STEM Pneumatics

Everything to do with pneumatics

Pneumatics was already being experimented with in the third century BC and the enormous versatility of compressed air was discovered. Using 8 models and 29 experiments, STEM Pneumatics teaches the basics of pneumatics and shows, for example, how compressors, pneumatic valves and cylinders and an exhaust air throttle valve work. The concept is rounded off by the comprehensive lesson plans for teachers.

Number of students

2-4 per kit

Learning objectives

Making the basic principles of pneumatics understandable and sustainable

Time required

Each task contains detailed time information for lesson structuring

Grade level

Secondary grade

About the product

Didactic material

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Topics and learning objectives

Model 1: Functional model - experience compressed air

Topic: Produce compressed air with a self-built pump and learn how it works in a pneumatic cylinder. Controlling a pneumatic cylinder using a valve.
Learning objectives:

Compressed air allows a pneumatic cylinder to extend or retract. However, blocking the exhaust air prevents this, so it must be able to flow out on the other side of the cylinder.

Non-return valves only allow compressed air to pass in one direction and can be used, for example, to build a compressed air pump.

Time required: 45 min
Model 2: Extended functional model - compressor, pressure gauge, exhaust air throttling

Topic: We generate compressed air using an electrically operated compressor, measure the air pressure using a pressure gauge and take a closer look at the throttling of compressed air.
Learning objectives:

Compressors generate compressed air in continuous operation, A pressure gauge is a measuring device for the pressure of air (or gases in general). It provides valuable insights into how pneumatic systems work.

In order to move cylinders slowly, their exhaust air is throttled. Throttling the supply air is inappropriate.

Time required: two task sheets, 45 min each
Model 3: Barrier with single-acting cylinder - Single-acting cylinder, solenoid valve

Topic: We use pneumatics in a self-built barrier. We get to know the "single-acting" cylinder and the electromagnetic valve. In further tasks we will modify the barrier - so ideally the model should remain constructed.
Learning objectives:

To learn about the mode of operation and areas of application of a single-acting cylinder

Establish the connection between electrics and pneumatics via push-button and solenoid valve

Time required: 45 min, more depending on the speed of assembly and willingness to experiment
Model 4: Barrier with double-acting cylinder

Topic: We show how the movement of a double-acting cylinder can be throttled in only one direction or to different degrees in both directions.

Learning objectives:

Effects of connecting a throttle and a non-return valve in parallel

This allows compressed air to be throttled in only one flow direction, while it flows practically freely in the other.

In this way, we can throttle the exhaust air on one side of the cylinder, but leave the supply air unthrottled in the cylinder. We obtain direction-dependent throttling.

Time required: 45 min, if the barrier from the previous task was still in place
Model 5: Vacuum gripper - generating and working with negative pressure

Topic: We generate air pressure that is lower than that of the ambient air and use this in a suction gripper.
Learning objectives:

A mechanically operated cylinder, as in the home-made hand pump, can generate not only positive pressure but also negative pressure at the other connection.

With this and a suitable flexible suction cup, light parts with a smooth surface can be held, lifted and moved.

Time required: 45 min for construction and thematic tasks, more depending on the implementation of the optional tasks
Model 6: Electropneumatic air motor

Topics: We construct a compressed air motor that works in a similar way to a steam engine.
Learning objectives:

In the functional model of the air motor, the combination of several disciplines leads to success: pneumatics, electrics and mechanics/kinematics.

Only the correct interaction of all sub-areas leads to a solution.

Time required: 45 min
Model 7: Scissor lift tables - pneumatic lifting platform

Topic: We construct a lifting platform - a so-called "scissor lift" - and have it pneumatically driven.
Learning objectives:

The mechanics of the scissor lift and the care required for precise construction,

To increase the achievable force by pairing two pneumatic cylinders in parallel,

the increase in the achievable sliding distance by placing two pneumatic cylinders in series

Time required: 90 min
Model 8: Project model - negative pressure backlash

Topic: This model represents pneumatics in the context of a slightly more complex model - a pneumatic positioning unit that can also be used as a clearance.
Learning objectives:

Design techniques from mechanical engineering

Conversion of a linear movement into a rotary movement

Suitable supply of compressed air to a rotating machine part

Time required: This model is structurally complex and will take several units of e.g. 45 minutes.

Information material

Pneumatics is the name given to the technology used to control and carry out operations in machines using compressed air. Just as with pressurized oil in hydraulic cylinders of large excavators and other construction machinery, large forces and fast movements can also be achieved with compressed air. This offers a whole range of advantages - especially in the children's room and classroom:

Pneumatics is an easy-to-understand and extremely illustrative technology - you can see what moves and you can feel how different levels of pressure result in different levels of force.
Pneumatic cylinders always exert the same force at the same pressure, regardless of how far they are extended. This makes it very easy, for example, to hold a workpiece with a constant force without damaging it with excessive force.
Pneumatic cylinders can be used to perform very fast movements.
Purely pneumatic controls are also possible through the use of valves.
As no sparks are produced (as can be the case with electrical switching), pneumatic systems are also suitable for handling flammable materials (e.g. in filling systems).
Unlike leaking oil in hydraulics, escaping compressed air is not an environmental problem.

