I own a Creality K1C and feeding the filament into the PTFE bowden tube is a hit or miss depending on how awake or how much in a rush I am. Decided to take luck out of the equation by making this adaptor to “funnel” the filament into the PTFE bowden tube at the back.
It is a simple contraption that uses friction to hold on to the PTFE tube at the filament sensor end. On the other end is a 7.5mm (diameter) funnel to guide the filament into the 2.0mm opening of the PTFE bowden tube. That's 3.75 times wider and you should be less likely to fail.
I would recommend printing it in fine quality (0.12mm) due to the slight slope/ angle used for the friction hold.
Changelog
How I printed it
The author marked this model as their own original creation.