One of the other models that Make Magazine used in their 3D Printer reviews was Cushwa’s Owl from Thingiverse. I thought it would be a good test for the slicer comparison as well, something more sculptural than geometrical. This was printed straight from Thingiverse without any cleaning or modification other than scaling it down 60% to save time. I have two KISSlicer prints because I accidentally ran one scaled at 50%. Since I still had hairspray and kapton on the bed from trying to prevent warping in the Torture prints, the Owls were stuck pretty hard. I broke the Cura print just above the talons trying to get it off, so that isn’t a printing artifact down there.
The Owl has some challenging texture in its feathers. The tips are largely unsupported, which gets complicated in the lower half of the body since the perimeters have a bit of overhang due to the body widening from the talons up to the middle of the chest. An additional challenge is the unsupported underside of the beak which needs support to print properly. It’s another chance to see how the slicers deal with a bad situation. The back of the owl is a smooth, even curve which provides a good contrast to the texture in front, and the top of the head is a shallow dome, which can be challenging.
Between the Slic3rs, 072b seemed to do the best at overhangs, with few loops at the feather tips and under the beak. However the surface of the feathers is cleaner in 097, especially in the upper chest. The upper chest is also very good in Cura, but it suffered a lot in the inward slope toward the talons. Not a lot of dropped loops, but it’s possible that the perimeters aren’t laid out with enough overlap between layers to maintain a consistent alignment. KISSlicer has the smoothest surface on the feathers and maintains it the best in the underside of the body. There are a few misaligned layers however.
KISSlicer also handled the underside of the beak best, but had some odd lines across the face. They are happening at the same spot in both prints, so it isn’t some random wiggle from the printer, unless there is something about those layers that is difficult for the printer to execute properly. Those misaligned layers are very similar to the ones above and below, so there shouldn’t be anything unusual about those spots. Cura is inconsistent there as well, with Slic3r handling it the best.
Slic3r 097 is the clear winner at the back of the owl with no blobbing or misalignment. Slic3r 072b has the blobbing from perimeter ends, and KISSlicer has a visible seam as well, though it was mostly flush to the surface. It also had a few odd perimeters that were shifted in X, recessed on one side and sticking out the other. It looks like layer shift, except the rest of the layers are in the right place. It also happens in the same places for both prints. Cura failed here with a bunch of bad layers. It is possible that there was an issue with the Z axis of the printer because it looks a little like squished layers. If so, it was intermittent enough to not show in the other prints.
Cura looks like it overextruded a little bit at the top of the head, yet still left some gaps, and the tufts are a bit rough. Slic3r 072b has perimeter starts in the middle of the tufts, which 097 hid better. The perimeters are a little uneven in 072b which 097 improves on, but still left some gaps. KISSlicer has the most steady lines and solid fill.
It’s a close call between Slic3r 097 and KISSlicer for the owl, only because of the way KISSlicer handled the back. There is a new version coming out soon however, and I’ll have to see if it shows any improvement in this model.