50:1 is the lowest gear ratio (fastest speed) of micro metal gearmotor that we recommend using with our Zumo robots. If you are using a lower gear ratio, the motors will have less torque, and turning could be an issue. The turning issue gets worse if the Zumo is loaded with more mass, which is common when competing in mini-sumo.
One way to increase the speed of your Zumo’s motors is to increase the voltage supplied to them. The Zumo 32U4 runs off of four AA batteries (which is nominally 6V); this voltage gets passed to the onboard DRV8838 motor driver, which has a maximum voltage of 11V. You should be able to safely use a 2S LiPo, which has a voltage as high as 8.4V when fully charged. Using a 3S LiPo, which has a voltage as high as 12.6V when fully charged, would be too much for the drivers.
Each I/O pin on the Zumo 32U4 is already being used for some other purpose, so you might need to disable or disconnect some of the other features of the Zumo 32U4 to add your QTR-1RC sensors. You can read more about how to free up I/O pins under the “Adding electronics” section of the Zumo 32U4’s user’s guide, which can be found under the Resources tab of its product page.
Hi, I have 2x Zumo 32U4 with the 100:1 motors. I want to buy the 50:1 HP or even 30:1 HP motors for a fast line following competition. Can you please point me to the correct ones?
You can find all of our micro metal gearmotors here. We have two versions of dual-shaft high power (HP) 6V micro metal gearmotors: a version featuring carbon brushes and a version with precious metal brushes. The two versions have identical performance, except we expect the micro metal gearmotors with carbon brushes to have a longer lifetime than the versions with precious metal brushes. Our fully-assembled Zumo 32U4’s use motors with precious metal brushes.
If you want to modify your Zumo 32U4 to use a 50:1 HP gearmotor, use either the version with precious metal brushes or the version with carbon brushes.
And if you want to modify your Zumo 32U4 to use a 30:1 HP gearmotor, use either the version with precious metal brushes or the version with carbon brushes.