3D printed bearing for coffee grinder

Update: Hello from 2024! After 7 years the original post has been removed from Reddit. You can download my fixed STL file here. My Hario Skerton has not been in daily use for some time now, but the printed bearing has hold up well.

I am a coffee person. I enjoy good coffee and I do things for it. Today I 3D printed a bearing for my coffee grinder Hario Skerton in order to produce more consistent grind.

I have access to my school's printer (MakerFarm 6" Prusa i3). I had printed once before this. I used Repetier Host with Slic3r.

The model I got from this Reddit thread. There is STL and Solidworks files available. I had to fix the STL file with Slic3r (it was non-manifold) before Repetier Host accepted it.

First print was not good. The walls were very coarse and ugly. I stopped printing and sliced again with smaller extrusion multiplier (from 1.2 to 1.05) and lower extrusion temperature (205 -> 200 °C). The result was much better, though the walls were melting and falling inwards.

The third one I got right. I increased layer height to 0.4 mm and the result was good.

First print on the left

At first the bearing was a bit too tight when installed on place. After a little sanding, the fit was perfect.

The bearing installed

So, how is the grind?

I haven't done any actual comparing tests but there is notably less wobble in the grinder. I was happy with the grind without the bearing, I just thought this was a cool project to do! :)