UM3E Auto Levelling - Too close to Glass

[adshale_de 0]

Hi,

 

I've been trying to get the auto levelling working consistently on the Ultimaker 3 Extended at my office, but every time I use it on the printer, it moves the print head too close to the surface of the glass. The first layer is "smeared" onto the glass, with it either being paper-thin in places, or so close that nothing extrudes. I have managed to overcome this issue by manually levelling, and I can get accurate prints every time this way. Has anyone had any similar issues, and if so, how have you managed to overcome this?

[DF-Werkzeugservice 9]

Hi,

I haven't had any issues with the Z distance after active levelling. So beofore you try experimenting I'd recommend to make sure that the active levelling process is working really fine (original UM printcores, both of them need to be really really clean, I usually use a brass brush, clean glass plate without any residues of old prints or glue etc...).

 

If this doesn't solve your problem, you could use the little trick I used when experimenting with different build platform adhesion sheets.

As the adhesion sheets like e.g. BuildTak or also painter's tape have a kind of soft surface, the auto levelling of the ultimaker doesn't work due to the used capacity measuring concept.

 

So I did active levelling just with the glass plate to get the relative surface shape of the print bed. Afterwards I put manually a positive or negativeZ - offset into the slicer, depending on the thickness of the platform addition. Then I carfeully monitored the first layer of my prints and fine tuned that value.

As you don't use any adhesion sheets, you can set the Z- offset to 0 and increase it until your first layer looks fine (I usually use 0.05 increments).

 

I use mostly Simplify3D as a Slicer, there you can adjust the Z - offset in the section "gcode". If you use Cura, you first have to install the plugin "Start at Z-Heigt".

 

I hope this helps