On its face, 3D printing is pretty simple — it’s basically just something to melt plastic while being accurately positioned in three dimensions. The devil, however, is in the detail. There are a number of factors and parameters that can affect the quality of the print.
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. His explanation is that pressure builds up in 3D printers and then releases, which causes artifacts to appear when the head of the printer slows 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 through empirical methods. [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] I appreciate the thorough analysis and great explanations of the problem. It looks like a very workable solution.
Thank you [Keith Olson] For the tip.
