https://www.youtube.com/watch?v=a9QL7FRAFFg
this video shows our project exactly

Hello,
I started openmodelica 2 weeks ago for my project in High School.
I worked on the electric tooth brush.
I succed to represent the motor and other things but since 4 days I have a problem, I don't know how to transfor a rotational movement in semi rotational movement in 16 degree . Is there possible ?
In fact, in the brush  , after the gear , there is a system rod/crank which tranfor my rotation movement in a rotation of 16 degrees.
Can you help me please. Thank youu