The size of each keycap is different so it's important to take note of all the angles and curvatures.
We'll started by taking measurements of the top and bottom of keycaps using calipers.
In CAD software, we drew up simple sketches and lofted between them to create the basic shape.
To create the curvature, we subtracted an oblong cylinder from the top surface, which is an easy way to create a slight contour. Take note of the angle, each row of keys are differnet.
Measure the placement of where the internal support connects to the switch. Use the stem geometry found in our 123D design file or import the stemKey.stl file into your CAD program.
You'll want to adjust the tolerences on the stem when printing with FDM printers. Select the inside walls and push them out by about -.4mm.
Add bottom support structures when printing with FDM printers. Use the custom support structures found in the 123D design file or import the stemSupport.stl file. You can also build your own by projecting the sketch profile of the connector surface.
Draw your artwork inside your favorite vector program or search online for .svg files. Import, extrude and combine it the the rest of the geometry to finish up the keycap design.