[UMO+\E3DV6] Extruder calibration lead to underextrusion

[Catlord 17]

Hi,

 

I'm trying to calibrate my UMO+ to make her print XT CF20 filament perfectly.

 

I use a hollow cube (20 mm square, one shell, no roof) to calibrate the extruder.

my nozzle is a .4 xtra nozzle from E3D

 

filament is measured at 2.94mm diameter.

 

With a %flow of 90% I have wall thickness measured at .66mm (with digital caliper)

 

I have to lower it down to 70% to have 0.45mm wall thickness but then I clearly have a problem of underextrusion  😕 see attached picture.

Do you have any idea ? 

 

 

 

Edited August 15, 2019 by Catlord
Adding picture

[johnse 31]

What layer thickness are you printing this with? From what I have read elsewhere, using a single wall to calibrate flow rate is not a good measure.

 

To check for proper calibration, print a calibration cube with infill and measure the resulting cube.

 

AFAIK, to check for proper flow and bonding with a single wall, you want to focus on the finish of the surface and layer bond strength of a spiralized cylinder. 

[Catlord 17]

Cube print (and better the calibration cross ) allow to set up the step/mm.

also the calibration cross allow you to see if there in an horizontal expansion parameter you can play with.

 

I'm taking note about the spiralysed cylinder, do you have any reference about it please ? 

 

[johnse 31]

I saw it on a video...but don’t have a link, sorry.