Loadcell Test Passes, but Z-axis test crashes extruder head into base plate
I have just completed my first build, and was running through the self tests. The loadcell test passes fine, both with using a finger to tap the extruder nozzle, and with using a light tap from a hard object. However, during the Z-Axis Self Test, the Z-motors drive the extruder head hard into the printing plate. The right side is visibly lower than the left, and the Y-Carriage is visibly deformed.
Surprisingly, the self-test does not abort for a long time, holding that position and making a whining noise. Eventually, it fails and says the Loadcell test needs to be repeated. But the Loadcell test passes. It's passed 3-4 times now.
Any help would be appreciated.
RE: Loadcell Test Passes, but Z-axis test crashes extruder head into base plate
Can you slide your bed all the way to the back of the printer and take a couple photos from different angles?
If the Y-carriage is visibly deformed, it makes me think something isn't installed properly. Some things to look for:
- Are all bearing clips properly assembled with the rubber and plastic bearing pads?
- Are the bearings fully seated into the Y-carriage pockets?
- Are the Y-rod-holders in the correct orientation?
- Are the expansion joints in the correct orientation?
Some photos of those areas as well may help diagnose the issue.
RE: Loadcell Test Passes, but Z-axis test crashes extruder head into base plate
Podobný problém, test zátěžové buňky mi prošel až na 30-40 pokus a po té přišlo tvrdé zatlačí hlavu extrudéru do tiskové desky v pravém zadním rohu v desce zůstala vytlačená díra. Nakonec to selže a říká, že test Loadcell je třeba opakovat.
RE: Loadcell Test Passes, but Z-axis test crashes extruder head into base plate
I spent a while with Help Chat, and we eventually narrowed it down to a suspected issue with the LoveBoard. On my machine, the filament sensor also does not work, but the specific issue with the Auto Home / Z-Homing was that the loadcell reading (Info > Sensors > Loadcell) didn't change when the nozzle made contact with the build plate, but did change when tapped manually.
I hope to debug this a bit more in depth while I wait for replacement parts to arrive, so does anyone know how the loadcell is supposed to behave? I observe a momentary change when I tap it, but sustained pressure does not produce a sustained change. Is this how the loadcell is meant to function?
If the Y-carriage is visibly deformed, it makes me think something isn't installed properly. Some things to look for:
The Y-Carriage is only visibly deformed during Z-homing when the nozzle is pressed down against the build plate. When not loaded, it appears normally flat, and moves as expected. I have also double-checked the assembly of the Z-axis components, and everything appears correct. Additionally, manual motion in all axes feels smooth.
I believe the fault is somewhere in the loadcell circuit. Under normal operation, the loadcell signal tells the Z homing that it has found the build surface and that it should stop lowering the Z axis, but this signal does not appear to be received. Since my filament sensor is also broken, it makes sense that the LoveBoard is the culprit. The other possibility I've come up with is that I somehow pinched or broke the filament sensor and loadcell wires before the connection to the Loveboard. The other Loveboard functions seem fine (hotend temp control and fans).