$fn = 50;
/* eprouvette de traction - version 2 */
// trop compliqué
/*difference() {
    translate([0,0,35]) cube([5,20,70], center = true); {
        translate([0,0,8]) rotate([0,90,0]) cylinder(h = 12, r = 2.5, center = true);
        translate([0,0,62]) rotate([0,90,0]) cylinder(h = 12, r = 2.5, center = true);
        translate([0,-15,35]) cube([7,25,30], center = true);
        translate([0,15,35]) cube([7,25,30], center = true);
        translate([0,-10,45]) rotate([0,90,0]) cylinder(h = 12, r = 7, center = true);
        translate([0,10,45]) rotate([0,90,0]) cylinder(h = 12, r = 7, center = true);
    }
}
*/

L = 70;
module forme() {
    union() {
        offset(r = -2) offset(delta = 2){
            translate([0,0]) square([4,L], center = true);
            translate([0,L/2]) square([15,15], center = true);
            translate([0,-L/2]) square([15,15], center = true);
        }
    }
}

linear_extrude(4) difference() {
    forme();
    translate([0,L/2]) circle(d = 3);
    translate([0,-L/2]) circle(d = 3);
}