A set of 11 gears with the following characteristics:

Gear module 2mm

• Inner hole 4mm
• Number of teeth variable from 10 to 20
• Thickness 10mm

To correctly couple them, the axis of the couple you consider, shall be placed at a distance given by:

axis_distance [mm] = number_of_teeth_grear_1 + number_of_teeth_gear_2

Note: this formula is valid only for this specific set of gears with module 2.