Mechanical Design

Design a machine (mechanism+automation), including the end effector Build the passive parts and operate it manually
Document the group project and your individual contribution

The loop plotter

Our group assignment was to design a plotter. For the plotter’s sheet we wanted to create a loop rotating endlessly.

Designing the paper loop mechanism

My challenge was to design the mechanism of the loop. The design based on a mechanism Ilia ,my group colleague, took apart from a printer. We used two polls and the belt from the given mechanism.

Taking the reuse parts in account I started planning the gears on which the belt will turn. In order to rotate the pols around themselves we used three gears, one for each pole and one for the motor. In additionally we put a fourth wheel for stretching the belt.


We assemble the loop mechanism by locating the belt and then setting the distance between the poles. Measuring the distance allowed us to fix the mechanism on a base surface.

The paper mechanism 3D model file:

download 3dm.File

The machine's files:

files folder

After putting together the plotter we found the following mistakes in our planning:

  1. The holders of the marker weren’t long enough.
  2. We had to set a spring for the tension wheel for maintaining the belt stretch.
  3. The gears width were to tight and caught the belt.
  4. Because we need the marker to move faster and to collaborate with the paper mechanism we will switch to Jens mechanism design.
  5. In the paper mechanism we were missing supports for the pipes holders

Jens mechanism

Note:In hindsight we got to know a software that we could have used for planning the mechanism gears, and we will use for the final design in order to decrease the friction between the belt and the gears.

***Although each one of us had his own mission on the group assignment, we worked as a team all along and supported one another***