PiCar-X Front Wheels Turn Fully to the Right During Calibration and Stay Locked in That Position

[bozdicle]

Hello,

I recently started setting up my PiCar-X (Pi Model 4B), but I am experiencing an issue with the front wheels during calibration and operation.

cd ~/picar-x/example
sudo python3 1.cali_servo_motor.py

When I run the calibration command, the front wheels immediately turn all the way to the right and remain stuck in that position.

The same thing happens when I run the code I have shared below to move the car. As soon as the device starts initializing, the front wheels immediately turn to the right and stay at that angle.

cd ~/picar-x/example
sudo python3 3.keyboard_control.py

I am wondering whether I might have installed the servo motor incorrectly. However, I believe I mounted it at the correct angle according to the instructions.

Has anyone experienced a similar issue with the PiCar-X P2 X? Could this be related to the servo calibration, the servo motor installation, or a configuration or software issue?

I would really appreciate any advice or troubleshooting steps you could suggest.

Thank you in advance for your help!

[SunFounder_Moderator]

After reviewing it, it looks like this is an assembly issue — specifically, it appears the steering servo was assembled without being zeroed first.

To fix this, please follow these steps:

Remove the steering servo’s mounting screw, then pull the front wheel off.

Power on the Robot HAT and press the Zero button (servo zeroing).

Plug the steering servo cable into the PWM11 port.

With the front wheel facing straight forward, reinsert the servo arm onto the servo shaft, then tighten the servo screw.

This should realign the steering so the wheels sit straight at the neutral position.

If you run into any issues after following these steps, please feel free to contact us by email and we’ll continue to help.