Strong Pneumatics

Discover the power of compressed air through play!

To enable children to get to know and try out the topic of pneumatics, fischertechnik offers the pneumatics toy “Strong Pneumatics”, which with its realistic models and components enables quick and easy understanding and promotes technical imagination. 6 different models guarantee exciting adventures for young designers.

Compressed air is an indispensable part of everyday life. You probably encounter her in different forms every day. This can start with your morning breakfast egg, which may have been packed using pneumatic suction cups.

The word pneumatic comes from the Greek word “pneuma” and means “air”. Pneumatics is primarily about generating movements with air and performing mechanical work. You can drive almost anything with compressed air. It can be used as an alternative to muscle power or any other energy such as electricity, water, hydraulic oil or wind power.

Today, pneumatics are still everywhere in everyday life. Whether it’s inflating an air balloon, using a pneumatic hammer in road construction, diving with compressed air, painting, airbrush techniques, compressed air sirens, speed measurement with air jets on aircraft or large industrial systems - pneumatics are used everywhere!

What are the advantages of pneumatics?

The advantages of pneumatics are that …

compressed air can be stored
Compressed air can be transported over long distances through pipes and hoses or in suitable containers
compressed air is clean and does not cause contamination
Movements can be carried out quickly with compressed air
Many movements can be realised with pneumatic cylinders without complex mechanics
it is explosion-proof

We would like to explain these advantages and many other interesting information to you with the Strong Pneumatics module. We also want to show you how the pneumatic components work. To do this, we explain the individual components step by step and show how they work. The modular system also contains numerous model examples that illustrate how pneumatics can be used.

A little bit of history

Already in the third century BC, the Greek mathematician and inventor Ktesibios dealt with compressed air and the exciting possibilities it offers. He developed the first compressed-air-powered machines, such as a catapult that threw balls and spears with compressed air.

A very well-known compressed air system is that of Heron von Alexandria, who used the altar fire to generate compressed air and thus opened the large temple doors like a ghost’s hand. The heat from the altar fire heated the air in a pressure vessel that was half filled with water. When you heat air, it expands and the air pressure increases. The expanding air required more space and pressed the water from the pressure tank into a water tank, which lowered due to the increase in weight and thus opened the doors.

Pneumatics have been used as drive and control technology in industry since the beginning of the 20th century. In the construction and agricultural machinery industry, the topic of pneumatics is used to drive hammers and drills, for example. Suction and pressure pneumatics are also used in conveying technology, e.g. in grain mills for suctioning grain and conveying flour. We even find pneumatics in the music industry, for example in organ manufacturing. In a piano, a self-playing piano, the keys are pneumatically controlled. Pneumatic applications can be found in the automotive industry, the textile and food industry, electrical engineering, even in space, and in many other areas of everyday life.

Information material and tasks

A pneumatic system consists of five subsystems.

Compressed air supply
Compressed air distribution
Compressed air preparation
Movement generation by pneumatic cylinder
Control of movement by valves

Compressed air can be generated by a compressor or air pump and stored in compressed air cylinders and other pressure vessels.

The diaphragm pump as a compressor

Your Fischertechnik compressor is a diaphragm pump. It provides you with the necessary compressed air to control each model. In industry, we talk about the source of compressed air.

How it operates:
A diaphragm pump consists of two chambers separated by a diaphragm, hence the name of the component. In one, the elastic membrane is moved up and down by a piston and an eccentric. During the downward stroke, the diaphragm is pulled backwards and air is drawn into the second chamber via the inlet valve. On the upward stroke of the piston, the diaphragm pushes the air out of the pump head via the outlet valve.

Please note that:
The overpressure generated by the compressor is approx. 0.7 to 0.8 bar. The diaphragm pump is maintenance-free. It is important that you use a 9V alkaline battery to power the compressor. Of course, the fischertechnik Accu Set is even better suited, as it has significantly more power than the 9 V block, lasts much longer and can be recharged again and again.

Compressed air distribution
The blue hoses are the means of transporting compressed air. They transport the compressed air to where it is needed. You can route the air lines from the compressor to the valves and cylinders.

Compressed air preparation
In order for pneumatic components to function correctly in industry, it is important that the compressed air is treated accordingly. To do this, the air must be filtered, cooled, dehumidified and, if present, the oil removed. However, this is not necessary for Strong Pneumatics modular models.

