3D printed using a wood-PLA hybrid filament, this clip tapers from 4 mm thickness at its base to 2 mm at its ends. Its filleted edges make it more comfortable to handle.
This clip was printed using a PLA filament and is 5 mm thick throughout.
This project addresses a simple prompt: combine two tools to enhance an experience. I designed clips to secure pens to notebooks - two tools I use everyday. I explain my rationale in the sketches below.
Prototyping Process
After sketching, I decided to explore the pen clip/claw mechanism and squeezing concept further. These methods struck me as simplest and required no extra parts. The "claw" and the "squeeze" concepts also seemed to go well together - both relying on squeezing to secure the objects.
In Fusion 360, I sketched a side profile of a book clip with one straight side and one concave side. I made the thickness of the sides 5 mm, and the book clip 150 mm long. The space between the sides (where the notebook will be squeezed into) is 9.5 mm thick. I extruded the sketch upwards 50 mm.
I then drew two squares on the flat surface of the book clip, extruded those squares to form two cubes, and put a hole through them to form the “pen claws”. These claws have a diameter of 9.5 mm, matching the diameter of Muji pens.
I decided to print the clip on its “side” so that it would be strong at its base and hopefully be able to flex over a notebook without snapping. I printed it twice initially - once out of PLA plastic and once with PETG plastic, to compare the plastics’ strength, flexibility, aesthetics, and how well the two materials secured the pens.
Arranging the clip in Cura before printing.
PLA print. The concave side keeps the clip secure when squeezed over the notebook.
PETG print. This translucent plastic is not as rigid as the PLA print.
The prints came out well in terms of the print quality and the functionality - both the PLA and PETG clips fit snugly on my notebook and pens snap into the claws. Interestingly, the PETG print seems to be losing some strength the more I use it, so now pens aren’t as secure in the clips.
After user testing these early prints, I received helpful feedback for iterating on this idea. Three of the common points were:
1. The clips are a bit bulky to fit over a notebook and carry around in a backpack.
2. There's plenty of space for a second set of claws to carry another pen.
3. The concave side of the clips bows out when fitted over a notebook.
The above version is 2 mm thinner throughout, has claws for a second writing utensil, and rather than using a concave side for squeezing a notebook (which bowed out in early versions), its curved side flattens out to prevent bowing over a notebook.
The below image shows a different approach. I used a wood-PLA filament, experimenting with the clip's flexibility and aesthetics. I tapered its sides from 4mm at its base to 2mm at is ends. I filleted all edges to create a smoother feel and look.
