PrusaSlicer 1.33.3

Slic3r Prusa Edition Slic3r 1.33.3 - Prusa Edition

Summary:

This is the Slic3r 1.33.3 - Prusa Edition release. This is a beta release, introducing two new features: Variable layer height and reworked supports.

When using this release of Slic3r with the Original Prusa i3 MK2 printer, following configuration files shall be used: github.com/prusa3d/Slic3r-settings ↗

Variable layer height

Variable Layer Height

The idea to vary a layer height to improve finish of sloping surfaces is certainly not new.

A paper by Pandey, Reddy and Dhand 2003 ↗ gives an extensive overview of algorithms to vary the layer height to limit the surface roughness, Florens Wasserfall ↗ integrated automatic layer height into his experimental Slic3r in year 2014 as a part of his diploma thesis and Autodesk ↗ has shown their flavor of the variable layer height algorihtm the last year.

We argue though, that while the automatic layer height looks good in scientific papers, it is less useful in practice as implemented in the above mentioned works. We want the layers to become invisible, which requires the layer height to vary smoothly, and we want the layers to be as thick as possible as long as the step artifacts are not disturbing. For an automatic algorithm it is difficult to judge the importance of a feature to be printed in a high detail, therefore one often ends up with the whole object being printed with the thinnest layers allowed, making the automatic layer height useless.

We therefore implemented a slick and quick manual layer height editing tool to give the user a complete control over the details and smoothness of the prints. The user interface is easy to use and the layer simulation gives a realistic real-time feedback of the layer height effects on the appearance of the printed object.

The variable layer height feature offers following settings:

• Minimum / maximum layer height could be configured per printer nozzle, limiting the user adjustments. On Prusa i3 MK2 printer, a reasonable layer height span is from 0.07mm to 0.25mm for the standard 0.4mm diameter nozzle.
• Interactive layer editing could be disabled per printer settings.
• The layer height profile is loaded from / stored into an AMF file.

New supports

The supports were completely rewritten.

• The old supports were very slow, for some objects they did not finish even after couple of days github.com/prusa3d/Slic3r/issues/91. ↗
• The new supports are aligned with a regular grid to guarantee their stability and a speed of calculation. A support tower covers at least a single grid cell, where the grid has the spacing of the base support lines.
• If placed on top of an object, the old supports often fused to the object, being impossible to remove without leaving ugly scars. The new supports control both the top and bottom gaps with a high accuracy, therefore the supports could be removed easily while ensuring a good accuracy of the object overhangs.
• The support interface layers were covered by "interface loops" by default in the old Slic3r. Now the "interface loops" are switchable and disabled by default. With the interface layers enabled but the "interface loops" disabled, the objects overhangs are well defined.
• Spacing between the object and its support in the XY plane could now be configured by a new parameter "supportmaterialxy_spacing". Credit for some bits to @lordofhyphens.
• Maximum support layer height respects the new maximum layer height configured by Printer/Nozzle/maximum layer height settings. This is the same parameter, which sets the cap on the maximum layer height in the variable layer height editor.
• When the support extruder index is set to 0, support is printed with the current material without a tool change. This is useful for multi material print with non-soluble supports, where the tool change is an expensive operation, which should be avoided if possible.
• As before, the supports are printed with layer heights independent from the object layers to speed up the print. To keep a tight control on the vertical gaps between an object and its support, the layer thickness is now being modulated during the print head movement to achieve a variable layer height effect without a movement in the Z axis.

Other changes

This release contains following improvements:

• Calculation of used filament weight & price, thanks to @lordofhyphens github.com/prusa3d/Slic3r/issues/21. ↗ The filament statistics is displayed first after the G-code is exported.
• Write the G-code to a temporary file before renaming to a final name, thanks to @alexrj. This prevents the user to copy an incomplete G-code to the printer.
• Added an experimental "rear" seam option. While Slic3r is good at hiding seams into corners, there are no corners on round objects. The "rear" seam option moves those seams to the rear side of the object. It is left to the user to orient the object with the less important details facing the rear side of the print bed.
• Background processing is now disabled by default as the background processing makes Slic3r unstable, and the default mode is set to expert.
• Added Repetier G-code flavor to support its acceleration settings github.com/prusa3d/Slic3r/issues/106 ↗ , thanks to @lordofhyphens.
• Added logging capability. A logging level is set by an environment variable SLIC3RLOGLEVEL in the range of 0 to 9, where logging is disabled for SLIC3RLOGLEVEL=0 and the most detailed logging information is produced for SLIC3R_LOGLEVEL=9.
• Speed-up due to the parallelization of the slicing step, perimeter generator and fill-ins, thanks to @alexrj.