KeyboardKeys
Hardware Engineering

Reading Force Curves: The Only Switch Graph That Matters

Published by KeyboardKeys Research Desk · Technical Reference

Core Takeaway: Force on Y, travel on X — the curve shows the bump, the spring, and the truth that adjectives cannot.

Switch marketing says "smooth" and "bumpy." The force curve shows it: a graph of force (grams) against travel (millimeters) measured as the stem presses down. Ten seconds of curve-reading beats ten forum threads.

Anatomy of the curve

FeatureWhat it shows
Starting forceSpring preload — higher starts mean heavier feel immediately
The bump (tactile)A rise-and-fall mid-travel — its height and width ARE the tactility
Click eventA sharp spike-drop at actuation
End forceBottom-out weight — the fatigue number

Linears print smooth ascending curves. Tactiles print a hill mid-travel — the hill is the bump, and its steepness is sharpness. Browns show a barely-there hill; Holy Pandas show a mountain. The graph ends the argument.

What lubing does to the curve

  1. Nothing to the shape — lubing changes friction, not spring force. The curve's form survives.
  2. Removes "scratch" — the high-frequency friction noise of unlubed sliders; the curve can even show it as jaggedness.
  3. Spring ping: a sound issue — lube or swap springs to silence it.

Where to find curves

Manufacturer curves exist but run marketing-soft; community force-curve testers (ThereminGoat's archive is the standard) publish honest measured curves for hundreds of switches. Cross-reference any switch on this database with its curve, and "creamy," "thocky," and "marbly" resolve into geometry — which is where they belonged all along.

Advertisement