Layer 1 Perimeter Pressure Advance calibration tool

Pressure advance needs to be set differently on the first layer than other layers because of the "squish". Adapative pressure advance settings currently don't allow this. 

If the wrong settings are used then bed adhesion is extremely poor and can lead to perimeters pulling up and ruining the whole print, and "ripping" of the first layer infill, mainly with PETG.

This can be compensated by using very wide first layer line width and reducing first layer flow, but why not tune correctly?

Important things to do before printing:

• You probably need to use Orcaslicer.

• Orcaslicer has the ability to set First_layer_flow_Ratio.

  • I find this is important for PETG and I get much better results with 0.82 flow ratio on the first layer compared to my other layers at 1.0

• Set your acceleration to a low, weird value, lower than your other print modes.

  • I chose 197mm/s/s. This means that "Adaptive Pressure Advance" will use these settings whenever the acceleration is set to 197, therefore I always use that value for my first layer acceleration. 

• Use the if-statements from the attachments and put them into your custom G-code for object change

• I recommend adding the If statement to your "extrusion role change" Gcode as well.

• You must print by Object, not by layer!

• Try to use settings that you will normally use for your first layers - layer height, line width, temperature, speed

My settings

• Printer: MK4S with MMU

• Filament: PETG (geetech)

• Print temperature: use your normal first layer temperature for all layers

Check infill and perimeters

• 1st layer extrusion line width: This is set in the cad file, you can't change it in the slicer

• Layer height: 0.2mm height is much easier to tune in. The file is 0.2mm thick

Check perimeters only

• 0 bottom shells

• 0.0mm bottom shell thickness

• Choose your own 1st layer extrusion line width in the slicer

Notes: 

• The second layer is just there to hold things together, so you don't have 10 loose pieces of plastic that fly everywhere.

• You can generate your own if statement using the excel sheet, or you can just edit the text

Model is available to edit here: https://cad.onshape.com/documents/a97481f6d1ee5108e36c5aa2/w/9b31f216191fce3887a66faf/e/f9adb78bf3382f78dd2315ac?renderMode=0&uiState=6988cdbaa2c98b76b8a3c146