Using VEX GO Wheels, Gears, and Pulleys

Diagram of all of the Wheel, Gear, and Pulley pieces in the VEX GO Kit.

The VEX GO build system is a fun and easy way to allow students in grades three to five to explore the principles of motion. Its flexibility and function can also be used in higher grades.

Diagram illustrating the mechanics of distance and force using two circular VEX GO pieces. The Blue Wheel is larger than the Green Pulley piece, so it will travel a greater distance when it spins but will also require more force to do so.

This article will introduce you to parts which will allow your VEX GO projects to move.

These parts include:

As you build projects with these parts there is a key idea to keep in mind. It takes a force to move a distance. A larger wheel, a larger gear, or a larger pulley will travel a longer distance every time they make one complete turn, but this will require more force. A smaller wheel, a smaller gear, or a smaller pulley will travel a shorter distance, but this will require less force.


Wheels

Diagram of all of the Wheel pieces in the VEX GO Kit.

The VEX GO system has three types of wheels.

These include:

  • The Blue Wheel.
  • The Gray Wheel.
  • The Tire.

Blue Wheel

Diagram of the Blue Wheel piece, illustrating that it has a 3 by 3 grid of round holes. The center round hole is intended to fit the wheel's axle.

The Blue Wheel has eight attachment holes to attach other parts to the wheel and it has a center round hole which will allow the wheel to spin freely on a pin or shaft.

Gray Wheel

Diagram of the Gray Wheel piece, illustrating that it has a 3 by 3 grid of holes. All of the holes are round except for the center hole, which is square and is intended to fit the wheel's axle.

The Gray Wheel has eight attachment holes to attach other parts to the wheel and it has a square center hole. The square hole will allow a square pin/shaft to be inserted and allow for a power transfer to force the wheel to spin.

Tire

Diagram of the Tire piece being attached to the outside edge of a Green Pulley piece to create a wheel. The Green Pulley piece has a single square hole in its center that is intended to fit the pulley's axle.

The Tire can be combined with a Green Pulley to create a small wheel. The Green Pulley has a square center hole that will allow a square pin/shaft to be inserted and allow for a power transfer to force the pulley to spin.

Diagram of the GO Code Base robot, with arrows labeling its two types of wheels. Gray Wheel pieces transfer power to drive the robot, while Blue Wheel pieces roll freely and do not transfer power.

The Code Base project provides a very good example of how the wheels work. The center round hole of the project’s Blue Wheels allows the wheels to freely roll. The center square holes of the Gray Wheels allows the motors to transfer their power to the shafts which will force the Code Base to move.


Gears

Diagram of all of the Gear pieces in the VEX GO Kit. The teeth count of each Gear piece is shown, with the Red having 8 teeth, the Green having 16 teeth, the Blue having 24 teeth, and the Pink having 24 teeth.

Gears are very useful parts. Gears can be used to transfer power from one to another. Gears can be combined to “gear up” an assembly and this will make the assembly move faster, but it will not be able to exert as much force. Gears can be combined to “gear down” an assembly and this will make the assembly move slower, but it will be able to exert more force.

To determine how a gear system will “gear up” or “gear down'', it is important to know the number of teeth on a gear. You can find this out by picking one tooth on a gear and then counting the teeth around the gear back to that tooth.

The VEX GO system has four different gears. Three of these gears have a square center hole that will allow a square pin/shaft to be inserted and allow for a power transfer to force the gear/shaft to spin.

The gears in the VEX GO system include:

  • The Red Gear.
  • The Green Gear.
  • The Blue Gear.
  • The Pink Gear.

Red Gear

Diagram of the Red Gear piece, illustrating that it has a single square hole in its center that is intended to fit the gear's axle.

The Red Gear has eight teeth and a center square hole.

Green Gear

Diagram of the Green Gear piece, illustrating that it has a single square hole in its center that is intended to fit the gear's axle.

The Green Gear has 16 teeth and a center square hole.

Blue Gear

Diagram of the Blue Gear piece, illustrating that it has 5 holes total. All of the holes are round except for the center hole, which is square and is intended to fit the wheel's axle.

The Blue Gear has 24 teeth. It has four attachment holes to attach other parts to the gear and a square center hole.

Pink Gear

Diagram of the Pink Gear piece, illustrating that it has 5 round holes. The center hole is round and is intended to fit the wheel's axle.

The Pink Gear has 24 teeth and four attachment holes. Its center hole is round and will allow the gear to spin freely on a shaft or pin.

