Mounting

The S1 measures the shaft through a magnet on the end of it. Get the magnet centred and at the right distance, and everything else follows: calibration passes, and the encoder stays quiet.

The magnet

The on-board AS5600 reads the direction of a magnetic field, so it needs a diametrically magnetised magnet: north and south across the diameter, not along the axis. A common size is 6 mm across and 2–3 mm thick, neodymium.

S1-ready motors come with the magnet fitted and centred. For your own motor:

1. The motor needs a rear shaft (a “dual shaft” motor). Clean its end face.
2. Glue the magnet centred on the end face with epoxy or cyanoacrylate. A small printed cap that slips over the shaft makes centring easy.
3. Let it cure fully before you run the motor: a magnet that shifts later ruins the calibration.

Caution

An axially magnetised magnet (north on one flat face) looks identical but does not work: the encoder sees no rotation. If calibration fails with a magnet that looks right, this is the first suspect.

Mounting the board

The encoder chip sits on the underside, exactly at the centre of the four mounting holes. Mount the S1 encoder side down, so that:

CentredThe shaft axis passes through the centre of the four holes. An off-centre magnet makes the reading wobble once per turn.

0.5–3 mm gapBetween magnet and chip. Magnet too strong: move the board away. Too weak: move it closer.

No steel in betweenUse brass or nylon spacers near the magnet if you can.

Fix it with M3 screws through the four 3.2 mm holes (centres 30.6 × 30.65 mm) on standoffs, or on a printed adapter plate that centres on the motor’s rear.

Checking it

With the S1 powered and connected to Tercio Control:

1. Open the motor’s Diagnostics tab. Magnet too weak or Magnet too strong under Health means the gap needs adjusting.
2. Disable the motor and turn the shaft slowly by hand through one full revolution. The position on the Control tab should change smoothly by one turn (360°), without jumps.
3. Run Calibrate. It checks that the encoder moved the expected amount; if it did not, it reports Calibration failed.

Heat

The TMC2209 on top of the board turns part of the motor current into heat. Up to about 1.2 A it is comfortable in still air. Above that, or in an enclosure:

• Give the board airflow, even a small fan.
• Lower the hold current if the motor stands still most of the time (50 % of run current by default).
• Watch the board temperature on the Diagnostics tab. The S1 warns 10 °C before Shut down at (95 °C by default) and switches the motor off when it gets there.

An encoder elsewhere

If the encoder cannot sit on the motor, for example after a gearbox, use an external AS5600 or AS5048A on the 12-pin connector instead. See Encoders.