RE:
@nico-5
Hey, I feel dumb for not reading this earlier.
I just found out a similar...thing. My printer only exhibits this 'false probing' behaviour when the hotend is hot.
The severity is correlated to the temperature of the hotend:
- at room temp, the issue is not present.
- around 100C the issue is present, but infrequent.
- around 135C the issue is present, and barely manages to probe and clean the nozzle about half the time.
- at max temp, 280C -- the issue is constant, and the z-axis actually migrates up, as the retraction is greater than the distance it can move down between 'false probes'.
RE:
Procedure: I homed the printer while cool and moved the z-axis up to 200mm before heating to temp and starting the homing procedure. I only adjusted the nozzle temp for these tests.
These tests are with no filament loaded.
Room Temp: https://photos.app.goo.gl/ZBjCUD8aYRvfnN228
75C: https://photos.app.goo.gl/4FdjBWrW4DkRpZR59
125C: https://photos.app.goo.gl/1isbJsqDedfX9VEg7
175C: https://photos.app.goo.gl/1evHWwhsCQYiG1946
290C: https://photos.app.goo.gl/Un3KwmYzHKr4pELs5
RE: MK4 Probing for plate in mid-air | Issue homing Z-Axis when starting a print
This solved the problem for me. Again, the screws weren't loose, but tightening them up half a turn did the trick. No more mid air probe points! Thanks!
RE: MK4 Probing for plate in mid-air | Issue homing Z-Axis when starting a print
Hello,
I'm wondering if I'm having a similar issue. Here is what I'm seeing on my mk4.
Occasionally, the printer seems to get confused about the position of the Z axis. This seems to happen especially on taller prints. When this happens, the printer will start probing for the plate very high up. Even if I press and hold the knob, then turn the knob to move the Z axis. It won't move down past the point where it thinks the lowest point is, which could be half the way up the axis. Turning the printer off and on doesn't help.
The only way I've found to fix this when it happens is to turn the printer off and manually push the axis down to the bottom. Using the homing feature doesn't work when the printer gets in this state.
Does this sound like the same issue?
RE: MK4 Probing for plate in mid-air | Issue homing Z-Axis when starting a print
It sounds similar, yeah. It seems like it might be a little different.
After the printer homes the Z incorrectly, the knob won't send the printer past where it thanks the build plate it.
But my issue doesn't happen in one spot on the z-axis. It seems to have an equal change of happening anywhere on the Z. It seems most affected by the hot end target temperature.