Build · Testing

Prove it’s safe before you prove it’s fast.

Radio binding, fail-safe, and a disciplined first power-up are what stand between a working robot and a runaway one. Every powered step on this page happens inside a compliant test box — no exceptions.

Fail-safe prevents injury. When the transmitter turns off, all robot movement must stop immediately — drive, weapon, everything. Test it before every competition and after any receiver or transmitter change.

Fail-safe setup

Configure fail-safe through the transmitter menu — mandatory for competition.

Step 1

Set the transmitter to safe positions

Robot powered, transmitter on: drive channels (1 & 2) centered at neutral; weapon channel (3) full down (weapon off).

Step 2

Configure fail-safe in the transmitter menu

Find the fail-safe settings (commonly under "System," "Functions," "RX Setup," or "Failsafe"). Set channels 1 & 2 to 0% (neutral) and channel 3 to −100% (weapon off). Avoid "Hold" mode — always set specific position values. Menu paths vary by model; never rely on factory defaults. Save before testing.

Step 3

Test it

With the robot secured in the test box and the weapon disabled, turn the transmitter OFF. All motion must stop immediately. If anything keeps moving, repeat the setup.

Receiver binding (FlySky FS2A)

Step 1

Prepare the receiver

Hold the bind button on the FS2A while powering it on — the LED flashes rapidly.

Step 2

Put the transmitter in bind mode

The procedure varies by FlySky model; check the manual.

Step 3

Confirm

The receiver LED changes to a slower, steady pattern when bound. Power-cycle the transmitter to verify, then move the sticks and confirm the receiver responds.

ESC calibration

Speed controllers must learn the transmitter’s signal range:

Turn on the transmitter with sticks centered and trims neutral
Move the stick to maximum throttle
Power on the ESC and wait for its tune to complete
Move the stick to minimum position
Wait for the second confirmation tone
Test the throttle, then power-cycle

First power

The very first battery connection goes through a smoke stopper (see the electronics guide) — it catches wiring shorts before they destroy components. Only after a clean smoke-stopper test does the robot get full battery power.

The functional test protocol

Run this in the test box, in order:

Load-in: robot in the box with weapon restraints installed; transmitter on and placed on a table where nobody will touch it; power the robot and confirm binding; close the box completely before picking up the transmitter.
Drive test (weapon restrained): drive forward, backward, turn both ways. Then put the robot in a continuous spin, keep pressure on the stick, and switch the transmitter off mid-maneuver — everything must stop immediately.
Weapon test: only after the drive fail-safe passes, and only per the official sequence below.
If anything moves unintentionally at any point: power off immediately and troubleshoot before continuing.

The authoritative step-by-step is the functional safety-test procedure in the safety rules — the same sequence used at event inspection. Passing it at home means inspection day is a formality.

Something wrong? Troubleshooting →Ready? Your first event