day 3- mid print under extrusion  

day 3- mid print under extrusion

Started a print today for a toy for my Son after getting my printer on Friday i have zero experience really with 3D printers all though i often get them made at work as i'm an Engineer.  So far i have been blown away with the ease and quality of the print but today i have had a problem 3mm from the top of the print i got under extrusions caused by the extruder clicking the surface was perfect till that point i've only printed with PLA so far.

i followed this guide  https://help.prusa3d.com/en/article/clogged-nozzle-hotend-mini_112011

so to summarise.

• Unloaded and checked the Idler tension as i had dust on the teeth.  
• 5 cold pulls- with all the boden system, with the top fitting still in place, and finally without the ptfe tube direct into the hotend.
• replaced the ptfe tube in the hot end (seems like a weak point)

When i measured the ptfe tube it was 0.4mm short so i'm guessing it's shrunk with the heat but really not impressed that after 3 days i've had to replace a part already.  I've ordered some more ptfe and am printing a jig but surely this shouldn't have happened?

Can the tubes be reused when they have been shrunk or is their a hard stop inside the extruder? If you have to push the hotend/heat break up when you fit a new ptfe tube it feels like some wiggle room exists and just reusing the shrunk tube might be a solution?