Printer Model: Creatbot DE
MCU / Printerboard: Atmega 2560 / Bananapi Zero klippy.log
Describe your issue:
I have a Creatbot DE printer which I am converting to a llipper control. And I have a strange problem because it prints in the air.
When homing manually, the Z-axis positions itself correctly over the table.
But when I start the print, after homing, the Z axis moves up and prints in the air. I know it sounds strange, but the axis moves by z_hop_value after the homing is finished. When I changed z_hop_value to 10mm, it was printing 10mm above the table.
I’ve shown everything in the video, note that after homing the Z axis moves 5mm and takes that value as the new zero.
After disabling the z_hop the Z axis does not move up after homing and it prints OK.
Please help as this is not my first clipper printer and only here something like this happens.
Z_offset is set correctly to 0.775mm. I checked it multiple times, as this was also my first thought.
How that would explain the fact that it prints OK when I disable z_hop?
[safe_z_home]
home_xy_position:
# A X, Y coordinate (e.g. 100, 100) where the Z homing should be
# performed. This parameter must be provided.
#speed: 50.0
# Speed at which the toolhead is moved to the safe Z home
# coordinate. The default is 50 mm/s
#z_hop:
# Distance (in mm) to lift the Z axis prior to homing. This is
# applied to any homing command, even if it doesn't home the Z axis.
**# If the Z axis is already homed and the current Z position is less**
**# than z_hop, then this will lift the head to a height of z_hop.** If
# the Z axis is not already homed the head is lifted by z_hop.
# The default is to not implement Z hop.
#z_hop_speed: 15.0
# Speed (in mm/s) at which the Z axis is lifted prior to homing. The
# default is 15 mm/s.
#move_to_previous: False
# When set to True, the X and Y axes are reset to their previous
# positions after Z axis homing. The default is False.
Looks like klipper behaves as described. i would just delete z_hop and be done with it.
just in case, this z-hop has nothing to do with the one you set in your slicer if you e.g. cross perimeters.
To be honest, it seems to me that you don’t know what you are talking about or you don’t understand what the problem is.
#z_hop:
# Distance (in mm) to lift the Z axis prior to homing.
In my case, the Z axis moves AFTER homing and not BEFORE.
Removing z_hop is a ridiculous proposition. I’ve done it currently as a temporary solution, but having bltouch you can’t use the printer without z_hop. Sometimes there may not be enough room for the needle to eject so you won’t be able to home the printer.
Translation: If you home, and your nozzle is below z hob height, klipper will lift your nozzle to z hob height. That may explain why you are printing in air.
For your urgent need to use z-hop because of your BLTouch. I am running the same setup and fixed the deploy issue via homing override to not have to deal with z-hop:
[homing_override]
gcode:
# Z Hop first
#Rel. Positioning
G91
G1 Z5 F1200
# Home X and Y Axis
G28 Y0
G28 X0
# Absolute positioning
G90
G1 X110 Y110 F6000
G28 Z0
# Lift nozzle to 8mm
G1 Z8 F1200
axes: xyz
set_position_z: 0.0
In any case, I understand that you don’t value people spending their time trying to help you. Hence, you are welcome to ignore my gibberish and find someone else to take care of your issue. good luck and bye.
