Summary

Enjoy!

Source code for OpenScad:

//CODE....
$fn=100;
down(lenght=50);
up(lenght=50);

module down(lenght){
difference(){
cube([lenght,10,8]);
translate([lenght-6,-1,12]) rotate([0,45,0]) cube([10,12,10]);
translate([-9,-1,12]) rotate([0,45,0]) cube([10,12,10]);

translate([-20,5,4]) rotate([45,0,0]) cube([lenght+10,10,10]);
translate([lenght-10,2.4,0]) cube([11,5.2,10]);
translate([lenght-4,10,4]) rotate([90,0,0]) cylinder(d=5.2, h=10 );
translate([lenght-11,2.4,0]) cube([8,5.2,10]);
translate([-1,3,0])cube([5,4,2]);
}

}

module up(lenght)
{
translate([2*lenght-8,0,8]) rotate([0,180,0]) union(){

translate([lenght-4,10,4]) rotate([90,0,0]) cylinder(d=4.8, h=10 );
translate([lenght-6.5,2.6,1]) cube([5,4.8,9.2]);
translate([lenght-11,2.6,4]) cube([5,4.8,6.2]);

translate([-0.2,0,0.2]) intersection(){
cube([lenght,10,8]);
translate([-20,5,4]) rotate([45,0,0]) cube([lenght+10,10,10]);
}

translate([-0.3,0,8.2]) cube([lenght-8,10,2]);
translate([-3.3,0,0.1]) cube([3,10,10.1]);

translate([-0.6,3.5,1.9]) rotate([-90,0,0]) linear_extrude(3)
polygon([[0,0],[1.5,0],[1.5,1],[0,1.8]]);

}
}