DrWoo

I have to admit that I'm not a Cura user, but use CEL Robox Automaker, which uses Cura as slicer, so the following is a request without knowledge whether such a feature might already exist in Cura. The common method to avoid Elephant feet in 3d prints is – other than tweaking the (first layer) settings for bed temperature, nozzle height and material flow – to model a chamfer at the bottom with e.g. 0.5 mm height at a 45° angle. The problem with this chamfer is that you sometimes forget to add it before exporting the model as STL depending on the geometry and modeler, it might be problematic to add extrusion profiles can no longer be scaled in length (Z direction), as as chamfer does asymmetrically scale with it I read that Cura does have a setting for initial layer horizontal expansion, but an Elephant foot typically stretches way beyond the first layer, depending on the layer height and number of objects placed on the build plate it easily affect 10 or 15 layers (according to my experience the warping of the bottom layers gets stronger as more objects are placed on the bed, thus as longer it takes to complete the base layers, which happens at increased bed temperature for better adhesion). My suggestion/request would be to have an Elephoot compensation option right in Cura, with a height and degree setting, so the slicer adds e.g. a 0.5 mm/45° chamfer at the bottom on the fly (without altering the STL file on the disk).

I just read about the Cubic subdivision infill feature introduced in Cura 2.4 and instantly thought about having had the same idea some time ago for support structures with a larger footprint: Think of starting with few rectangles at the print bed and then subdivide every X layers as closer it gets to where the support is needed. It involves some sagged or even failed bridging on the first layers of each subdivision, but those bridges will heal themselves using the consecutive layers on top. This enhancement (I tend to call it Cascaded Supports) would save quite some time and filament on voluminous objects requiring supports. To give you a better idea, here’s a conceptual illustration, an X-ray bird's-eye view and a view from underneath (bed’s perspective).

I don't own an Ultimaker, but several CEL Roboxes. The printer is really excellent, easy-to-use, very versatile with interchangeable tool heads (dual material just released, drag knife under development, laser engraver and paste extruder on the horizon) and quite affordable. The custom-built AutoMaker software relies on Cura for slicing, which is why I'm posting my question in this forum: I've spotted not only on mine, also on other people’s Roboxes on very fine prints (20 micron layers) the phenomenon of tiny rims, vertically reoccuring approx. every 5 layers. The precision with which the rims reoccur makes me believe that it is not a mechanically-indicated issue, but an issue caused in software, perhaps something like a numerical rounding error. Has anyone of you folks ever seen these rims on any fine Ultramaker prints? If so, could you post images?