burtoogle

In this instance, it looks like the layers that are indented correspond to when the hot bed was active and the layers that are not indented correspond to when the hot bed was inactive. So the layer height (distance from nozzle to last layer) is greater when the bed is on and reduces as the bed/print cool down. Therefore it can't be expansion of the bed/print that is causing this effect, it has to be something else. As you say, the bed could warp. It's not clear what the mechanism is here.

Hi, could you please provide a project file? Do File->Save and attach the .3mf file to this thread. Thanks.

So you're saying that the layer variation is caused by the print bed thickness varying greatly due to the wide bed temperature swing?

Glad you have solved the issue. Even though I suggested that it was the heated bed that was the cause of the problem, I don't really understand the mechanism of failure here. What did the gross over/under shooting of the bed temp actually do?

That means that the model is not "watertight", i.e. the edges of the triangles don't meet up exactly so if you poured water into the model, it would leak out of the gaps. Slicers generally require the model to be manifold/watertight. Sometimes you can have a bad model and it will slice OK but that's just luck.

Hi, there's a couple of issues here, apart from the fact that the model is imported into cura with the wrong orientation, it's also not manifold... I rotated and scaled it to fit but, as you can see, the model did not slice well...

PR created, https://github.com/Ultimaker/CuraEngine/pull/1301

You're right and that is because the model you are slicing is solid and the ironing is failing to detect the topmost bottom layer. I have implemented a workaround that I will submit for possible inclusion in future Cura releases.

I looked at that g-code with a viewer and cannot see the nozzle at bed level on layers around 377 and I don't see those red/green wall lines on the bed either so I am pretty sure that this is simply a Cura graphics issue rather than bad g-code.

I'm guessing it's because you're using Python 3.8.4 and, AFAIK, the Cura source from UM is still expecting Python 3.5.7.

If you run the AppImage from UM, does the mouse selection/interaction work as expected?

Ha! I wonder if it is interference from the AC hotbed causing the hotend temperature sensing to go awry? i.e. when the hotbed heater is on it causes the hotend temperature to change?

Spot the difference!

Please save a project file for a print (File -> Save) and attach the 3mf file to this thread. Then we can see the settings you are using. Thanks.

Oh, right, well try it anyway, you never know!

Hi, I wonder if it is related to the heated bed temperature. Could you please try a PLA print with the bed much cooler, i.e. 30 rather than 70 and see if the spacing of that pattern changes. If I am right, I would expect the problem layers to be further apart compared to the part printed with a bed temp of 70. Thanks.

Thanks for the files, could you please also provide the gcode and 3mf files for the PLA cube, thanks?

Could you please provide the project files for those calibration cubes? Do File->Save and attach the 3mf file(s) to this thread. thanks.

Sorry for the hassle, perhaps I should build Mesa against llvm-9 if that is what people have. I'll see what buster defaults to.

installing llvm-7-dev should be sufficient to give you the missing library

That's interesting, I have both -7 and -9 LLVM libraries.

I print PETG (Real brand filament) on a SV01 and use 240/55 for all layers, you don't need the build plate that hot, surely?

I just did that and this is what I got when it started up normally... libGL: Can't open configuration file /opt/mesa-20.1/etc/drirc: No such file or directory. libGL: Can't open configuration file /home/markb/.drirc: No such file or directory. libGL: Can't open configuration file /opt/mesa-20.1/etc/drirc: No such file or directory. libGL: Can't open configuration file /home/markb/.drirc: No such file or directory. libGL: Can't open configuration file /opt/mesa-20.1/etc/drirc: No such file or directory. libGL: Can't open configuration file /home/markb/.drirc: No such file or directory. libGL: Can't open configuration file /opt/mesa-20.1/etc/drirc: No such file or directory. libGL: Can't open configuration file /home/markb/.drirc: No such file or directory. libGL: Can't open configuration file /opt/mesa-20.1/etc/drirc: No such file or directory. libGL: Can't open configuration file /home/markb/.drirc: No such file or directory. drmOpenDevice: node name is /dev/dri/renderD128 drmOpenDevice: open result is 15, (OK) drmOpenDevice: node name is /dev/dri/renderD129 drmOpenDevice: node name is /dev/dri/renderD130 drmOpenDevice: node name is /dev/dri/renderD131 drmOpenDevice: node name is /dev/dri/renderD132 drmOpenDevice: node name is /dev/dri/renderD133 drmOpenDevice: node name is /dev/dri/renderD134 drmOpenDevice: node name is /dev/dri/renderD135 drmOpenDevice: node name is /dev/dri/renderD136 drmOpenDevice: node name is /dev/dri/renderD137 drmOpenDevice: node name is /dev/dri/renderD138 drmOpenDevice: node name is /dev/dri/renderD139 drmOpenDevice: node name is /dev/dri/renderD140 drmOpenDevice: node name is /dev/dri/renderD141 drmOpenDevice: node name is /dev/dri/renderD142 drmOpenDevice: node name is /dev/dri/renderD143 drmOpenDevice: node name is /dev/dri/renderD128 drmOpenDevice: open result is 15, (OK)

You can simply prefix the command line like this... LIBGL_DEBUG=verbose Cura-mb-master-armhf-20200721.AppImage