What is causing this?

[3DPLUS]

Try to increase the Noozle's degree

[ralphzoontjens]

I have this too on the 3drag printer. It can be related to:
- the part leading to the nozzle being wider than the coupler piece before the extruder, so that it requires carefully removing the filament every time.
- the printhead assembly not being tightly screwed leading to gaps where the filament can slightly expand. Sometimes in this case you see leakage.
- air bubbles forming in the filament when heated due to undried storage - this is steam from moisture and causes the filament to expand, making it harder to remove from the printhead. It usually only occurs after many months of storage.

[curious aardvark]

do you have a small white ptfe tube that sits on top of the nozzle, and guide the filament through the hot end ?
If not fit one.
I think you said you got one with the machine but there wasn't one in the hotend when you took it a part.
There probably should have been one in the hotend from day one.
You might have had your plastic feed tube pushed down far enough tht it could print. That might have moved.
The ptfe tube is a good idea anyway :-)

[Swiffi]

Try to increase the Noozle's degree

What do you mean by this?

[Swiffi]

I just replaced the old ptfe tube since I experienced an awful clog. http://imgur.com/beTTUcD . The nozzle was surprisingly clean, but it is currently soaking in an acetone bath. Currently I replaced it with a high-lubricity .6mm nozzle to try and print wood. I still have no idea of what caused the first images jam.