At this point, I felt confident to begin printing test key caps out of my transulecnt PETG filament. I am still unsure as to whether I will print my final keycap set from this material, or will instead opt for standard matte PLA, however this is a good test regardless, as I am sure that I will print the case of the keyboard from this material, and I want to be certain that it will be suitably translucent, to let the under-glow from the PCB shine through.

The keycap seen bellow, and on the right hand side of the video, was printed with standard 0.2mm layer height. The keycap seen on the left of the video was printed with the 0.08mm layer height as used in previous iterations. I originally thought that the reduced layer height would increase the quality of the keycap, and help make the material more translucent. However it seemed from this test that that the opposite was true, the 0.2mm key cap performed much better. This is good to know as I will apply this to the keyboard case.

It is clear that the translucent PETG performs better with larger layer heights, as opposed to the red PETG that I had previously used for prototyping. 

Alongside the different manufacturing process, I had also made a number of tweaks to the profile of the keycap, and the thickness of the walls, in order to increase strength when attached to switches, and to better the sound of the keycap.

For this second trial, I increased the clearance in the cut-out in the centre column to allow the keycaps to be attached with less difficulty. I also decreased the width of the centre column, in order to prevent the issue with interference between the switch and the key cap.

This worked to an extent, although I did did still encounter some problems with the width of the column - when the pressing force was applied at an angle, the column would interact with the back of the switch casing, causing a slight bump as the stem of the switch descended.

I had at this point encountered another problem; through my making of the column thinner, and the cross cut-out in the middle wider, the walls had begun to grow exceptionally thin. This lead to cracking as I removed and re attached the keycap. Across the course of only a few removals, the cracks have propagated on both sides of the column, leading to a very loose fit when attached to the switch. The reason for this is is obviously the scale of the model, which leads me nicely onto my next point.

The quality of the keycaps is very poor - the layer lines are very visible and the font is rather invisible. The small scale of the keycaps requires very fine detail when printing  - a level of precision which my 0.4 mm nozzle cannot achieve. A way to combat this will be to try and reduce the layer height which is something which I aim to change for the future iterations. This should not only help with the quality of the production, but should also reduce the cracking of the material.

Another problem that I identified at this point was the sound. The sound and feel of a custom keyboard is a large part of its appeal, and this is something which I would very much like to focus on. These PETG keycaps sound incredibly plastic and hollow - a world away from the deepness of thick ABS keycaps. I will combat this by increasing the thickness of the walls for future keycaps. I believe that this will help to aid the sound - the walls are very thin compared to my keycaps which I have been using as a referance.

For future iterations,  I am going to try to redesign the profile of the keycap closer to an XDA or DSA profile, in which each row of keycaps has the same flat profile. I like the look of these, and I like the idea of not having to spend countless hours fussing over minute details with curvatures and heights. I will also try and use PLA in order to determine which material will be best suited for the creation of my new keyboard. I like the idea of a translucent orange case with matte white keycaps (PLA), however I must first assess the functionality of this.