Katharina Elleke


RECYCLE plastic.     Use BICYCLE as power supply.     RECYCLE in-house.


The main aim of this project is to develop an efficient
bicycle/human-powered version of a plastic shredder…


The project precious plastic enabled and animated people all over the world to recycle plastic waste through designing machines in a way that people can build them with a low budget and little expertise.
Great stuff! To further improve this concept and to make it even more accessible and attractive, I am working on a way to efficiently run the precious plastic shredder with a bicycle (or more).
Many people have already tried to build a bicycle-powered plastic shredder and some of them even worked quite well, but none of them was very productive: All the cyclists pedalled hard in order to crush a small amount of plastic.

My goal is to make it possible to easily crush a good amount of plastic (at least 100kg/day) with cheap and ‘green’ energy, which is independent from the power grid (important for countries like Kenya, where power is not always or not at all available).

… AND to kick-start an in-house recycling system in our faculty.


As a second part of my project I intend to animate the students/professors/visitors of our design faculty in Munich to separate their waste (especially the plastic waste from the general waste) and thereby contribute to an in-house recycling system.
Why? Firstly, for the simple reason to collect plastic for the shredder. But especially I also hope to get people excited about recycling through bringing the recycling process closer to them – and the opportunity to turn the waste into material the designers can use again for their products.

The master plan


  • Build the precious plastic shredder (open-source version) check!
  • Research and gather input about bicycle-/manpowered machines ongoing.
  • Get bicycles, hometrainers etc. as a basis to start with – 2 bicycles, 1 hometrainer: check!
  • Start building, try and error, gather experiences, test out, learn from failures, keep on going, keep on pedalling, crush plastic… but don’t crush your fingers.

In-House Recycling

  • Install separation facilities (bins) in several locations of our faculty – asap.
  • Inform everyone about the topic, the plan, the aims, advantages and opportunities (print, online, talk to people!) – starting now.
  • Collect, clean and sort the plastic – ongoing.
  • Find a place to store the plastic asap.
  • Feed the shredder! Store the crushed plastic.
  • Think of basic tool/machine (and get it!) to make a small (reasonable) product as a demo example and give-away.

This project will be a lot about being in the workshop and finding a mechanical solution (firstly), trying out a lot and learning about plastic types and properties, driving mechanisms, as well as forces and other aspects occuring when working with the combination of plastic, shredder and bicycle.

It will also be an experiment to see if and how you can excite people about topics like plastic recycling, zero waste etc. and see how they react to it and participate in order to be a small part of one solution for the global plastic waste problem in a fun way!
We might be able to set an example for good waste separation and recycling as a faculty and inspire other faculties / universities to do the same 🙂

P.S. More illustrations and photos coming soon.


  1. Sounds great and well-structured, good job! You might also want to add the documentation or better yet “dramatic staging” of the whole thing. What kind of pictures or videos can you imagine that help your project to live beyond the short semester term and our design department?

    1. Very glad to read this positive feedback, thank you!
      Will definitely start to show the progress soon.
      And yap, I’m having the “dramatic staging” in mind. Will try to sketch down and upload my thoughts within the next days.

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