[bojan]

After more than 10 years of use, last couple of days I have a problem with my 3D printer head (MK8, 0.3 mm nozzle).
It seems the resistance to push the filament (ABS) through teflon tube of the hot end increased for some reason, and I at this time I can't figure our the reason for this..

It started with new filament reel, but even with old one the problem is here now.
I tried with higher temperature (250~260°C), but no results.
Then I put the new nozzle, new teflon tube.. no joy - it seems the filament gets stuck inside, so it is even not easy to pull it out, from either side when cold.

In the past, I had insulator wool around hot block, but stop using it as it was not doing much (then).

Did anybody have the similar problem and what was the solution?