angle = 120;
thickness = 4;
diam_offset = 1;
$fn=100;

module arm(inner_radius, angle, thickness){
    rotate_extrude(angle=angle){
        translate([inner_radius+thickness/2,0,0]) square(size=[thickness, thickness], center=true);
    }
}

module grasp(inner_radius, angle, thickness){
    arm(inner_radius, angle, thickness);
    mirror([0, 1, 0]) {
        arm(inner_radius, angle, thickness);
    }
}

grasp(8+diam_offset/2, angle, thickness);
translate([1.5, 25,0]) grasp(6.12+diam_offset/2, angle, thickness);
translate([3, 46,0]) grasp(4.25+diam_offset/2, angle, thickness);

translate([16,23,15-thickness/2])
difference(){
    cube(size=[thickness, 60, 30], center=true);

    translate([0,10,0])
    rotate([0,90,0])
    cylinder(r=2, h=10, center=true);
    translate([0,-10,0])
    rotate([0,90,0])
    cylinder(r=2, h=10, center=true);
}

translate([12, 23, 0])
cube(size=[thickness, 60, 4], center=true);