Short-Point Colouring Pencil/Pencil-Crayon Sharpener Adapter

thingiverse

Certain brands of high-quality colouring pencils have thick, fragile wax cores that lay down great colour but break or crumble if you use standard sharpeners. While Prismacolor makes a special short-point sharpener for their pencil-crayons, it's rather expensive and not always reliable. It uses roughly the same sharpening angle as jumbo pencils, and companies such as Staedtler and KUM make good quality dual-hole jumbo sharpeners quite cheaply. These adapters help keep narrow pencils centred in wide jumbo sharpener holes. I've made two angles: * 26° for Staedtler sharpeners; * 30° for KUM sharpeners. The fit is approximate, so use whichever one feels like a better fit. The inner bore of the adapter should be a smooth running fit against the pencil to allow it to sharpen freely. The pencil holder in the background is my design based on Laurie Gellatly's Customizable fancy pencil holder with the following parameters: number_of_pencils = 24; slope_angle = 25; pencil_diameter = 8.2;