Getting in Gear Investigation

Today we started to work with gears and experimenting with gear ratios.

We experimented with making both the driven and driving gears larger. We did this be switching which gear (24t/8t) was attached to the motor. The driving gear is the gear attached to the axle attached directly to the motor, the driven gear is the gear that is attached to the axle attached to the wheel (turned by driving gear). We found that making the driving gear larger than the driven gear speeds up the robot based on the ratio of the teeth on the wheels. However by making the driving gear smaller than the driven gear means that the gear has to rotate multiple times to turn the other gear once. This slows down the robot however adds considerable torque to the robot (torque is basically the power/driving strength behind a motor) .

The highest speed we would be able to achieve with the taskbot NXT model without using gear trains would be with using a gear ratio of 40t to 8t with 8cm diameter wheels.

However, as we came to realize, having a setup with high gear ratios and high angular velocity creates a potentially hazardous situation for the NXT motor and gears. If for whatever reason the robot hits an obstacle and doesn't stop, then the motors multiplied driving force of the gears can bend or mangle parts of the NXT. Having some sort of PANIC! button here would be useful...or perhaps just adding a touch sensor to the front of the robot underneath some sort of ramming shield.