Slic3r Prusa Edition Announces Latest Release, Offering Updated Supports and Smooth Variable Layer Height

It was only a few months ago that Prusa, the popular open-source RepRap 3D printer company, introduced its customized Slic3r software for Prusa 3D printers. Now, the Slic3r Prusa Edition just got even better, with founder Josef Průša’s announcement of its latest release, Smooth Variable Layer Height. The new release lets users gradually transition across different layer heights in one object – meaning finer layers can be used on sloped surfaces to get rid of that pesky “staircase effect.” Also, while it may not be quite exciting as the Smooth Variable Layer Height, the Slic3r Prusa Edition has also updated its supports, which as any 3D printer user knows, are very important.

Průša notes that while today marks the official announcement, Prusa’s “hardcore” fans may have already tested out the Smooth Variable Layer Height. The concept behind improving the finish of sloped surfaces by changing around layer heights is not a new one – among a few other references, Průša mentions a research paper, titled “Slicing procedures in layered manufacturing: a review” and co-authored by Pulak Mohan Pandey, Sanjay G. Dhande, and N. Venkata Reddy, which provides a pretty detailed look at algorithms used to change layer height, in order to limit how rough the surface is. While some people may ask themselves why such a feature is necessary, Průša has a solid answer.

“The use case is simple,” Průša explains. “3D printing is always about the quality versus the print time.”

In order to illustrate how the new Smooth Variable Layer Height feature works, a 200% scaled up 3D Hubs Marvin is used as an sample object. It takes nearly two hours to print Marvin with a 0.2 mm layer height, which isn’t terribly long. The issue is that the top of his head gets that staircase effect mentioned earlier. You can fix this by printing Marvin at a 0.1 mm layer height, but then the print time doubles, going up from 1 hour 50 minutes at 0.2 mm to 3 hours 45 minutes. If one were to print Marvin at 0.05 mm, it would take about 8 hours total!

Luckily, with the new Smooth Variable Layer Height feature, you can combine the layer height and total print time, just by selecting your object in the Plater tab and choosing Layer Editing from the top menu. This allows you to essentially “paint” which parts of the object you want to add more detail to; in the case of Marvin, the top of his head. The green parts will automatically default to 0.07 mm, which gradually smooths the selected layer.

According to Průša, this smoothing is not present in any other slicing software for FFF 3D printers, but is extremely important, so the layer height jump won’t be so visible for 3D printed objects. You can even print a different part of your object, in this case, Marvin’s legs, at a different layer height, to speed things up even more. By spending less than three hours tweaking the g-code, Prusa was able to cut the overall print time by 1 hour 25 minutes, with the same result!

Click here to download the pre-configured Slic3r Prusa Edition.

In addition to Smooth Variable Layer Height, Slic3r Prusa Edition also reworked its supports, so they are better, faster, and easier to remove. According to Průša, the main focus here was to speed things up by rewriting the supports to C++, which helped make the supports more stable and ensures that an object’s supports are always completely generated. To reduce the final G-code file size and save time, the supports are now generated on the grid.

Something else new that’s been added to the Slic3r Prusa Edition is a helpful “Slicing Info” box, which appears after the G-code is generated. In the box, you can see the amount of filament used for a print, how much it costs, and some other helpful information as well. While some work on parallelization was done in this latest release, Průša said that will be the major focus for the next one – so stay tuned! Discuss in the Prusa forum at 3DPB.com.