See the pictures below. I have a severe under extrusion when the printer starts the outer wall, which is resolved by the time it finishes the outer wall. It starts the layer in the same place every time, so it results in this vertical line, on one side of which is fine (where it finishes the layer) and the other side has bad gaps and the wall is much thinner.
In this picture, the problem is on the outer wall (see red outer line, the print head is moving counter clockwise.
And here is the print showing the issue. Just fine on one side, but terrible on the other, precisely where it starts the layer. Strangely, this only occurs on the layers with infill. The top layers seem fine (despite starting in the same place). I have disabled retraction with no effect.
Is there some setting that I should be tweaking? I've exhausted my own ideas of different tweaks to no avail.
The printer is a Monoprice Maker Select V2. I'm using Ultimaker Cura 4.1.0.
- Material: PLA
- Layer height: 0.24 mm (in the pictures, but replicated with 0.16 mm also)
- Temp: 205 °C, here (but tweaking this hasn't had any effect)
- Retraction: Disabled
This doesn't happen on layer changes. Although it does line up with the Z seam, you can see from the G-code visualization below that the outer wall is the very last thing it does. The issue occurs at the start of the outer wall (still on the same layer) that it has the issue, but by the time it ends the wall (just before switching layers) it is fine.
I've tweaked a few other settings, one by one, and seeing if any have any effect. So far, not really:
- Outer Wall Wipe: 0.2 (default), 0.8, 0.0
- Jerk Control - Wall Jerk max velocity change, 5 mm/s
- Outer Wall before inner (Yes instead of No)
- Wall Line Count (3 instead of 2): This improves it some, but I suspect just by making it a little more difficult to see
What have I done since...
I reset all settings in Cura to a default "Draft" setting and then set layer height to 0.24 mm, and turned off Infill. Then I have tried prints with different settings for "Retract Before Outer Wall" and printing temperature.
Here are those results:
These pics seem to suggest a very clear lag in extrusion. 1 and 2 are different temps. 2 and 3 are different retraction.
195 °C, 0 % Infill, Retract Before Outer Wall: On Note: the retraction setting resulted in a noticeable pause before printing the outer wall. Retraction distance is 6.5 mm, and this is not a Bowden fed device.
There doesn't seem to be anything strange about the G-code, either. Here are the
G0 travels just before the outer wall followed by the wall.
... G0 F7200 X106.319 Y93.413 G0 X106.26 Y93.909 G0 X107.213 Y93.658 G0 X107.8 Y92.542 G0 X107.286 Y90.844 G0 X107.509 Y90.394 ; (outer wall of outside) G1 F1328 X107.985 Y90.707 E116.98713 G1 X108.38 Y91.128 E117.01098 G1 X108.658 Y91.623 E117.03444 G1 X108.813 Y92.18 E117.05833 G1 X108.832 Y92.751 E117.08193 G1 X108.713 Y93.315 E117.10575 G1 X108.463 Y93.837 E117.12966 ; (first curve complete, on to straightaway) G1 X99.631 Y107.716 E117.80936 G1 X98.912 Y108.59 E117.85612 ...
Even more done...
These are retraction off, and 205 °C
So it seems like an acceleration thing. If I can figure out how to get it to slow down in just the right spots or compensate in some way, then perhaps I can make this problem go away with minimal sacrifice in total speed.