Hardware overview

SO-101 follower

The physical platform documented here is an SO-101 follower arm assembled from printed parts and serial bus servos.

The current build uses six STS3215 servos with a 1:345 gear ratio and an FE-URT-2 controller board. The controller has been tested over USB serial (the Linux device name may change, for example between /dev/ttyACM0 and /dev/ttyACM1).

These details describe one experimental build, not a universal SO-101 bill of materials. Record the exact servo variant, gear ratio, controller revision, supply voltage, and cable arrangement when reproducing the setup.

Power notes

Servo supply voltage and current capability matter under load. A bench supply can reveal voltage sag and approximate current draw, but brief current peaks may be missed by slow telemetry polling. Do not infer that a servo has adequate torque solely from a low displayed current reading.

Before increasing supply voltage, verify the safe operating range of the exact servo and controller hardware.

Record your build

Item	Record
Servo model and ratio	Exact label / seller specification
Controller	Board revision and firmware
Power supply	Voltage, current rating, wiring
Host	OS, kernel, USB serial device
Printed parts	Material, slicer, settings