This project took me a long time... There are errors, but they can be fixed... If you want to try and print... Assembly is somewhat difficult... and you need axes with a diameter of 3 mm... and drops of... Glue

So far, I have not been able to manufacture the brush....but I am thinking of the thin plastic threads resulting from printing

Some explanation .....glue the - MCC  Gear B - to the brush before assembly and use - MCC  BP -  to secure the axes  ..... glue - MCC  Tire LG -to the - MCC  Gear L - make sure it rotates freely before assembling the axle and second tire

The parts are many.....but the assembly method can be understood.....I imagine....and it does not require support