difference()
{
    union()
    {
        difference()
        {

        hull()
        {
         cylinder(d=10,h=12,$fn=100);   
         translate([87,0,0]) cylinder(d=10,h=12,$fn=100);  
         translate([87,32,0]) cylinder(d=10,h=12,$fn=100);  
         translate([0,32,0]) cylinder(d=10,h=12,$fn=100);  
        }  

        translate([1,1,-1]) hull()
        {
         cylinder(d=10,h=12,$fn=100);   
         translate([85,0,0]) cylinder(d=10,h=12,$fn=100);  
         translate([85,30,0]) cylinder(d=10,h=12,$fn=100);  
         translate([0,30,0]) cylinder(d=10,h=12,$fn=100);  
        }
    }    

    translate([6+40,6+9.5,8]) cylinder(d=28,h=3,$fn=100);  
}

 
    
   translate([-10,9,0])  cube([10,10,11]);
    
   translate([-5+8,-5+14,0]) cube([24,14,50]);

   translate([6+40,6+10,7]) cylinder(d2=27, d1=22,h=5,$fn=100);

   translate([-5+79-14,-5+13,0]) cube([19,19,50]);

}