• The stock z steps/mm is slightly off on the default z steps per mm from the factory (405 vs 400). The math is easy:
    • 16 (times micro stepping); 200 (full steps/rotation); 8 (thread pitch)
      16 * 200 / 8 = 400 steps/mm (The default is 405).
      Set this new value through Repetier Host. Without this change your parts will grow 0.0125mm for every mm in Z.
  • The first layer gap needs to be exactly what you slicer expects (and be perfectly flat):
    • S3D will use raise the nozzle to the first layer height (so if it is 0.2, it will raise it to 0.2mm from Home) – this is the Zero Gap method (the gap at home should be 0).
    • Cura and others use the Home Z as the first layer (so in this case you level it to 0.2mm gap).
      Perfect extrusion.
  • When everything is working in sync you can get perfect heights (but it is difficult and usually not required to be this precise).