Some important ideas to understand about gears are:

  • Power transfer.
  • Spin direction.
  • Gearing up.
  • Gearing down.

Power Transfer

Diagram of the Motorized Super Car build, with the two connected Gears on its side labeled. The Green Gear on the left is the Driving Gear that is applying power, and the Green Gear on the right is the Driven Gear that is tranferring the power.

Power transfer can occur between two assembled gears. The gear which has power applied to it (known as the driving gear) will transfer its power to the next gear (known as the driven gear).

Spin Direction

Diagram of the Motorized Super Car build, with the two connected Gears on its side highlighted. The driving Green Gear on the left is labeled as spinning clockwise, and the driven Green Gear on the right is labeled as spinning counterclockwise.

When two gears are assembled, the driven gear will spin in the opposite direction as the driving gear wheel is spinning. For example, if the driving gear is spinning in a clockwise direction, the driven gear will spin counterclockwise.

Gearing Up

Diagram of the Motorized Super Car build, with the two connected Gears on its side labeled. The larger, driving Blue Gear on the left is labeled to spin once, and the smaller, driven Red Gear on the right is labeled to spin three times.

Gearing up occurs when two gears are assembled and the driving gear has more teeth than the driven gear. For example, what if the driving gear has 24 teeth (Blue Gear) and the driven gear has eight teeth (Red Gear)?

When the driving gear spins its 24 teeth around once, it will force the driven gear with eight teeth to be turned three complete times. The driven gear will spin three times faster; however, the gear will only be able to apply 1/3 the force.

Gearing Down

Diagram of the Motorized Super Car build, with the two connected Gears on its side labeled. The smaller, driving Red Gear on the left is labeled to spin once, and the larger, driven Blue Gear on the right is labeled to spin one third of a rotation.

Gearing down occurs when the driving gear has fewer teeth than the driven gear. For example, what would happen if the driving gear has eight teeth (Red Gear) and the driven gear has 24 teeth (Blue Gear)?

When the driving gear’s eight teeth have made one complete turn, the 24-tooth driven gear will have only turned 1/3 of a turn (eight teeth). The driven gear will be spinning at 1/3 the speed; however, it will be able to apply three times the force.

Diagram of the Super Car build, with the three connected Gears labeled. The first is a driving Blue Gear that has a label that reads Driving gear with Red Square Beam attached. The second is a Blue Gear that has a label that reads Power transfer. The third is a driven Red Gear that has a label that reads Gearing up, driving Blue Gear with driven Red Gear.

The Supercar build includes some very good examples of how gears can be used.

The force to move the car starts from the energy of a stretched rubber band. The attachment holes on a Blue Gear allows a Red Square Beam to be attached with standoffs to help the rubber band move the Blue Gear.

A second Blue Gear provides a power transfer.

A gearing up occurs when the second Blue Gear drives the Red Gear on the shaft of the Gray Wheel making the Supercar move!


Pulleys

Diagram of the Orange Pulley piece, illustrating that it has 5 holes total. All of the holes are round except for the center hole, which is square and is intended to fit the pulley's axle.

Pulleys are very versatile parts. Some of the things they can be used for include:

  • Wheels.
  • Pulley Systems.
  • Decorations.

The VEX GO system has two sizes of pulleys. Both of the pulleys have a square center hole that allows a square pin/shaft to be inserted and allow for a power transfer to force the pulley to spin. The pulleys include:

  • The smaller Green Pulley which has been mentioned earlier in this article and can be combined with the Tire to create a small wheel.
  • The larger Orange Pulley which has four round attachment holes in order to attach other parts to the pulley.

Pulley Systems

Diagram illustrating the mechanics of pulley systems using Green Pulley and Rope pieces. The diagram demonstrates that a rope attached to a pulley will spin in opposite directions on either side. To pull an object attached on the left up, the right side of the rope must be pulled down. The diagram also demonstrates that a pulley with a rope attached to an anchor on one side will have twice the mechanical advantage, as each side of the rope now supports one half of the weight.

The Pulleys in the VEX GO system can be combined with the Ropes to create a pulley system. A pulley system can either change the direction of a force applied to a rope or increase its mechanical advantage.

Decorations

Close-up of the face on a VEX GO Crawler build, where Green Gear pieces are used as decorative eyes on the robot's face.

Pulleys, gears, and wheels are fun parts. Use your imagination to create eyes, heads, or any other things for your projects.

Wheels, gears, and pulleys are important parts for your VEX GO system. They will bring motion to your projects. Motion will bring your imagination into reality!

For more information, help, and tips, check out the many resources at VEX Professional Development Plus

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