SOLVED Significant overextrusion with Cura 3.0.3

[Shipbrook 19]

Decided to give Cura 3 a try, and discovered that my multipart model wasn't fitting together properly (and didn't look as nice as when sliced by Cura 15.04.6). So I printed some calibration cubes (1cm cube with 1mm walls, open at the top) and this is what I got:

 

 

 

 

The left one was sliced with Cura 15.04.6, using settings I've arrived at over time that give good results with my printer. Center one was sliced with Cura 3.0.3, with my best attempt at matching the settings from the first one. Right one was sliced with Cura 3.0.3 using the standard "Extra Fine" profile, but with the layer height doubled to 0.12mm (and the flow rate reduced in OctoPrint to 75%, since printing it at 100% flow got the nozzle encased in PLA, which dragged the print free of the build plate before it was finished).

 

 

I'm not an expert at reading gcode, but it looks like Cura 3's telling the printer to extrude way more material than Cura 15 is. The material profile I'm using has the right filament diameter (and I verified the actual diameter with a micrometer in several places; it's nicely circular and within ±0.01mm of 2.85mm throughout). What's causing this, and how can I fix it? I'd really like to use some of the nifty new features of Cura 3.

 

 

Gcode for all three, if that'll help to diagnose the issue:

Testcube1.gcode (15.04.6 Custom settings) - https://pastebin.com/CVwMnUdF

Testcube2.gcode (3.0.3 Custom settings) - https://pastebin.com/jeVhShJ8

Testcube3.gcode (3.0.3 Extra Fine-ish) - https://pastebin.com/AuvDdJF2

[tinkergnome 927]

Wait, are you printing UltiGCode via USB / Octoprint? UltiGCode uses volumetric values for the extruder axis...

You can print these files from the sdcard or change the GCode flavor to "Marlin" in the machine settings of Cura. It seems that you have done this too for Cura 15.04.

[Shipbrook 19]

Ahhh - thanks! It's been so long since I set up Cura 15 for OctoPrint that I'd forgotten I switched the gcode flavor.

[viny00 0]

Had the same issue with my Ultimaker 2+. Changing machine settings to "Marlin" worked for me as well.