Part I — VEX IQ Fundamentals · Chapter 5
Building the Drivetrain
Get the drivetrain wrong and nothing else on the robot matters.
Your drivetrain decides how your robot moves. Get it wrong and nothing else on the robot matters, because the robot cannot get where it needs to go.
Pick Your Drive Type
IQ gives you three real options. Default to tank drive unless the season specifically rewards sideways movement.
Speed vs Torque
Every gear ratio trades speed for torque. Build your ratio around your robot's final weight, not its weight on day one.
Ratios and Motor Count
Gear ratio and motor count are not separate decisions, they work together. Pick your ratio for the robot's final weight, then pick your motor count to support that ratio, not the other way around. Torque-heavy ratios like 4:3 rarely need four motors, they already carry the power. Speed-heavy ratios like 2.5:1 and 3:1 are the ones that start asking for four motors, since more speed multiplies the load on fewer motors.
Two identical robots, one on 2-motor drive, one on 4-motor drive, pushed against resistance to show the torque difference live.
Try the gear ratio calculator
Play with ratio and motor count yourself and see the speed/torque tradeoff instantly.
Try it yourself