Calibration cube prints perfect - except Z height

[LeChuck71]

Hello,

I am just wondering whats going on with my print and looking for comments on my problem.

Printing a 20mm calibration cube gives my perfect results for xy dimension and surface quality. My problem is that the Z height is off by 0.3mm - measuring 10.3mm in height.

I'm use Marlin firmware with auto bed level. Probe is 0.6mm above bed when triggering. Z0 is "exactly" on the bed when heated to my default temperatures of 210°C Nozzle and 85°C Bed.

"Funny" thing is that the cube is printed correctly (in height) when slice by slic3r...??

I am currently at work, so I don't have access to my factory settings.

1. Layer height is 0.3mm; Layerheight 0.25mm

Any tips or comments are greatly appreciated

Cheers
Axel

[CompoundCarl]

Well you can always look at the gcode that is generated to see what Z-values the software moves to. Just Ctrl-F search for "; layer" and you can see the Z-values at each layer.

In general, you can always have an error of one half your layer height. So if your layer height was 0.3mm, then just by how FFF printing works, it's possible to have up to a 0.15mm error. So the remaining 0.15mm could easily be due to nozzle position, or the fact that cooling plastic might contract in the XY directions, and then expand in the Z based on how the plastic cools.

But either way, you can check the gcode to see where exactly it's moving and that will probably help answer some of your questions

[LeChuck71]

Hey thanks, never thought about giving the gcode an inspection

[arhi]

how much error you get on 10mm height, 20mm height and 30mm height... then work from there, if the error is constant it's usually overextrusion, wrong measurement, you forgot to remove raft, wrong measuring tool etc etc .. if they are adding up then steps per mm for you Z axis