I have noticed that Slic3r offers a speed setting called "auto speed" meant to give a constant filament pressure at the extruder, which I believe could eliminate filament grinding issues at higher printing speeds.
According to the tooltip in Slic3r, auto speed is calculated from two parameters:
- Maximum speed
- Maximum volumetric speed
Maximum speed speaks for itself, but how can I calculate the maximum volumetric speed of my print?
There's no fixed maximum volumetric speed that works for everyone, there's simply too much variables to account for. By using @Ian Williams explanation you can convert from volumetric to regular speeds but you still need to test what speed works best for your setup.
Just a few of the other variables affecting how fast material can come out consistently: temperature (nozzle & heat brake), extruder motor power, path friction between extruder and hotend, material compressibility, fluidity and glass transition temperature, ..
There are interesting topics on RepRap forums, like this one: