Laser Triangulation Makes 3D Printer Pressure Advance Tuning Easier

On its face, 3D printing is pretty simple — it’s basically just something to melt plastic while being accurately positioned in three dimensions. But there are many factors that must be considered to get good quality prints.

One such parameter that had escaped our attention is “pressure advance,” at least until we ran into [Mike Abbott]’s work on automating pressure advance calibration on the fly. He explains that the pressure inside a 3D extruder builds up slowly and releases slowly, resulting in artifacts printed when the printhead slows down or speeds up. By adjusting the speed of filament feed before changing print speed, Pressure Advance aims at reducing these artifacts.

The amount of pressure to advance is usually determined by empirical means, but [Mike]’s system, which he calls Rubedo, can do it automatically. Rubedo uses an extruder-mounted laser and a line generator to perform laser triangulation. Rubedo scans a test with lines printed at different pressure advances, using OpenCV.

The video below gives a lot of detail on Rubedo’s design, some shots of it in action, and a lot of data on how it performs. Kudos to [Mike] Thank you for your thorough analysis, the excellent explanation of the issue and what appears to be an effective solution.

Many thanks [Keith Olson] The tip.