Here's an inside corner trick for FDM printers. Model a small cylindrical 'bite' out of the corner, similar to overshooting the corners a bit in a plate with an end mill so that the pointy corner of what fits the hole will just touch the outer curve of the rounded overshoot. What the goal is with FDM printing is to have the plastic squish out that would normally result in a slightly rounded corner fill in the rounded bit so the corner ends up pretty sharp. It does make the extruder do a wee little dance around the corners but that's more convenient that having to attempt to file out corners. PLA is a hard plastic to file or sand.
Similar principle to the Bell Centennial font that's been used to print telephone books since 1937. All the sharp inside corners have little cut outs called ink traps so when the ink bleeds it forms a sharp corner instead of bleeding a sharp corner to a round one. It's where I got the idea for 3D printing design. For an item that needed a thin slot to snap onto a piece of thick sheet metal, I made small ovals perpendicular to the ends, ensuring that the sides of the metal tab would butt against the sides of the ovals. I cut that part off the model to print a test part, it snapped onto the tab perfectly so I printed the complete part. _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
