Magic Numbers

A small calibration test for tolerances that dmarting@ showed me. I wanted to get this done before switching back from 0.25mm to 0.4mm nozzle. This fiddler-like thing has decreasing distance between the cylinders and the frame. The cylinders are supposed to be able to rotate, the smaller distance that can rotate, the better your tolerance. This MakersMuse video explains it nicely, and of course there are now multiple versions floating around. I'm using this particular one because it's fairly small - takes less that 4 hours to print with 0.25mm nozzle/0.1mm layer height. Thinner layer height is not going to make much of a difference, since it's the sideways tolerance that matters. 

With a 0.4mm nozzle, it takes almost exactly an hour to print. Surprisingly, the smallest cylinder show roughly the same lack of actual printing for this and the small nozzle. I'm not sure which parameter to tweak to fix that.

Another interesting tweak: Reducing noise by putting the printer on a slab of concrete (!) standing on foam. Even in stealth mode, my printer is still loud enough to be noticeable on video calls. Curiously, there's a lot of fan noise right at the start, then it quiets down. I should see what's up with the fan.

Watching a bit of Tomb of 3D Printed Horrors (which is more about printing miniatures than about badly failed prints), I bought a few of their models, dialed in a 0.08mm layer height together with the 0.95 extrusion multiplier, and printed the top of the mace skeleton from the Fat Dragon Games Skeleton Set 1. For testing purposes, I cut it at 22mm height and added a raft. The print was beautiful:

At 0.04mm, it's got amazing detail. Remember, these shots are taking with my 1:1 macro lens at full macro, the part itself is 14mm high.  Even at 0.08mm, the layers in the ribs are not visible to the naked eye. Here, the teeth show up individually, the knuckles in the hand are visible, the ribs are smooth. On the downside, there's a *lot* of stringing to clean up.

There's an undead coming out of my print plate! A teeny tiny cobwebby one!

Rear view is also nice. There's some blobbiness to it, though it's hard to tell if that's due to the silver specks in the filament or actual extrusion blobs

Wanting to improve the stringiness, I printed a temperature tower, this time a bigger one. To get it done in a reasonable amount of time, I cut it down to four layers, using temperatures from 200 to 230. If I can see any difference, I can then do another tower with finer intervals. I set it to use 1.6mm layers rather than 1.5.

The results are impressive, if inconclusive. The cooler layers don't have the tops fused as nicely. The 230 layer has the spike being a bit more wobbly than the rest. There's hardly any stringing.