If you browse back through this blog you will be able to see how one of my students has attempted to design an improved pencil sharpener.
His designs started out as a desktop model and by looking back at his specification for the design decided that something more portable and easier to use for small hands would be a better route to follow.
His next design was really quite innovative and involved fold out cross pieces that formed a handle for better leverage. It also incorporated a standard metal pencil sharpener to do the main job of sharpening… However he was still not entirely satisfied. It was now close to becoming a marketable product but having to rely on another manufacturers sharpener wasn’t really a good idea, and the pointy ends of the fold out handles wasn’t very aesthetically pleasing… So…
The final iteration of his design addressed these issues… And matches the specification beautifully as you can see in the photos.
I firmly believe that without being able to do 3D printing for his prototypes and adopting an iterative design process this student would still be looking at a chunky desktop product and would never have developed his design in such detail.