Exploring Leverage and Simple Machines with the T-Bot Hydraulic Arm
The best physical science education tools aren’t just fun and interesting to use. They also encourage kids to think about what they’ve learned and seek out real-world connections long after the tools have been put back on the shelf. That’s just one reason why, among all our exciting and thought-provoking STEAM learning kits, the T-Bot Hydraulic Arm is one of the most popular.
After constructing the T-Bot Hydraulic Arm, kids can pick up and move objects using hydraulics. Rather than simply reading about hydraulics and levers in a book, this hands-on experience gives them a clear understanding of how automation and heavy machinery work. It also opens kids’ eyes to the dozens of objects they see every day that use levers. That includes doors, hammers, wheelbarrows, brooms, tweezers, and even their own arms!
How do levers work?
Imagine a heavy weight is sitting on the ground. If you try to lift it straight up, you might find it very difficult to move. And if it’s too heavy, you could really hurt yourself!
Levers are simple machines that make heavy objects easier to move by providing what’s known as “mechanical advantage”. This means they reduce the force required to move an object.
The simplest and most familiar example of a lever is a seesaw. It consists of a length of wood balanced on a fulcrum, the point against which a lever rotates.
If you put the heavy weight on one side of the seesaw very close to the fulcrum and push down on the other side, you’ll find that the weight is much easier to move. The farther you are from the fulcrum, the more mechanical advantage you’ll have. But there’s a catch…
Let’s say you’re applying pressure to the seesaw at a distance three times farther from the fulcrum than that of the weight. In this case, you’ll need to push your end of the seesaw down by three feet to lift the weight by just one. The farther you are from the fulcrum, the easier it will be to lift the weight, but the further you’ll need to move your point of pressure.
3 classes of levers
Different types of levers fall into one of three classes. Each class has a different arrangement that provides a different benefit in effort and movement.
The seesaw we talked about earlier is a type of Class 1 lever. It consists of a fulcrum positioned between the effort and the load.
Another type of Class 1 lever is a claw hammer that’s being used to pull out a nail. In this case:
- The nail is the load
- The point where the hammer rocks is the fulcrum
- Effort is applied downward in the direction of the hammer’s face on the handle
When you remove a nail using a claw hammer, you need to move the handle quite far, but the sturdy nail is easy to remove.
A good example of a Class 2 lever is a wheelbarrow. Here, the fulcrum is at the far end (the wheel) and the load is positioned between the fulcrum and the effort (the handles).
Even though the load is on the same side of the fulcrum as the effort, it will always be closer to the fulcrum. Therefore, it still provides a mechanical advantage.
The simplest type of Class 3 lever is a broom used for sweeping. In this case, the hand you use to steady the broom is the fulcrum.
When using a broom, the effort you put into moving the handle is much closer to the fulcrum that the load of the brush. This is the opposite of a Class 1 lever, and as you might expect makes the load harder to move.
So why would we ever use a Class 3 lever? Well, even though the load is harder to move, it also moves much further when we apply effort. In the case of a broom, this increased distance lets you sweep up more dust more quickly.
How does the T-Bot Hydraulic Arm teach kids about levers?
When kids build the T-Bot Hydraulic Arm, they aren’t limited to just one arrangement. There are actually four arrangements to choose from, giving kids a deeper understanding of levers and simple machines!
This is a type of Class 3 lever. Here, effort is applied between the fulcrum and the load. So you lose your mechanical advantage but increase the distance traveled.
When the arm is extended straight out in this arrangement, the far point of the syringe is positioned behind the fulcrum relative to the load. But because the syringe can rotate, the effort is transferred by the plunger up through the triangular connectors and into the last section of the arm. Since this is between the fulcrum and the load-bearing gripper, Lever B is also a Class 3 lever.
Lever C is another example of a Class 3 lever. It has a few positions that you might think are the fulcrum. But actually, it’s the point from which the gripper pivots. The gripper itself is the load.
The effort transfers down from the syringe and through the connector. This then applies force between the fulcrum and the end of the gripper. Lever C is actually two parallel, identical levers that operate using the same input force.
Levers A, B, and C are just that – levers. But Lever D is actually a simple machine, a modified lever called a wheel and axle. In this case:
- The fulcrum is identical to the axel (the point at which the whole robot rotates)
- Effort is applied at the outside of the rotating wheel
- The load, while tricky to locate, is actually found where the robot connects to the wheel on the same side of the fulcrum as the effort
This makes Lever D a type of Class 2 lever.
Explore a whole new world of movement with the T-Bot Hydraulic Arm
As well as discovering the science and engineering behind hydraulic movement, using the T-Bot Hydraulic Arm helps kids better understand the world around them. After using it, they’ll start seeing levers everywhere they go, allowing them to apply their learning to real-world problem solving.
The T-Bot Hydraulic Arm can be easily built and dismantled over and over again so that your kids can explore a wide range of levers. This gives them deeper insight into the role of hydraulics and machines in industry, construction, and transportation. These fundamental skills prepare them to overcome future challenges and thrive both academically and in life.
Order your T-Bot Hydraulic Arm now to introduce your kids to the wonderful world of hydraulics, levers, and engineering!