Pneumatic cylinders

To create movements with air, we use pneumatic cylinders. A basic distinction is made between “single-acting” and “double-acting” cylinders. The Strong Pneumatics module contains two pneumatic cylinders of different sizes with the same “double-acting” function.

The blue piston rod is movable and the cylinder is sealed. If you blow air into the cylinder through one of the two hose connections, the piston rod moves. If you blow in on the opposite side, the piston moves back. The piston can therefore work actively in both directions of movement. The port through which the piston rod is extended is called port A, the port for retracting is called port B. Since the piston rod of the cylinder can be
extended and retracted with air, the cylinder is called a “double-acting cylinder”. To see this in practice, carry out a test.

Experiment:

Attach a piece of the blue tube to the A port of a cylinder and connect it to the tube connector of the compressor already connected to the battery holder. When you turn on the compressor, the piston rod extends. As itis a double-acting cylinder, the piston retracts when you connect the hose to port B and use the compressor to supply air again.

However, as already mentioned, there are also “single-acting cylinders”. With these cylinders, the piston rod can only move in one direction. A spring is often used to move in the other direction.

To show that you can compress air, perform another attempt.

Experiment:

Now extend the piston of the cylinder again by reconnecting your blue hose, which is connected to the compressor, to port An and applying compressed air. After the piston rod is extended, switch the hose connection to B while holding the A connection closed with your finger.

Please note that:

The piston rod can only be pushed in slightly. Do you know why?

Explanatory note:

As you have blocked the air port A with your finger, the air inside the cylinder cannot escape. But the air can be compressed. For this reason, the piston rod was pushed in a little. The more air is compressed, the higher the pressure in the cylinder. This pressure can be measured with a pressure gauge. The unit for pressure is “bar” or “Pascal”. The height of the pressure can also be calculated. The formula for calculating the pressure level is:

Pressure = Force/Area or in short p = F/A

With the formula, you can see that the amount of pressure depends on how much force is applied to the round surface in the cylinder.

As you have seen in your experiments, it is quite cumbersometo reconnect the hoses over and over again. This work will be done by valves, which will be explained to you in detail in the next chapter.

Valves

In pneumatics, a valve has the task of controlling the air flow to the pneumatic cylinder so that the cylinder either extends or retracts. A valve can be operated mechanically, electrically, pneumatically or manually.
Manual valves are included in the Strong Pneumatics kit. These valves each have four ports:

The compressed air is supplied from the compressed air reservoir via the centre connection P. The left or right port (An or B) directs the compressed air to port An or port B of the cylinder. The port R on the lower side of the valve is used for venting. This allows the air that returns from the cylinder to escape. To test the function of the valve, carry out the following test.

Experiment:
Connect the compressor already connected to the battery holder to one of your valves. To do this, take a piece of the blue hose and attach it to the hose connection of the compressor and to the connection P of the valve. Leave the other connections free. Set the blue switch on the manual valve to the middle position and switch on the compressor.

Please note that:
Nothing happens at all.

Explanatory note:
When you set the switch on the hand valve to the middle position, the ports are closed and no air will pass through.

Next attempt:
Now turn the valve switch to the right and turn the compressor on again. Meanwhile, always tap with a finger on the free ports An and B. Do the same if you have turned the valve switch to the left.

Please note that:
The air always flows through port A when you turn the blue knob on the valve to the right and through port B when you turn the knob to the left.

Explanatory note:
The illustration helps you understand how the air flows through the valve when you turn the knobs in the different directions. The blue line here is the compressed air flowing through the valve. The black lines show you how the air flows back from the cylinder.

The valve therefore has four connections and three switching positions (centre - left - right). For this reason, the valve is referred to as a 4/3-way valve in the pneumatic system.

Exhaust damper

Have you ever stood on the water hose in the garden or kinked it? If so, you have probably noticed that suddenly less water comes out of the hose. But why is that? Due to the kink in the hose, the water has less space to flow, so it is restricted and thus slower. The same happens in pneumatics when the air in the means of transport, in our case the blue hose, becomes constricted and has less space to penetrate.
You may be wondering why we should want to do this at all?
By throttling the air, the different movements can be carried out more slowly and in a more controlled manner.

