Vase Mode Keycap Mixers

This is a set of Cherry MX compatible keycap designs intended to show a way of printing in spiral vase mode, with additional options for adding a pseudo-doubleshot style text and  a two-piece cap for inserting printed legends. They also all support the option to insert “O” rings.

Design Notes

Originally started to be a simple design, it experienced a little feature creep when I had additional ideas and ended up as a more interesting final set.

The components of this set can be combined in fourteen different ways:

• Basic flat cap:  Plain / embossed legend
• Basic chamfered cap:  Plain / embossed legend
• Two-piece flat cap:  Plain / embossed legend / with printed insert
• x Any of the above with colour change option (best for embossed legends)

Printing these keycaps properly relies on a slicer trick, setting “Slice Gap Closing Radius” to a value that makes it draw two completely separate perimeters on a layer. This is done with a thin (0.02mm) cut in the model between the start of the stem and the outer wall, and setting the slice gap closing radius to around 0.1 or 0.09mm. This causes the sliced path to hop instead of extrude the perimeters that it would have done between those points.

The reason this is needed is that if there were perimeters joining the central stem and the outer wall all the way up, (it would be stronger) but the keycap would not sink into the switch enough to actuate a key press.

I know this works in PrusaSlicer and SuperSlicer but I have not tried other slicers yet.

Known limitations:

1. The stem is rather fragile, but I have not noticed a breakage in normal use.
2. I have not yet found a way of printing more than one at once, so printing a whole set would take a long time.
3. Must be printed face-down only.
4. Straight, flat key profile may not mix well with other profiles, but they could be modified to be tapered.

Link to design: https://www.tinkercad.com/things/dl9jxIy60dB?sharecode=eFtZrpGboAAgx5BXlPGhiT89UuA0ub7XH3J6n5MG64M

Print Settings

• 0.2mm layer height, spiral vase mode.
• Set “Slice Gap Closing Radius” to around 0.09mm.
• 4 or 5 bottom solid layers for basic and inner caps.
• 2 bottom solid layers for the shell.
• Try 0.5mm outer perimeters if using a 0.4mm nozzle.
• I was using 98% flow rate, but try changing if your stems come out too tight / loose.
• The shell looks clearest when printed on a smooth sheet.
• If changing colour, set change at layer 3. Alternatively change again at layer 5 or 6 if you want more of the top colour all the way down, or even a third colour.

There is an obvious seam on the basic keycaps, so if using embossed legends, I find the best seam placement is on the back side (side of the top of the legend.) This way they are least likely to be noticed at normal use angles. It helps to check the alignment in the sliced view, and if it's not where you want to be, try turning the cap or text 90 degrees at a time to change this.

PLA or PETG don't seem to need any different slicing settings, but I did find that different colours/brands of filament may shrink differently so the fit tightness may vary on the two-piece caps. You want a fit that is snug enough so they don't fall apart but not so tight that you can't pull them apart again without risking breakage.

The included .3mf file(s) have the full slicing settings as well as one with 0.4mm embossed legends (compatible with PrusaSlicer 2.6 and above.)

A template for printed inserts is included as an .svg file. This is editable in Inkscape or Illustrator.