Since I learned the "Board index > View unread posts" trick, I am finally catching up with a lot more user experiences with this printer.
After reading a lot problems caused by hot-end contamination, the different cleaning techniques and how critical the dimension and shape tolerances of the nozzle are (and how they suffer with "maintenance"), I realized...
Why hasn't anybody thought of anodizing the hot-end? (I did a quick search on these forums and did not find anything. On reprap there's a thread where talk a bit about this but nobody tries anything in the end apparently)
The smoothing results from anodizing should have a lubricating effect for the polymer mass (It would be even better if it is mirror-polished first) and it's also a surface hardening method for the part, so the hot-end should improve on wear resistance.
It has practically no effect on thermal conductivity and it's easy to find suppliers that would agree to perform this for you as a prototype... (You can even do it at home)
There are some concerns though:
Deep anodization adds about 20 micron thickness so it would theoretically decrease the nozzle end diameter by 0.05 mm so this should have to be compensated first or the parameter should be recalibrated.
Also, inside deep narrow cavities or holes is tricky (or impossible?) to control the anodizing process... But I never saw this hot-end inside.
Any experiences or thoughts?