Industrially used pneumatics are usually operated at a pressure between 6 and 8 bar. This allows pneumatic cylinders to extend very powerfully and, above all, very quickly if required. A strong but slow and controlled movement is often required. A movement that is too fast could endanger machine parts, workpieces to be handled or even people.
In order to move the cylinders slowly, the compressed air is throttled. We let less air flow through a hose or pipe at a time by simply narrowing the cross-section of the pipe.

Experiment:
Build the functional model and perform the following tests:

Do not restrict the exhaust air by screwing the blue screw into the housing just enough to avoid squeezing the hose. Observe how quickly the cylinder extends or retracts.
Now throttle the exhaust air more and more by gradually screwing in the blue screw. Look at the cylinder again. What do you notice?

You can see that the exhaust throttle helps you to adjust the extending or retracting speed of the cylinder.

Now we want to take a closer look at what we have just learned on self-built models, which are often pneumatically executed in reality. To do this, we build the models one after the other and do one or two attempts each to understand even better how everything works.

Scissor lift table

Lifting tables are used as an aid to lift heavy loads. They are mainly used for loading workpieces. Such a lift consists of a base frame on which the load can be placed. The scissors of the same length are attached to this. These scissors move in the centre of an axle, which is also attached to the base frame.

In order to understand the construction of the scissor lift table correctly, assemble the first model as described in the assembly instructions.

Scissor lift table - Task 1:

After connecting the compressor and laying the hoses as described in the assembly instructions, turn the blue knob on the valve to the right. What’s going on? The scissor lift table moves upwards. Why do you say that?

Since you have connected the hoses in your model so that the compressed air is routed from port An of your valve to port An of the cylinder, the piston of the cylinder extends. This extension moves the centre axis of the lifting table to the right, which raises the scissors and pushes them upwards.

You can lower the lift again by turning the valve to the left side and the piston of the cylinder is retracted.

Scissor lift table - Task 2:
But what happens now if the scissor lift table has to carry a larger load, such as a cup or a book? Can you still raise the lift? Try to find out how much weight you can put on the lift so that it can still lift the weight. Enter the values in the next table.

Objective:	Weight in grammes	Lift moves up Yes/No

Scissor lift table - Task 3:
Do you have an idea how the lift can lift even heavier weights? Consider how to increase the lifting capacity of the scissor lift table.

Solution:
If the power of a cylinder is not enough to lift heavier loads, add a second pneumatic cylinder. Install the second cylinder into the lift as shown in the assembly instructions and connect it according to the hose diagram shown there. Repeat Scissor Lift Table - Exercise 2 with your new model and analyse what has changed.

In the chapter “Pneumatic cylinders”, you learned that the acting force depends on the pressure and the surface on which the pressure acts (round surface in the cylinder). Since the pressure that the compressor creates is constant, we need to increase the area on which the pressure acts. We achieve this by using two cylinders. This allows the pressure to act on the double surface (two round cylinder surfaces). This also doubles the force and thus the weight you can lift. This means that we can generate more power through more surface area.

Clamping fixture

Do you have a vice at home? Then you can use it to clamp the parts you want to machine. File, drill or simply press together. Actually very practical if you don't have to crank for so long. You can see that we need a pneumatic solution.

Clamping device - Task 1:
Design and build your own pneumatic clamping device with a cylinder (no assembly instructions). Do you have an idea how this could work? If not, you can find our suggestion in the building instructions.
Once you’ve assembled the model, you’ve probably already turned on the compressor and turned the valve switch.

Switch to the right = Clamp
Switch in middle position = hold voltage
Switch to the left = release tension

Once you have switched off the compressor again, you can use exercise 2 to professionally clamp a workpiece (module 30) in your pneumatic clamping device.

Clamping device - Task 2:

Compressor is switched off.

Turn the valve switch to the centre position
Insert the workpiece.
Switching on the compressor
Turn valve switch to the right
Turn the valve switch to the centre position
Switch off the compressor

Your workpiece is now pneumatically clamped for machining.
You will ask: “Why move the switch to the centre position?”
Every pneumatic connection and line loses a little air. In the centre position, the line to the compressor is disconnected and the loss of compressed air from this side is reduced.

