STEM Labs

### Step 1: The Gears in a Single Layer of the V5 Gear Box Build

In every layer of the gearbox, you meshed a 12-tooth gear with a 60-tooth gear. Notice that the 60-tooth gear is on the shaft that turns when you turn the shaft lock plate. When the 60-tooth gear turns, it turns the 12-tooth gear. That means that on this side of the gearbox, the 60-tooth gear is the driving gear and the 12-tooth gear is the driven gear. Locate the three locations in the build where a 60-tooth gear drives a 12-tooth gear. Hint: It matters which shaft you're turning. You can use a Shaft Collar extended to a wheel or another shaft-locked part to make it easier.

Since there are 5 times as many teeth on the larger gear, our gear ratio is 5:1, meaning every 5 turns of the smaller gear, the larger gear will turn 1 time.

### Step 2: Using a Larger Gear as an Input for Increased Speed

Using a 60-tooth gear to drive a 12-tooth gearational speed around an axle. In the example above, we are turning or driving the large gear. For each 1 turn around for the larger, driving gear, the smaller gear has to turn 5 whole times around. This means that the smaller gear will spin 5 times as fast as the larger gear, due to the 5:1 gear ratio. This is known as high gear ratio; the ratio is higher than 1:1.

### Step 3: Using a Smaller Gear as an Input for Increased Torque

Torque is a measure of how hard you turn something about a center point. You can calculate it by multiplying the force of a push by how far away the push is from the center point. Since the teeth of the smaller, driving gear are close to the center, they push with more force for the same amount of torque. At the same time, the teeth of the driven gear are far away from the center point, so the same amount of force creates more torque.

If you have a larger driving gear, the torque you need to apply to the shaft is much higher than if you were driving a smaller gear. Since we can attach multiple gears to the same shaft, we can adjust the amount of force from the same torque, resulting higher torque with each link. The resultant gear ratio from each stage of our V5 Gear Box is 1:5, a low gear ratio. The driving gear will have to turn further to move the driven gear, but it will make the driven gear push harder.

### Step 4: Multiplying Mechanical Advantage

Each stage has a 5:1 gear ratio, so we can multiply them together to make 5x5x5:1x1x1, or 125:1 ratio between input and output shafts. That means that if you turn the high-geared shaft 1 time all the way around, the output shaft will turn 125 times! On the other hand, if you apply some torque to the low-geared shaft, the output shaft will output with a torque 125 times as high, but it will do it very slowly.

Try turning the high geared shaft with no resistance. How quickly does the output shaft turn?

Try turning the low geared shaft while holding the output shaft. Can you stop the output shaft from turning?