I think you may have nailed the issue.

I'll try the mod and ensure the tube end is sitting flush, with a clean cut end.

Maybe increasing the fan speed will also help cool the tube and prevent jamming in the final section of PTFE.

Will let you all know if it works!

Quote Originally Posted by PlastiTech View Post
My guesses are that you either have a problem with heat creep, or the PTFE tube is not flat against the heater block, or the nozzle itself needs to be replaced.

Heat creep occurs when heat from the heater block "creeps" up the PTFE tube and out of the "melt zone." This softens and may even melt the filament before it reaches the heater block and the nozzle, which are the only places where it's supposed to melt. Heat creep can be caused by the heatsink on the hotend not being cooled enough.

If the PTFE tube is not pushed down flat against the heater block (or nozzle), or if the end of the PTFE tube has not been cut flat, then melted plastic can ooze out from the gap between the tube and the heater block, causing a jam.

If all else fails, try replacing the nozzle.

Over time, the PTFE tube may move upwards in the hotend, creating that naughty gap between the end of the tube and the heater block. There is a fix for this on Thingiverse. Here is the link : https://www.thingiverse.com/thing:4220059