In order to fully open the tensioner on the first model, you had to turn the compressor back on. That’s awkward - don't you think? In the first model, your compressor without an air accumulator was connected directly to the middle port of the hand valve. In our next model, we will now install two air reservoirs. For the following model, this means that the compressed air from the compressor is not directed directly to the manual valve, but to the other cylinders. Consequently, these cylinders are filled with compressed air and store it.

Now install two cylinders as air reservoirs in your simple model. If you don't know exactly how to install the accumulators in your model, see your building instructions.

After converting the model, insert your workpiece (module) into the clamping device. Turn the manual valve switch to the middle position. Turn on the compressor and watch the pistons in the cylinder move up as they fill with compressed air. If the compressor makes a steady buzzing sound, sufficient pressure has been built up and you can turn it off again in.
Now comes the moment for which the conversion was worthwhile.

Clamping device - Task 3:
The valve switch is in the centre position, the accumulator is filled and the compressor is switched off.

Inserting the workpiece
Turn valve switch to the right
Turn valve switch to centre position -> workpiece is clamped
To unwind, simply turn the valve switch to the left

Please note that:
Have you noticed the difference from the first model? The cylinder was completely retracted during decompression without switching the compressor on again. You can even clamp and unclamp your workpiece a second time. Do you know why?

Explanatory note:
Your compressor can store additional air volume in the two cylinders and dispense it to the tensioning cylinder as needed.
All these topics and experiments have now brought you closer to the world of pneumatics. As you can see, the pneumatics have a lot to offer and are very interesting. In the next chapter, you can turn to the game models of the Strong Pneumatics module.

In addition to the functional models, the Strong Pneumatics construction kit contains three other models with exciting play functions. These are realistic models of front loaders, tree trunk grabs and double gyroscopes. Again, reinstall the compressor into your model and connect it to your pneumatic valves and cylinders. You can then use the manual valves to control the grapple arms of your log grapple by hand, for example. The exhaust throttle also contributes to a realistic image by allowing the speed of the movements to be controlled.

In reality, however, functions like these are not performed pneumatically, but with the help of hydraulics. Hydraulics use oil instead of air to move the cylinders. Unlike air, oil cannot be compressed, which means that significantly higher forces can be transmitted. However, the power of the pneumatics is completely sufficient for your Strong Pneumatics game models. It is also particularly clean, fast, reliable and, above all, exciting.

Have fun building and playing!

Malfunction

Probable Cause

Remedy

Movement does not work

Exhaust air restricted too much

Open the screw from the exhaust throttle, i.e. unscrew

The compressor runs normally but the actuated pneumatic cylinder moves very slowly or not at all

Exhaust air restricted too much

Open the screw from the exhaust throttle, i.e. unscrew

Compressor and all cylinders are OK, but one cylinder does not extend

Exhaust air restricted too much

Open the screw from the exhaust throttle, i.e. unscrew

Cylinder extends and retracts very quickly despite the built-in exhaust throttle

Exhaust air restriction too low
Exhaust throttle connected to wrong manual valve

Close the screw from the exhaust throttle, i.e. screw it in
Check the connection of the exhaust throttle using the hose diagram

Compressor is not running

Battery is missing
Battery holder is not switched on
Strands are not inserted correctly

9 Use V-Block battery or Accu Set
Check the wires

Movement does not work

Several valves are in position An or B (too much air is flowing through the valves)

Return all valves to the centre position (locked position) after each movement

The compressor runs normally but the actuated pneumatic cylinder moves very slowly or not at all

Manual valve leaking

Test: Move the valve to the centre position. Consecutively all

pressurise the three connections and place them in the water

is displayed. If many bubbles rise, the valve is leaking

Pneumatic cylinder leaking

Test: Pressurise both connections one after the other

and hold it in the water. If many bubbles rise

the cylinder is leaking

Replace manual valve
Replace pneumatic cylinder

Compressor and all cylinders are OK, but one cylinder does not extend

Hose blocked at one point
Hose kinked

Test: Connect each hose individually to the compressor

and test whether the compressed air is routed through.

This can be heard and felt

Replace clogged hose if necessary
Make sure that there are no kinks in the hose

Strong Pneumatics​

Information material and tasks​

Scissor lift table

Clamping fixture

Strong Pneumatics

Information material and tasks