I’m modeling what will eventually be a small injection molded component. It has two vertical walls that start straight for a centimeter or so and then curve about 90 degrees. The walls are 2.5mm tall and 0.5mm thick, and since my Mini has a 0.5mm nozzle it’s right at the limit of resolution. I knew that going in but wanted to see what was possible.
Amazingly, the curved portion comes out just fine - but the straight portion does not! On one of the walls the straight portion is utterly absent. On the other wall, the nozzle deposits a single drop (no horizontal movement) in two locations where the wall should be, thus building two extremely narrow pillars instead of the wall.
As an experiment, I thickened both walls to 0.75mm. Bingo - the walls appeared just like they were supposed to, other than being 50% too thick.
This has to be Cura’s slicing algorithm, since the Mini will only do what the GCode tells it to do. Hence the reason for putting this in the “Software” forum. I would presume Cura is enforcing a minimum feature width based on the nozzle diameter, except that the curved portion is also 0.5mm and it prints just fine.
Is this basically a “try it and see if it works” sort of thing? Or is there some tribal folklore that says “you can print narrower walls if they’re curved than if they’re straight?”