Pressure in advance VS retraction setings



  • Hi,

    After reading abaut, think that the idea behind pressure in advance its similar to retraction settings ( distance and speed) in slicer... I have some doubt:

    • Are the same? Avoid filament leaks when printer are not extruding
    • when printer uses pressure in advance or retraction? Retraction commanded by slicer and presdure in advance printer? But when?
    • if pressure in advance, its tunned, retraction can be speed 0,velocity 0,or near


  • @peirof No they are not the same. If you use pressure advance, you may find that you can reduce retraction.


  • administrators

    Pressure advance deals with compression of the filament in the Bowden tube and elasticity of the motor. Retraction also deals with backlash in the filament feed system, and oozing during travel moves. So when using pressure advance, you can reduce retraction but not eliminate it.



  • @peirof said in Pressure in advance VS retraction setings:

    Are the same? Avoid filament leaks when printer are not extruding

    Pressure advance has an impact also during extrusion and between retraction.

    Below is a graph that shows the extruder steps over time, up means filament is pushed in, down means filament is pulled out. The large dips are retractions, the small dips are the work of the pressure advance (K=1.0) that does mini controlled 'retractions' to regulate the pressure at the nozzle, in this example, printing short segment of a Calicat feet layer.

    Without the slicer's generated retractions (pressure advance only), I presume that the large retractions would be much smaller. The slicer is not aware of the small fluctuations and things that the extrusion is a straight line on the graph.

    1569649215343-img-1699.jpg



  • Polymer melt is weird too. Often non-newtonian and compressible. So the idea of x in, so x out is only true after an indefinate amount of time.


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