Atlas: committing to Kailh Choc v2
Atlas's switch choice moves from Choc v1 with custom-stretched key spacing to Choc v2 at native MX pitch. Same low-profile body, but every keycap on the MX shelf now fits.
Atlas’s switch choice is settled: Kailh Choc v2 (PG1353), not Choc v1 (PG1350).
The pattern up to now: Choc v1 at a custom 20 mm column pitch, wider than Choc’s native 18×17 mm and wider even than MX-standard 19.05 mm. It worked. It also pinned the keycap shelf to MBK and a handful of Choc-specific sets, with custom-width caps required to fit the 20 mm geometry.
Carrying a one-off pitch on a Choc-only keycap shelf isn’t paying for itself anymore.
What v2 changes
- MX-compatible stem. v2 swaps v1’s 3.4 mm rectangular Choc stem for a 5 mm MX cross. Low-profile MX keycap profiles (DSA, SMOLO) drop onto Atlas. Choc v1 caps (MBK, MCC, CFX) don’t.
- Standard pitch. With MX-stem keycaps, 19.05 mm pitch is the obvious default. The custom 20 mm geometry retires; off-the-shelf low-profile MX caps just fit.
- 15 × 15 mm body, a touch taller, plate required. Switch body footprint matches v1, but the housing sits a hair higher and needs a top plate (v1 can run plateless). Hot-swap stays on Kailh Choc-style sockets, not MX sockets.
Stem comparison, via beekeeb.
What it costs
Choc v1 keycap sets (MBK, MCC, CFX) don’t fit Choc v2 stems. Anyone with a v1 keycap stash loses that compatibility on Atlas. The MX low-profile selection is much wider, and custom-spaced v1 layouts already left most of the boutique Choc sets behind, so that trade lands the easy way. The board itself sits a hair taller than a v1 build, but stays well inside low-profile territory.
What it changes for the PCB
The switch footprint swaps from PG1350 (5-pin) to PG1353 (3-pin). Key pitch moves from a custom 20 mm to standard MX 19.05 mm. The case has to gain a plate (v2 won’t run plateless), and the switch openings follow standard MX low-profile dimensions instead of a one-off pitch.
Pin layout comparison, via beekeeb.
Why this was worth doing
The 20 mm custom pitch made sense once. It also forced the plate, the case, and every keycap set into a one-off geometry. Choc v2 keeps the low-profile feel that made Choc the right family in the first place, and it puts Atlas on the mainline MX keycap shelf at the same pitch every other low-profile split is already shipping. The bill of materials gets shorter, keycap options open up, and the plate and case settle onto standard dimensions instead of a one-off.