For these reasons, pneumatics can be found in countless industrial applications for processing workpieces, filling beverages, packaging, gripping and handling parts and much more.

Pneumatics has a surprisingly long tradition: as early as the third century BC, the Greek mathematician and inventor Ctesibius was already working with compressed air and the machines it made possible. His first pneumatic machine was a pump for lifting water. This was followed by compressed air-based clocks, catapults and organs.

The enormous versatility of compressed air became known and pneumatics was therefore used more and more. Steam engines, steam locomotives, diving with compressed air, painting, airbrush techniques, compressed air sirens, speed measurement with ram jets on airplanes - all of this is part of pneumatics and shows how useful and variable this relatively simple technology can be used.

Today, it is hard to imagine everyday life without pneumatics. It serves countless purposes, from inflating a balloon to the pneumatic hammer in road construction, the easy-to-hold pneumatic impact drill in the household, the suction of air before food is welded in and large industrial plants. A wide field!

Pneumatics is the branch of compressed air technology that deals with the performance of work using compressed air (typically in pneumatic cylinders) and the control of machines designed for this purpose (via valves). This can be divided into the following areas:

Compressed air generation supplies normal ambient air in compressed form. This is achieved by compressors that draw in air, compress it in a pump and discharge it into compressed air lines (hoses or pipes). Low-pressure pneumatics work in the range of approx. 100 mbar to 1 bar overpressure; for higher forces, around 6 bar overpressure is usually used as standard.
In compressed air treatment, the air is cleaned (e.g. filtered) and, if necessary, enriched with a fine oil mist using atomizers, which is used to continuously lubricate moving parts such as valves and cylinders.
Hoses, pipes, T-pieces and the like are used to distribute the compressed air.
They are controlled by valves that can be actuated manually (by an operator), mechanically (by a moving machine part) or pneumatically (by the compressed air signal from another valve). There are a variety of valves for switching a signal on or off (i.e. pressurizing with compressed air or venting), for time delays and for signal storage. Throttles regulate the strength of an air flow (so that a cylinder moves in or out slowly).
Pneumatic actuators are usually pneumatic cylinders. They consist of an essentially closed tube, which is divided on the inside by a tight-fitting disk. The cylinder rod (the piston) sits on the disk. By feeding compressed air into one of the two cylinder halves (and discharging the exhaust air from the other), the disk and thus the cylinder piston can be moved. Cylinders exist in many designs, but there are also other actuators such as pneumatically controlled counters.

Another interesting area of pneumatics is fluidics: switching and controlling with flowing media (gases such as air or liquids). The special feature of this variant is that fluidic valves for logic circuits do not require any moving parts, but instead perform their function solely by cleverly shaping flow channels. It is not the pressure that is the essential signal, but the flow of the medium. With pneumatic fluidics, this works with a pressure of just 100 mbar, requires no oil for lubrication and allows the valves to clean themselves due to the high flow velocity. Only when large forces are required at the end of the control system are the fluidic signals converted into standard pneumatic or electrical signals.
Pneumatics touches on the physical fields of mechanics, kinematics and thermodynamics (compressed air gets warm), fluid mechanics and the mathematical field of logic in logic circuits in pneumatic control systems and therefore Boolean algebra.

The fischertechnik compressor is small and quiet, but powerful. It is operated with 9 V DC voltage and delivers approx. 1 bar pressure and sufficient throughput to operate a wide range of functional models.
The pneumatic tank stores compressed air. It is the pneumatic counterpart to the capacitor in the electronics.
Hoses that are easy to cut with scissors, T-pieces for distributing compressed air to several hoses and plugs for sealing connections ensure that compressed air is available in the right places.
The pressure gauge is a measuring device for air pressure. It helps to make pneumatic processes even easier to understand.

The fischertechnik manual valve is a "4/3-way valve" - it contains four connections for supply air, exhaust air and two outlets for cylinders and has three switching positions. This allows a cylinder to be retracted, extended or held in a given position, for example.
The solenoid valve allows a pneumatic valve to be switched electrically. This connection can be used to create other types of machine control systems - right up to computer-controlled pneumatic machines.
Different pneumatic cylinders do the work: Double-acting cylinders are actively moved in both directions (extension and retraction) using compressed air. Single-acting cy linders have a built-in return spring. They are extended by compressed air and automatically return to the home position by the spring as soon as the compressed air is released.

The valves also include the throttle, which allows compressed air to pass through at an adjustable rate. Only then does a pneumatic cylinder retract or extend at the desired speed, or does a volume gradually fill with compressed air. It corresponds to the resistance in the electronics.
The non-return valve only allows compressed air to pass in one direction. This is used for self-construction of a compressed air source, but it also allows a cylinder to work quickly in one direction and only throttled in the other. This is the pneumatic counterpart to the diode in electronics.
Of course, all of this fits perfectly into the fischertechnik system, so that not only the basic functions of pneumatics are represented, but robust and realistic functional models of machines can be produced.