Modkit Bug

Ran into an interesting bug in Modkit, and it took me a bit to track down exactly what was happening.

  1. I was using a “Drivetrain”
  2. Program was:
    A) Turn LEFT 10 degrees
    B) Turn LEFT
    C) Wait 1
    D) Stop

The robot would turn LEFT a bit, then turn RIGHT for 1 second.

The problem was caused by having the gear ratio set to 1:-1 (something I did when trying to reverse the motors, before I saw the checkboxes)

When I changed the gear ratio to 1:1, the robot would turn the same direction for both turns (as expected from the program)

Honestly, I’m not sure which direction it turns, only that with the gear ratio set 1:-1, the two “Turn Left” commands cause it to turn different directions.


Hi Steve,

Yes, we have been able to confirm that setting a negative gear ratio in the Drivetrain block causes unexpected behavior in the Drivetrain turning blocks. Modkit is currently working on a fix for this issue now.


  • Art