PrusaSlicer 1.39.1-alpha

Slic3r Prusa Edition Slic3r Prusa Edition 1.39.1-alpha

Summary:

This is an alpha version, introducing an accurate print time estimator, a recommended object thin wall thickness hint, and a couple of bug fixes.

Breaking change! We have split the RepRap firmware type from the Marlin firmware type, see below.

Accurate print time estimator

The print time estimator of this Slic3r release is based on the work of @daid, who integrated the path planner code from the Marlin firmware ↗ into his original Cura slicer ↗. We at Prusa Research have built on the work of @daid, and we have adjusted the time estimator code to follow the rules of our Marlin derived firmware ↗ to match the print times of our machines as closely as possible.

Because most of the 3D printer firmware types including Marlin ↗ integrate a trapezoidal path planner derived from the Grbl CNC controller ↗, the time estimates should be quite accurate for most of the common 3D printer firmware types as long as Slic3r is catered with the correct speed, acceleration and jerk limits.

The print time estimator derives the speed, acceleration and jerk values from the generated G-code, therefore Slic3r needs to have the speed, acceleration and jerk limits defined in the start G-code to match the firmware. For our Prusa i3 MK2 printer, we added the following G-code snippet into the start G-code of the particular printer profile:

Introduction of a new firmware type: Marlin

Slic3r always treated the RepRap, Sprinter and Marlin firmware types equally. However, due to the accurate print time estimator, starting with this release we had to separate the Marlin firmware from the crowd, as the Marlin firmware defines the M203 G-code ↗ (set maximum feedrate) in mm/sec, while Reprap and Sprinter define the same value in mm/min. If you are running Marlin, please make sure to switch Slic3r to a new "Marlin" firmware flavor to get a correct print time estimate.

Please understand, that the official Slic3r ↗ and the earlier versions of the Slic3r Prusa Edition do not support the new "Marlin" firmware flavor, therefore the "Marlin" firmware flavor will be reverted to the Reprap/Sprinter flavor, if you load the Slic3r PE profiles into the other Slic3r and save them.

Recommended object thin wall thickness hint

Slic3r implements a unique plastic flow model ↗, which guarantees a good dimensional accuracy of the prints. However, due to the complexity of the plastic flow model, it is difficult for a designer to define objects vertical wall thickness to fit an integer number of perimeter lines. The new hint shown at the "Layers and perimeters" parameter page gives the object designer explicit thin wall widths to be filled accurately with 2 and more perimeter lines.

This release contains the following bug fixes:

• Fixed mangling of non-English file names when exporting a preset #696.
• Fixed environment variable settings for G-code post processing scritps on Windows, thanks @fredizzimo #674.
• Fixed "Conditional G-code with <= condition fails in 1.38.5" #683.
• Fixed many STL import issues by disabling questionable normal flipping repair attempts performed by the admesh library #206,#228,#230,#259,#262,#269,#413,#574.