Steno key switches

From Plover Wiki

Due to how multiple keys must be pressed simultaneously, there are two properties that are useful to have in a mechanical keyboard switch for steno: a light actuation force on a linear switch.

The light actuation makes it easier on your hands. For a chord like TKPWHRAOEUGD (gliding), you are hitting 8 keys with your left hand. That means that whatever switch force you need to depress one key, you have to push 8-times as much. For a 80cN (~80 grams, ~2.9 oz) switch, that’s 640cN (~640g, ~22.6 oz). For this reason, your wrists will have a much easier time working with your machine if its actuation force is as light as possible.

How many keys are in the average chord?
1: 23

2: 221

3: 1115

4: 3247

5: 6168

6: 7820

7: 7293

8: 5069

9: 2707

10: 1126

11: 331

12: 90

13: 21

14: 3

15: 1

The linearity is recommended because it’s been found that the tactile feedback that one gets from an individual switch is not as useful when you are receiving 4-10 of those feedbacks at once. The brain just doesn’t process all the fingers’ feedback in a useful manner. And since the bump usually requires a small addition to the actuation force, we recommend keeping it linear and simple.

Professional steno machines, historically, always bottomed out (meaning the keys are pressed until they can no longer travel; the bottom.) Newer machines use more complicated mechanisms for detecting key travel, often using magnets and the hall effect to determine where the key is, allowing for customizable actuation points. The typical force required for a modern steno machine is between 10cN and 20cN, with some extremes on either end for personal preference. The travel of a typical lever steno machine is usually between 2mm and 30mm. The lower end is found in machines like the LightSpeed (nonlever), where the higher end is around the maximum that you can configure a lever machine to stroke.

Most of the mechanical switches have a 2mm actuation point and 4mm travel/bottoming out, but some community members have found that “speed switches” with an earlier actuation point (usually 1.1-1.4mm) are better for steno due to their increased sensitivity.

Switch Stat Note Machines
Kailh Choc Pink Pro 20 cN linear The lightest stock option available, though the reduced travel distance makes it feel comparatively heavier All Nolltronics boards and the Starboard use this switch
Kailh Choc Nocturnal 20 cN linear, silent
Gateron Clear / White 35 cN linear A popular stock option available on the market All StenoKeyboards boards and the TinyMod use this switch
Matias Red 35 cN linear Feels heavier than 35 cN switches due to having a “flat” force curve. Matias also has a different stem from Cherry SOFT/HRUF uses this switch
Cherry MX Red 45 cN linear
Kailh Silver 50 cN spring* linear Has an early actuation (1.1mm vs 2mm)
Cherry MX Brown 45 cN bumpy While not ideal compared to other options, this switch is still a better choice than blues, blacks, and other Cherry switches
Kailh Choc Red 50 cN spring* linear The Georgi uses this switch
  • The Kailh silvers and Choc reds use a spring that would cause a 50 cN actuation point at 2mm, but since they actuate earlier (1.1mm), the force required is nearer to 35 cN.

There are other methods to decrease actuation force for even these switches. This includes:

  • Putting SPRiT 15g Choc springs into the Kailh Choc Pink Pro
  • Putting the Gateron Clear’s 35 cN spring into the Kailh Silver for its earlier actuation point.
  • Trimming the springs of a linear switch by several mm to reduce force.
  • Using an aftermarket spring with lower forces, such as a prototype 20 cN spring that isn’t yet released to the wider market.
  • Removing the leaf-spring (not the primary spring) in the Matias Red switch to make the force curve less flat.