$fn=100;

module aimant (dia,h,dir="U") {
h2 = h / 2;
h4 = h / 4;
if (dir == "U") {
color("red") translate([0,0,-h4]) cylinder(d=dia,h=h2,center=true);
color("blue") translate([0,0,h4]) cylinder(d=dia,h=h2,center=true);
}
if (dir == "D") {
color("blue") translate([0,0,-h4]) cylinder(d=dia,h=h2,center=true);
color("red") translate([0,0,h4]) cylinder(d=dia,h=h2,center=true);
}
if (dir == "R") {
rotate([90,0,0]) {
color("red") translate([0,0,-h4]) cylinder(d=dia,h=h2,center=true);
color("blue") translate([0,0,h4]) cylinder(d=dia,h=h2,center=true);
}
}
if (dir == "L") {
rotate([-90,0,0]) {
color("red") translate([0,0,-h4]) cylinder(d=dia,h=h2,center=true);
color("blue") translate([0,0,h4]) cylinder(d=dia,h=h2,center=true);
}
}
}

module aluminium(d1,d2,ep) {
color("gray") difference() {
cylinder(h=ep,r=d1,center=true);
cylinder(h=ep+0.1,r=d2,center=true);
}
}

aluminium(100,80,5);
for(i=[0:10:360]) {
rotate([0,0,i]) translate([0,90,-8]) aimant(14,6,"U");
rotate([0,0,i]) translate([0,90,8]) aimant(14,6,"D");
rotate([0,0,i]) translate([0,75,0]) aimant(8,6,"L");
}
for(i=[0:6:360]) {
rotate([0,0,i]) translate([0,105,0]) aimant(8,6,"R");
}