Locking key for Ultimaker filament feeder (aka "extruder")

thingiverse

Grow weary of the feeder constantly detaching from the Ultimaker frame when pushing filament manually? Worried it will fall off during movement of your box? Simply attach this accessory in the available space above the extruder arms to secure it. Although it would be ideal not to require manual filament insertion, at least now only one hand is needed for the task. Update: Customizable for any size or fine-tuning! Printed with 0.1mm layers, 0.8mm walls, and 35% infill (reducing may still be acceptable). The design is entirely parametric, allowing further improvement.