The rod that goes into the extruder idler gear on the extruder arm likes to come loose. this will fix that. i have to push my pin back in after long prints or i end up with extreme under extrusion. this keeps the pin from getting to that point.
I printed it in PLA, but would suggest something stranger just because of the location and heat. have not had any issues after adding this.
The author marked this model as their own original creation.