Pupils can complete their compulsory school internship in the MINT School Lab at the h_da. In January 2022, there were - under strict corona rules - 8 students from the 9th grade of the Viktoriaschule Darmstadt. Jaouad summed up what they particularly liked: "I thought it was great that there was no fixed schedule, that we could decide for ourselves what we wanted to build and test, and that everything was quite flexible." Jule and Lara added: "We were allowed to try things out freely and work completely independently." But of course, the equipment and its proper operation had to be explained first. To this Tom, who was particularly enthusiastic about the 3D simulations on the computer, said that it was sometimes a "pretty slow start until everything was explained and you were finally allowed to begin."
And which experiments excited the students the most? Hannes and Jannis Finn: "We only knew 3D printers from youtube videos. We think it's great that we were able to try it out for ourselves here. You don't have the opportunity to do that otherwise. Who already has such devices?" Another favorite for Daniel was the robot solar car.
Exemplary work from previous student internships:
- a contribution by Jaeyoung and Katharina (Gymnasium Oberursel) -
As part of our internship at Darmstadt University of Applied Sciences, we looked at 3D printing, specifically two processes:
- Filament 3D printing by material extrusion
- UV resin 3D printing
In the filament 3D printing process, the printer draws a plastic filament thread into the print head and heats it to allow liquid material to flow into the print area. First, the first layer of material is applied directly to the printing plate by XY movement of the print head. The subsequent layers are further distributed and built up in this way on the body of the printed object. In the process, so-called support structures are also printed, which play a very important role in stabilizing geometry overhangs. Depending on the printed object, they can be removed or built into the printed object.
In UV resin 3D printing, unlike filament, the print platform is mounted "overhead" at the top of the print area and the print object is printed by moving it in a corresponding Z motion from top to bottom. By using a resin bath, the print object hardens and becomes solid while being exposed to UV light with a wavelength in the range of 400nm.
When setting up for printing, the support layer (infill...) should be set appropriately to the printed object, otherwise it will be difficult to remove and the actual object could be destroyed in the process.
In our project, we used both methods. With the resin method, it was more difficult to remove the support structures compared to the filament method. We made a self-designed artificial tree, a building and a pen holder.
This three-wheeled car comes from a kit of the company freenove.com. The (single) rear wheel is rigidly mounted. The two front wheels each have a DC motor whose running speed is controlled by the controller. However, the steering is done by a steering linkage on the front axle, which is controlled by an encoder motor. A swivel arm can be used to aim the mini-cam, which transmits a continuous video signal.
The mechanical parts made of plastic, metal and rubber are included in the kit and are easy to assemble. Two DC motors and three encoder motors are used as drives. In addition, the car is equipped with a buzzer and a large RGB LED to "(light) horn". As a sensor you can connect either the Mini-Cam or an ultrasonic sensor.
A Raspberry Pi with an additional hardware shield is mounted on the car. The shield "helps" the Raspberry Pi to communicate with the sensors and actuators, among other things it provides more electrical power to run the motors. A battery is mounted under the car to provide power to the hardware when the car is running.
When the car is driving, the wired connections for the Raspberry Pi's keyboard, mouse and monitor can no longer be used. In this case, the controller is connected via WLAN to either a remote PC or a smartphone (via an app):
The software and programming
If you are dealing with this kit and the Raspberry Pi for the first time, you can first use the included software programs and apps. In the next step, you can create your own control programs in the Python programming language and test them on the device.