I’ve been happily using my Q1 Pro, but I’ve run into a confusing aspect that I hope can be clarified. The issue revolves around the relationship between print speed and Max Volumetric Speed (MVS) in the default profiles.
For example:
  • The Generic PLA profile has an MVS of 14 mm³/s at a print speed of 150 mm/s.
  • The Rapido PLA (HS) profile has an MVS of 24.5 mm³/s at the same print speed of 150 mm/s.

Assuming the formula for MVS is: MVS = Layer Height * Extrusion Width * Print Speed, the actual print speed will be limited by the MVS in some cases, but the user isn’t informed of this limitation.

For instance, with a 0.6 mm nozzle, 0.24 mm layer height, and 0.62 mm extrusion width:
With MVS = 14 mm³/s, the actual speed is limited to ~94 mm/s (which is below the 150mm/s set speed so the print is limited to 94mm/s).
With MVS = 24.5 mm³/s, the actual speed could reach ~164 mm/s (which is above the set speed of 150 mm/s so the print runs at 150mm/s).

This inconsistency raises multiple questions:
  • Is the MVS calculation in QidiStudio and QidiSlicer profiles based on the formula MVS = Layer Height * Extrusion Width * Print Speed?
  • Why are there both print speed and MVS settings? If MVS limits the print speed, why not have just one setting?
  • Why do some default profiles have the same print speed but different MVS values? For example, why does Generic PLA have an MVS of 14 mm³/s while Rapido PLA (HS) has 24.5 mm³/s, both at 150 mm/s?
  • Why isn’t there a warning when the print speed is limited by the MVS? It would be helpful to know if the preset speed cannot be achieved due to MVS constraints.


I’d greatly appreciate any insights or explanations anyone provide.

Thanks
Al