How to make Cura print only 1 (or your choice) of bottom layers instead of same as top layer count

I’ve found a way to hard-set the bottom layer on Cura 21.04 (e.g. to a single layer). This might speed up prints and reduce costs, plus eliminate the need to use brims.

Here’s how to do it, if you wish.

  1. Go to the folder C:\Program Files (x86)\Cura_21.04\Cura\util\ (assuming you used the default install location).
  2. Find the file sliceEngine.py - copy and paste it to make a quick backup.
  3. Open sliceEngine.py in a text editor that properly handles line breaks (e.g. NOT windows notepad).
  4. Go to line 505. It should look like this:
    ‘downSkinCount’: int(profile.calculateSolidLayerCount()) if profile.getProfileSetting(‘solid_bottom’) == ‘True’ else 0,
  5. Change it to this (or change the 1 to however many bottom layers you want to use):
    ‘downSkinCount’: int(1) if profile.getProfileSetting(‘solid_bottom’) == ‘True’ else 0,

Save it and restart Cura. Done.

Note that this will also affect bottom layers of prints that are above the floor of the print, but my prints are wasting a lot of filament on the bottom layers, so this was more important to me for now.