The DES Keycap Profile: 3D Printing and Using Very Nice Keycaps

The Distorted Ellipsoidal Saddle (DES) profile is a sculpted Cherry MX keycap profile with a unique look and feel. I’m currently using MT3 and greatly enjoying it, but I’m always looking for potentially better options. Since I just built a new keyboard (the Charybdis), now seems like a great time to try out a new keycap profile too. While researching the Charybdis, I learned that Quentin Lebastard of Bastard Keyboards, designer of the Charybdis, uses DES and provides a shining endorsement: “I don’t plan on moving away from DES though – shoutout to Asymplex, those are the most comfortable keycaps I’ve ever used.” I produced high-quality keys in the DES profile – here’s how and my thoughts on using DES keys.

BLUF: The DES profile is great! I love it and recommend it. The best way to print them (or any keycaps) is at a 45-degree angle with the stem and the keycap printed in two parts assembled post-printing with glue.

What is the DES Profile?

The DES profile was created by Pseudoku (aka MemeticDevices) who initially announced it in 2019. DES is lower profile (shorter) while still using Cherry MX stems, has key designs optimized for thumb clusters, and features a unique shape. The profile is sculpted, meaning that the keys are shaped differently for each row, so for example the “Q” and “A” rows have different shaped keys. I’m a big fan of sculpted profiles as they improve key reachability guiding the fingers to the right places. Pseudoku’s On the DES keycap profile article explains the origin of the design, its unique features, and more in detail.

FDM 3D Printing the Key Caps

I previously explored 3D Printing High Quality Keycaps so I started by applying that knowledge to the DES profile keys. Throughout this journey, I used Pseudoku’s PseudoMakeMeKeyCapProfiles project which has OpenSCAD models to generate the keycaps.

No Legends (This Time)

This time around I’m not printing legends on the keycaps. I found that I didn’t use the legends; they serve no practical purpose. Furthermore, due to changing my mind on the layout and experimenting with new mappings, the legends end up wrong as compared to what the key does. Legends add a lot of complexity to the process because they need to be added to the models. Legends cause a lot of waste and take a lot of time, as changing filaments is a very wasteful and time-consuming process. Printing legends on keycaps requires between 10 (for flat) and 60 (for 45-degree oriented) filament changes. On my Bambu Lab P1S with AMS, 25% of the total filament used ends up being purge waste, and an hour is added to the print time. On a multi-toolhead printer like the Prusa XL, the waste and time cost will be less, but still present.

Printing Flat

My first attempt was to print some keys flat. I didn’t notice that the stem didn’t go all the way down, so the printer tried to print the stem starting in mid-air… and that didn’t go well.

I discovered uqs’ fork of PseudoMakeMeKeyCapProfiles which includes a change to fix the models to sit flush on the XY plane. It also includes a Makefile which makes generating the STLs a lot less tedious.

I was then able to produce my first R3 DES keycap. I used the Bambu Lab P1S with the 0.2mm Nozzle.

Keycaps printed in this way are printed quickly and reliably. They feel nice too; the layer stair stepping is too fine for (at least my) fingers to detect.

Printing at 45 Degrees

These keys came out looking and feeling great.

One gotcha I experienced is that the keys must be spaced far enough apart. The printing failure rate rises dramatically the closer the keys get to each other. I found that spacing them 30mm apart is about as close as they can get to print reliably.

The big challenge is with the stem; it only printed correctly maybe 50% and other times turned into spaghetti ruining that key or sometimes all the other keys being printed alongside it. My initial thinking was to try subtly different orientations, spacing, and changing print settings such as cooling and temperature, but after many attempts, I was no closer to a solution.

Then a great idea dawned on me: why not print the stem separately?

Separate Stems: Solving the Stem Quality and Durability Problem

If the stem is printed separately from the keycap, each can be printed in its ideal orientation making printing more reliable, improving appearance, and increasing strength. And since they’re separate prints, each could use a different material providing some wonderful advantages:

• Silk PLA and other “weak” filaments can now be used for the keycaps. Even the Bambu PLA Metal isn’t great for stems. Print the keycap using something decorative but weak, and print the stem in something else.
• A better filament for stems can be used, such as PETG. PLA, PLA+, and Tough PLA produce stems that are good, but they still sometimes break. For instance, I seem to hit the “3” key on the bottom edge which is an awkward force for the stem to handle so I broke the stem on that key after about 6 months of use. PETG handles this force much better, flexing instead of breaking, producing more durable stems.

The stem and keycap are not printed as one multi-material print for two reasons:

• A multi-material print would require many filament changes which is very time-consuming and wasteful.
• A multi-material print couldn’t use PETG for the stem and PLA for the keycap because PETG and PLA don’t bond.

Therefore, I’m gluing the keycap and stem together using Gorilla Glue.

For my DES keys, I’m using Bambu PLA Metal Cobal Blue for the keycaps and VoxelPLA PETG+ for the stems.

I modified the PseudoMakeMeKeyCapProfiles project to create stems and keys without stems for all 5 rows of the DES profile, see my fork at https://github.com/candrews/PseudoMakeMeKeyCapProfiles for my modifications. Run make all to produce the STLs.

To make it even easier, I shared my separate keys and stems models and 3mf:

• MakerWorld: DES profile MX keycaps, separate stems and keys
• Printables: DES profile MX keycaps, separate stems and keys

On a Bambu Lab P1S, printing the 56 keys and stems for a Charybdis requires 10 plates (two plates for each of the 5 rows).

How is the DES Profile to Use?

The DES keys look and feel great. The difference between MT3 (with which I started) and DES is striking. MT3 has a nice “bowl” hugging the finger providing a gratifying sensation while typing. DES also has the bowl concept, but it’s elongated, guiding the fingers between columns as opposed to MT3 which only guides to the center of a key. Staying within a column is easier thanks to DES’s guidance. The DES shape also makes it feel more obvious when switching columns, such as when the pointer finger moves from “f” to “g,” which helps reduce mis-presses.

For column staggered or ortholinear keyboards, DES is superior to MT3. In my opinion, it is just that simple.

For the “regular” keyboards with row stagger, DES vs MT3 may be a bit more nuanced. With row stagger, DES’s column-guiding shape isn’t beneficial; MT3’s bowl guiding to the center of the key may be the better design. I suspect DES and MT3 would both be great, but MT3 may be better for this keyboard design. However, I haven’t tried either profile on a row staggered keyboard, so these thoughts are more theory than practical review.

Where to Buy DES Profile Keycaps

If you don’t have a 3D printer or don’t want to produce your own, I found them for sale:

• Pseudoku (the creator of the DES profile) sells keycaps on his store, Asymplex
• Skree sells DES Keys in black/white/clear and custom colors
• 3dkeycap sells DES keys

But if you want unique filaments (such as the cobalt blue metallic I used), you’re going to have to go the DIY route.

The DES Keycap Profile: 3D Printing and Using Very Nice Keycaps by Craig Andrews is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.