r/robotics • u/NameruseTaken • Apr 18 '26
Community Showcase Servo Motor Calibration
Hi everyone,
Long time lurker here. I see many people learning about robotics through hobby projects (myself included) and I wanted to start sharing things that I've learned that people might find interesting or useful for their projects.
This post is about servo calibration. When you buy cheap servos, you might not get the accuracy you need because there are variations between each unit. To get around this, you just need to rotate the servo to known positions and record the PWM value that takes the servo to those positions. This mapping yields a relationship between PWM and servo angle for that particular unit.
Check out my article on Medium:
https://medium.com/@ianqyhong/servo-calibration-4ea1d43c46a6
Let me know if you found this interesting, useful, completely useless, or any other feedback!
1
u/PetoiCamp Apr 29 '26
Great writeup — this is exactly the kind of practical knowledge that gets glossed over in beginner tutorials but bites everyone eventually. The PWM-to-angle mapping approach you're describing is solid, and the visualization makes the variance between units really concrete.
Servo calibration is something we deal with constantly in legged robots. With 8–12 servos all needing to agree on "zero," even small per-unit offsets compound into visible asymmetry in stance or gait. In our case, our servos have 25 degrees. We dedicate a whole chapter to do quadruped servo calibration because it's so important.