The motors of my picar x wheels are not going at the same speed

Robotic kit for Raspberry Pi
1

The motors of my picar x wheels are not going at the same speed and the difference between the two motors is huge (something like 2x) it makes the robot unusable. Is there a fix for that ?
Thanks

2

To better assist you, we kindly suggest the following:

  1. Provide a Video: Could you please share a video of the issue you are experiencing? This will help us better understand the problem and provide a more accurate solution.
  2. Code Modification: Have you made any modifications to the software code? If so, please let us know the details.
  3. Motor Behavior: When running all the motor-related examples, do the motors consistently operate at inconsistent speeds?

Providing this information will help us diagnose the issue more effectively.

3

I have the same problem. Left and right motor are not running at the same speed. Consequence is that the car cannot be steered well, since this interferes with the steering servo. Is there a solution to this?

4

We suggest you provide a video of the issue, as it will help us analyze and resolve the problem more effectively. Additionally, please try swapping the left and right motor connections to determine if the slower performance is due to the specific motor or if it’s an issue with the connections.

5

I switched the connenctions with no effect.

6

I also made a video. However, I cannot attach it (Sorry, new users can not upload attachments.). How to proceed?

7

You can upload it on OneDrive and share the link.

8

“C:\Users\Tobias\OneDrive\Picarx_different_motor_speed.mov”

9

This link doesn’t work. You need to share from your OneDrive account on website.

11

Direction motor of front wheel don’t seem to be well calibrated and centered.

12

As Weirdyguy mentioned, it seems the issue may be due to the front wheel servo not being properly centered, causing a misalignment with the rear wheels. I recommend removing the front wheel servo, resetting it to zero, and then recalibrating.

The servo angle range is -90° to 90°, with factory settings being random, which can lead to confusion if assembled incorrectly. To avoid issues, all servo angles should be set to 0° before installation.

Here’s a quick guide:

  1. Insert the servo arm onto the servo shaft and gently rotate the arm to see the servo’s movement.
  2. Run the servo zeroing code:

cd ~/picar-x/examples
sudo python3 servo_zeroing.py

  1. Connect the servo wire to port P11; you should see the arm rotate to the 0° position.
  2. Remove the servo arm while keeping the wire connected to P11, and do not turn off the power. Continue assembling as per the instructions.

You can also follow our assembly video here: Assembly Video.

13

Steering servo is not the problem. In the video, I am steering the steering servo via the app control on my phone. The problem is that the vehicle is unable to respond to the steering angle because of the different motos speed of left and right motor. This is clearly visible in the video, towards the end.

14

The question is how to calibrate the two motors separately in order to achieve the same motor speed?

15

Could you please run the motors of the PiCar-X while suspended to check their working status? If there is a significant speed difference between the two motors, we will arrange to send you new motors. However, if the difference is minor, it is considered normal.

Please provide a video for further confirmation.

17

Could you please swap the connections of the left and right motors and test them again? We would like to see if the left motor still runs at a slower speed.

Thank you for your cooperation! You can contact us at service@sunfounder.com,we will send you a motor.