$fn=100;
difference(){
  translate([0,0,12.5]) cube(size=[30,30,25], center=true);
    
//  minkowski(){
//    hull(){
//      translate([0,0,13]) cube(size =[12,10,26], center=true);
//      translate([0,0,-2]) cube([46,10,1], center=true);
//    } 
    //cylinder (2, center=true);
//  }  

//  //---------------------------------------------------------------------------------------------
//  translate([0,-7.3,3]) cube(size=[60,2.2,6], center=true);        
//  translate([0, 7.3,3]) cube(size=[60,2.2,6], center=true);        
//  translate([0,-13.1,3]) cube(size=[60,2.2,6], center=true);       
//  translate([0, 13.1,3]) cube(size=[60,2.2,6], center=true);       //ridges for alu profile 
//  translate([0,-18.6,3]) cube(size=[60,2.2,6], center=true);       
//  translate([0, 18.6,3]) cube(size=[60,2.2,6], center=true);       
//  translate([0,-5,5]) cube(size=[60,3,2], center=true);              
//  translate([0, 5,5]) cube(size=[60,3,2], center=true);            
//  //---------------------------------------------------------------------------------------------
//  translate([12,12,12]) cylinder(r=1.25,h=12, center=true);
//  translate([12,-12,12]) cylinder(r=1.25,h=12, center=true);      //mountholes fan 
//  translate([-12,12,12]) cylinder(r=1.25,h=12, center=true);
//  translate([-12,-12,12]) cylinder(r=1.25,h=12, center=true);
//  //---------------------------------------------------------------------------------------------
//  translate([0,-28.75,7]) cube(size=[10,2.5,14], center=true);   //cross bow support  
//  translate([0, 28.75,7]) cube(size=[10,2.5,14], center=true);            
//  //---------------------------------------------------------------------------------------------
//  //translate([0,0,0]) cube(size=[46,14,8], center=true);            //trim of fan rect  
//  translate([2.5,-25,1.25]) cube(size=[5,11,2.5], center=true);
//  translate([2.5, 25,1.25]) cube(size=[5,11,2.5], center=true);
//  minkowski() {
//    translate([0,0,10.75]) cube(size=[30.5,30.5,3.5], center=true);           
//    cylinder(3);
//  }    
}
$fn=50;
minkowski()
{
  cube([10,10,10]);
  cylinder(1);
}