After I installed my Olsson block from Fbrc8 (with adventures) my Ultimaker 2 hit a sweet spot and is performing particularly well. I printed a tapered cylindrical pillar using 0.06mm layers and really cannot see the layer lines, so cancelled my idea of a pseudo lathe to rotate it in order to smooth it with sandpaper.
However I noticed that the circular cross section is actually a polygon. Difficult to count, but maybe 40 sides, and this is just visible. Is this a function of Cura, or the drawing software, and can it be improved?
The upgrade. What I learned:
Replacing the Teflon piece was a big factor. Of course I should have known if I had been paying attention.
Do not go out and buy a torque wrench and apply 1+ N-M. It is too much. The Olsson plastic one gives you less than half as much, which is plenty.
Of course you have to print it. Either do that with your old setup, or screw in the new nozzle hand tight, and then tweak really gently with a 10 cm or so long 7mm spanner.