This is a belt tensioning device powered by a small 28BYJ-48 stepper motor (dummy not included) winding up a belt to create a certain amount of tension. Can be applied in a broad variety of assemblies where it is crucial to precisely control the amount of tension applied. The original purpose was a very promising medical application for the treatment of muscular insufficiencies. If you have questions about the project and its development, please contact https://www.cgtrader.com/flybuoy61 here on cgtrader. The application works with a belt (e.g. Nylon) with a maximum width of 27mm. I provide files with different tolerances in the size of the center hole that can be used for different printing materials such as PLA, PETG and ABS as well as 2 versions of the shaft. If you need a similar asselmby with different specifications, feel free to contact me for custom solutions.