Trilobot - One motor slower

Hey guys!
I just received my new and shiny Trilobot. Finished the assembly tutorial, cloned the repo, and started with the examples.
Well, I was surprised, when I started up my first example
follow_straight.py
It was not going straight, it was doing a circle to the right ;) Stopped it, and written a simple loop with
tbot.forward(speed=1.0)
Same result. Well… created a different loop with:
tbot.set_left_speed(1.0)
tbot.set_right_speed(1.0)
Simmilar. So, I modifeid it to:
tbot.set_left_speed(0.7)
tbot.set_right_speed(1.0)
Slower on the left. Changed to 0.9 - Well, it was almost straight, but still going to the right a little. Changed to 0.8… and it was going little to the left.
Anything I can do to calibrate it ? Some simple fix? Or I had a bad luck, and had a faulty motor ?

I have attached it to RPI4, 2GB model, and rpi camera v2. Anker powerbank, or wall chager - same result.

Ok, I did some additional checking. With speed 0.7.
When I detached both dc motors, I had 3,5V on every cable going from the main board. But when I measured the voltage on working dc motors, there was 3,5V on the faster one, and 2.2V on the slower one.
I switched the motors, and now he is doing circle to the left.
Any ideas ? I’m an absolute noob in that area.

It sounds like an issue with the motor controller not the motor. Somethings not working right with the H Bridge.
I’d disassemble it and reassemble it, a pain, but if its just a bad connection somewhere it should fix it.
Other than that you can contact Pimoroni by e-mail via the following link. I’d put a link to this thread in the e-mail.
Contact Us for Raspberry Pi Technical Support – Pimoroni

@krondar, have you heard anything further on this? My Trilobot has a slight skew to the right; I’ve not experimented enough as you have, to know by how much. Would appreciate any feedback you’ve received on this.

I was actually intending to examine the code and see if there’s a way to add a “calibration” offset. Though I suspect it isn’t abnormal for motors to be slightly different, further experience could change that belief.

Hey @CosmicFurFace. Well, depends how ‘slight’ its skewing. My Trilobot was litterally taking a turn to the right, or left. I have sent an email to Pimoroni, at the same time I have posted this subject, and after few emails, and a small video I have recorded - they have sent me a replacement motor.
I received this motor today, and just replaced it. Now, on a flat surface (table for instance), he is really going straight, and not turning or skewing.
Can you maybe post a small video? We could compare it with my Trilo :)