In a recent Reddit post, user Tupptupp_XD showcases a slicing algorithm that enables the printing of overhangs without support material.
To do so, Arc Overhang creates the code to print overlapping “concentric arcs” – as seen in the images and YouTube video embedded below – opening up the possibility for large overhangs in almost any shape. The results are a little rough but utterly mesmerizing.
Compatible with nearly any FDM 3D printer running Marlin firmware – and best suited to a 0.4 mm nozzle — Arc Overhang “was implemented using a depth-first approach, where one branch grows as long as possible before splitting,” according to its GitHub page.
When using the algorithm, print quality is greatly improved when printing as cold as possible, with printer fans set to “full blast.” You’ll also need to print slowly so smaller arcs have time to cool and stabilize.
The Arc Overhang algorithm is available on the project’s GitHub repo. Step-by-step instructions, which involve cloning the repo and using Python 3, are also posted to help anyone interested in creating concentric arcs of their own get started.
UPDATE: Nicolai Wachenschwan from Germany improved McCulloch’s code so that you can print existing 3D models, not only synthetic test objects. The code ties into the free PrusaSlicer, and you can access it on Github.
You’ve read that; now read these:
License: The text of "Arc Overhangs Let You 3D Print on Top of ‘Thin Air’" by All3DP is licensed under a Creative Commons Attribution 4.0 International License.