# Mechanisms

## Simple Gear Train

### Simple Gear Train "A" 1. Build the gear train out of VEX GO parts as shown.

• What is the relationship of the input shaft compared to the output shaft

• Is the speed increased, decreased, or constant?

• What is the gear ratio?

• Is the direction of rotation the same?

### Simple Gear Train "B" 1. Build the gear train out of VEX GO parts as shown.

• What is the relationship of the input shaft compared to the output shaft

• If the blue gear is the input, is the speed increased, decreased, or constant?

• If the green gear is the input, is the speed increased, decreased, or constant?

• What is the gear ratio?

### Simple Gear with Idler 1. Build the gear train out of VEX GO parts as shown.

• What is the relationship of the input shaft compared to the output shaft

• Is the speed increased, decreased, or constant?

• What is the gear ratio?

• What does the idler gear change?

## Bevel Gear Assembly  1. Build the bevel gear assembly out of VEX GO parts as shown above.

• What is the angle of the input shaft compared to the output shaft?

• Is speed increased, decreased, or constant?

• Is torque increased, decreased, or constant?

• What is the gear ratio?

• Is the flow of power reversible? (Can you make the input shaft turn by turning the output shaft?)

3. List an example where this mechanism might be used. A helpful search term is bevel gear.

## Belt Drive ### Belt Drive "A"

1. Build the belt drive out of VEX GO parts as shown.

• What is the relationship of the input shaft compared to the output shaft

• Is the speed increased, decreased, or constant?

• What is the gear ratio?

• Is the direction of rotation the same?

3. List one benefit of using a belt instead of meshing gears. ### Belt Drive "B"

1. Build the belt drive out of VEX GO parts as shown.

• If the orange pulley is the input, is the speed increased, decreased, or constant?

• If the green pulley is the input, is the speed increased, decreased, or constant?

• What is the gear ratio? ### Belt Drive "C"

1. Build the belt drive out of VEX GO parts as shown.

• Is the speed increased, decreased, or constant?

• What does the crossed belt change?

## Crank and Slider 1. Build the crank and slider out of VEX GO parts as shown.

2. Label the crank and slide

• The input to this system is what type of motion?
(rotary, reciprocating, or linear)

• The output of this system is what type of motion?

• How far does the slider move with each revolution of the crank?

• If the diameter of the crank gear were increased, would the slider move a shorter or longer distance?

• Is the flow of power reversible? (i.e., can you make the crank gear continuously rotate by pushing the slider?)

4. List an example of where this mechanism might be used. A helpful search term is crank and slider.

## Cam and Follower 1. Build the cam and follower out of VEX GO parts as shown.

2. Label the cam and follower

• What is the type of input movement? (rotary, reciprocating, or linear)

• What is the type of output movement?

• How many times does the follower move up and down with one revolution of the crank?

• Is the flow of power reversible, i.e., can you make the cam turn by pushing the follower?

• Is the direction of travel reversible, i.e., does the mechanism still work if the crank is turned in the opposite direction?

4. List an example where this mechanism might be used. A helpful search term is camshaft.

## Rack and Pinion (kind of) 1. Build the cam and follower out of VEX GO parts as shown.

2. Label the cam and follower

• What is the type of input movement?

• What is the type of output movement?

• Describe which part is the rack gear and which is the pinion gear.

• If the diameter of the pinion gear were increased, would the rack move a shorter or longer distance with one revolution of the axle?

• Is the flow of power reversible, i.e., can you make the input shaft turn by sliding the rack gear?

• Is the direction of travel reversible, i.e., does the mechanism still work if the input shaft is turned in the opposite direction?

4. List an example where this mechanism might be used. A helpful search term is "rack and pinion".

## Scissor Lift   1. Build the scissor lift out of VEX GO parts as shown.

• What is the type of input movement?

• What is the type of output movement?

• Describe one benefit of this mechanism.

• Is the flow of power reversible, i.e., can you make the input shaft turn by sliding the output?

• Is the direction of travel reversible, i.e., does the mechanism still work if the input shaft is turned in the opposite direction?

3. List an example where this mechanism might be used. A helpful search term is "scissor lift".

## Wiper  1. Build the wiper mechanism out of VEX GO parts as shown.