use <MCAD/gears.scad>
$fn = 100;  // Smooth rendering
    translate([3, 11, 0])

  rotate ([0,0,360*$t])
spur_gear(5, 20, 20, 10, pressure_angle=20, helix_angle=0, optimized=false);
    translate([120, 0, 0])

  rotate ([0,0,-360*$t])
spur_gear(6, 30, 20, 10, pressure_angle=20, helix_angle=0, optimized=false);
    //
    //rotate([0, 0, $t *  360 ]) 
 //translate ([100,500,0])
 //planetary_gear(10, 10, 20, 3, 50, 50, 20, pressure_angle=20, helix_angle=0, together_built=true, optimized=true);
 //spur_gear(modul, tooth_number, width, bore, pressure_angle=20, helix_angle=0, optimized=true)