STEM Participation Days

Last week, the STEM participation days took place. From 13.09 to 15.09, the Fab Lab team was invited by the district of Siegen-Wittgenstein to the front plaza of the district house. Every year in September, around 1,000 children and teenagers from all types of schools and daycare centers take part in a wide variety of STEM offerings for experimenting, experiencing and discovering. The Fab Lab was part of the various research and discovery stations as an extracurricular learning space.

The team had prepared a workshop on the introduction to 3D printing. A total of six groups of students from the eighth grade upwards from secondary schools and grammar schools took part. A small, mobile Fab Lab was created in a tent for this purpose. We brought a total of six of our eight Prusa 3D printers and ten of our laptops.

First there was a short theoretical introduction to basics, design principles, hazards, modeling and slicing. After a short demonstration part, the pupils were allowed to get hands-on: they could create their own key chains in the free software Tinkercad. Once the model was ready, the students transferred them to the slicer, prepared them for 3D printing, and were then able to print their designs on their own. Of course, we were there to help the students with any questions or problems they might have. For example, pendants with initials and names, or objects such as swords and ping-pong bats were created. The students were allowed to take these home at the end of the workshop.

Despite the rain, the sun was shining inside the tent: we were very happy about the engagement and interest of the students and hope we gave them some understanding of 3D printing!

Open University

On May 14, we were represented with a booth at the Open University at the Lower Castle. In our luggage we had a couple of 3D printers, our robotic arm, as well as our augmented reality sandbox.

Spread over the Lower Castle Square, a lot of institutions and study programs and research projects were represented to introduce themselves. We were very pleased that many of you visited us. Sure, the weather was nice and there was an ice cream truck right next to our tent.

At the booth, visitors were able to learn how to use the 3D printer, and there were many interested visitors who were able to go home with their own printed parts. Our robotic arm, has been blithely demonstrating all day how to 3D scan and digitize objects (to then replicate them with the 3D printers, for example). The augmented reality sandbox was particularly well received. You can interactively change a topography of a map with the sand, build mountains and valleys, and then watch the flow of water on the map with a water and rain simulation. A great way to learn about topography and augmented reality.

GAME NIGHT | VOL. I

Harder. Faster. Pilz

On thirst…thursday, July 7th, 7pm: Sandstr. 26 in Siegen!

Dance, game & drink the night away! Play a round of Mario Kart (Switch & SNES) or Street Fighter 2 (SNES) with (or against) us. Let’s celebrate the end of the semester with plenty of drinks, tasty vegetarian & vegan food and good music.

Everybody welcome! We have food and beer, all for free.
No regristration needed.

Additional opening hours for students

In addition to our opening hours for the Open Lab every Wednesday from 14 p.m. to 20 p.m., this summer term we also have times when the Lab is open specifically for students.
As of now, students can also work in the Fab Lab on Tuesdays and Thursdays during the following times:

Tuesdays from 13 p.m. to 16 p.m.

Thursdays from 14 p.m. to 17 p.m.

These extended opening hours are directed towards students of the University of Siegen in order to offer additional times to work on their projects. Individuals not affiliated with the university are welcome to come to the Open Lab on Wednesdays as usual.

The same recommendations apply here as for the Open Lab:

  • no more than 20 guests in the lab
  • 3G recommended (genesen, geimpft, getestet = recovered, vaccinated, tested)
  • the mask is kindly requested to be worn at all times
    (Exception: drinking and eating in certain areas).
first Open Lab held in April on the 6th of April 2022

Reopening of the Fab Lab

Finally, we are back with good news! The Fab Lab will re-open at the beginning of the summer semester. We are thus happy to announce the date for the next Open Lab:Wednesday, April 06.

However, given the still very high number of corona cases, we have a few recommendations for visitors to the Lab:

Within the Lab we recommend to maintain the3G rule(genesen, geimpft, getestet = recovered, vaccinated, tested). Furthermore, it is recommended to wear a mask at all times. Of course, the mask may be removed for drinking, but we would kindly ask you to put it back on immediately afterwards. For this reason, open drinks (e.g. coffee/tea cups) are currently viewed with caution, as experience has shown that these lead to “Kaffeeklatsch” 😉
Instead of eating right at your workplace, we would like to ask you to consume your foodat the open (!) windows in the lobby at Startpunkt to ensure the safety of everyone staying here.

The number of visitors in the Fab Lab is limited to a maximum of 20 guests.

