Lemonade factory

built by children and teenagers from Romania

The association "Children's Aid Romania Lipova" (Fundatia Ajutati Copiii Lipova) has introduced fischertechnik in some children's homes in Romania. The children had a lot of fun and created a hammer-like model.

How did the idea of a lemonade factory come about?

Over several years, the association has built many different models in several children's houses. This showed the enormous age-related flexibility of the learning toy. It quickly became clear that it made sense to divide the toys according to age. More complex constructions such as a "Haribo Automat" were created with interested young people.
In order to convince even more young people, the idea of the lemonade factory was born. The idea was very attractive, because it was not only about simulating a process, but also about producing something useful. The first preliminary work was carried out in Romania (conveyor belt, gripper robot), the construction of the filling station and the final assembly had to be carried out in Germany due to difficulties in material procurement.

How does the lemonade factory work?

Procedure

The factory consists of single modules which are controlled by 4 microcontrollers (Arduino UNO):
- Cash box for Lei and Euro
- Bottle magazine for 6 bottles
- 4-axis gripper robot
- conveyor
- Filling station with pump
- Lid magazine for 6 bottle lids with screw thread
- Gripper arm for lid with vacuum suction bell and motor for screw rotation

actuators
The factory is equipped with eight fischertechnik DC motors, two Sevos, one stepper motor, one compressor, as well as a cash register for coins and banknotes (one ft motor and one LDR light barrier with basic module and relay module).

Robots: Two fischertechnik motors (up/down, left/right), two servos (forward and backward/open and close pliers)

Bottle magazine : A fischertechnik engine
Conveyor belt : Ein fischertechnik Motor

Filling station: One fischertechnik motor forward/backward, one stepper motor for 90° rotation (filling function/lid), one mini motor for screw rotation (forward/backward), one pump for liquids, one compressed air cylinder (arm lifting/lowering) with two electric valves, three compressed air cylinders for vacuum with two electric valves, one fischertechnik compressor.

Lid magazine: A fischertechnik motor

Control

The DC motors and solenoid valves are controlled via power transistors or H-bridge circuits (for forward and return) which are controlled by the microcontrollers. The servos are controlled via the servo program contained in the Arduino library (#include< Servo.h>), the stepper motor via the stepper motor program contained in the library (#include< Stepper.h>).
The dead centres in upward and downward movements, forward and backward movements as well as the rotary movement of the gripping robot are detected by FT sensors. A drop-out delay (discrete via relays, capacitors and resistors) generates the input pulse required by the Arduino (duration 0.2 sec.), since the input of the microcontroller is blocked when there is continuous contact and no new commands are accepted.
The control concept of the microcontrollers works serially (one after the other) and is based on the "Statemaschine" program, which can also be called up from the library.

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