_home]
home_xy_position: 100, 100
speed: 50
z_hop: 15
z_hop_speed: 5

So i solved it with homing_override

[homing_override]
gcode:
    G90
    G28 X
    G28 Y
    G1 X100 Y100
    G28 Z
    G1 Z20
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