In summary:

  • maximum 20 guests in the lab
  • 3G recommended (genesen, geimpft, getestet = recovered, vaccinated, tested)
  • wearing the mask all the time is kindly requested
    (Exception: drinking and eating in certain areas).
first Open Lab held in April on the 6th of April 2022

Production of a prototype for a bending machine (Master thesis mechanical engineering)

As part of my master’s thesis at the Chair of Micro- and Nanoanalytics in cooperation with the Chair of Forming Technology at the University of Siegen, I developed and subsequently commissioned a bending machine for plastic forming in the scanning electron microscope.

The bending machine will be used to perform three-point bending tests to investigate the crack initiation of bent specimens in order to better utilize materials in bending forming. Forming processes are used in the manufacture of products in many areas of daily life: Cars, aircraft, ships, piping, sheet metal forming and many more.

For a detailed examination of the bending specimens during the bending test, I built the bending machine to fit the scanning electron microscope (SEM). Since there is little space available in a scanning electron microscope, the machine had to be relatively small and light – it fits on the palm of a hand. Initial bending tests in the SEM have already been carried out.

Rapid Prototyping

During the design phase, I used 3D printing as a rapid prototyping process. Compared to machining processes, this method has the advantage of fast production of parts based on CAD models. The first 1:1 scale prototype was designed and 3D printed during a planning and development project, also as part of my studies.

Especially at the beginning of the project, it was important to quickly get a good idea of the real dimensions of the components to be manufactured later. Thanks to the friendly support of the Fab Lab in the person of Fabian Vitt, the required components were printed quickly and without any problems. Thanks to the friendly support of the Fab Lab in the person of Fabian Vitt, the required components were printed quickly and without any problems. In this way, all those present can get a very good picture of the shape and details of the component that will later be manufactured through the 3D printouts. This is less possible with the otherwise often used printed construction drawings. 3D prototyping can lead to new fitting ideas and facilitate the identification of necessary optimizations.

A short animation video of the bending process:
https://lmn.mb.uni-siegen.de/in-situ-em/

A Child’s Book, or: Saving Plastic, Starting 3D Prints New

During the summer semester 2020, there was a printer in the Fab Lab that was constantly cancelled for testing. The printer with the name “Hades” had to serve as a test object for a children’s book. But what does a children’s book have to do with highly experimental, plastic-saving techniques? Let’s lunge a litte bit.

Earlier this summer semester, I decided to develop a children’s book for 3D printers. Together with my fellow student C. Ajiboye, this became a manual that tells a story on one side, one of Ursa, a girl exploring 3D printing through “Learning By Doing.” On the other side, there were explanations of how Ursa finds problems and what solutions it gives for each of them.
But the last page was special:

A WLAN-enabled (ESP32) microcontroller was embedded in this page. This one could feel touches via its touchpins. I then soldered these pins to copper surfaces and hid them under the page. One laser cut later, the copper surfaces could be seen shining through.

Thanks to these surfaces it was now possible to give commands to the ESP32. And thanks to the Octoprint servers, it was then possible to give commands to the printers. Yes, you read that right, this little book has a remote control for a 3D printer built in.

But What is the Point of All This?

Restarting a 3D print is not an easy task, so far there is not a single Octoprint plugin that dares to do this. The result is that when a print fails, which the sensors do not notice, a lot of time, sometimes days, and also up to kilos of plastic are lost. This book was intended to prevent that.

A book has many advantages: it’s quickly at hand, it’s often where you want it, and the software doesn’t change much. It is also lighter than a laptop and thus handier to use. What’s more, you don’t have to boot it up or preconfigure it. The interface is simply there.

But How do You Restart a Print With a Book Now?

A 3D print is stored in machine code. This “code” is written line by line and executed line by line afterwards. So a group of lines represents a layer, because a 3D print is done layer by layer. If a 3D print fails at one point, the commands could be executed again from this point. In the file, as well as in the real print, an exact height is defined for this. You could measure this height, but neither with the eye nor with a ruler you can find it exactly. With the 3D printer itself, on the other hand, you can find the exact height. Like calibrating old 3D prints, you can now use a piece of paper and the tip to determine to within 0.1mm where a print failed. So, with the book in your hand, you move the nozzle exactly over the pressure, lower it very slowly, and try to feel with a piece of paper placed in between when the nozzle touches the pressure.

The printer then knows exactly where this nozzle is located, if it is still referenced. Based on this height, the code is then split, the necessary initial steps are executed and then the printer prints again as if it had never stopped.

I Want This Too

After this semester I found the time to develop this project as a plugin for Octoprint. So you don’t need your own book and you can try it out in the web interface. But ATTENTION! This plugin is highly experimental and has also once caused damage to a 3D printer. I do not make any guarantees or take any responsibility for future damages and advise to always hover with your hand over the emergency switch until the first layer prints again and you are sure that the printer is working on the correct line.

Yours, Gerrit.