Anti-tilt and rotation techniques for a touchsurface assembly having translating keys

A keyboard, comprising:

• a plurality of keycaps, each keycap of the plurality of keycaps having a touch surface for receiving a press force that moves the keycap from a unpressed position toward a pressed position, the unpressed position and pressed position separated in a press direction and a second direction orthogonal to the press direction;
• each keycap of the plurality of keycaps also having ramp contacting features comprising first and second angular protrusions having first and second protrusion angles relative to first and second side portions of the keycap, respectively,
• wherein the first angular protrusion and the second angular protrusion extend in a plane parallel to a plane of the touch surface, and
• wherein the first protrusion angle of the angular protrusion and the second protrusion angle of the second angular protrusion are each angled in a direction incident with the first side portion of the keycap;
• and
• a base having, for each corresponding keycap of the plurality of keycaps, first and second ramps that contact the ramp contacting features of the corresponding keycap, and guide the corresponding keycap in the press direction and the second direction as the corresponding keycap moves from the impressed position toward the pressed position, the base also having, for each corresponding keycap of the plurality of keycaps, first and second angular features configured to contact the first and second angular protrusions of the ramp contacting features of the corresponding keycap, respectively, to resist rotation of the corresponding keycap as the corresponding keycap moves toward the pressed position.