x_size = 20;           // horizontal outer size of the aquarium pedestal. 
y_size = 20;           // 
thickness = 10;         // thickness of the pad bellow aquarium. hairs lenght is 12mm. 
rim_height = 7;        // height of upper rim for fixing the aquarium in position.

mount_hole = 3.7;
clear = 0.175;


// aquarium pad

difference () {
    intersection() {
        union(){    // bottom part with rim/fixing pin
                rotate([0,0,45])
                    cube([x_size, y_size ,thickness], center = true);
                translate ([sqrt(pow(x_size,2) + pow(x_size,2))/4, sqrt(pow(x_size,2) + pow(x_size,2))/4, thickness/2 + rim_height/2])
                    cube([sqrt(pow(x_size,2) + pow(x_size,2))/2, sqrt(pow(x_size,2) + pow(x_size,2))/2, rim_height], center = true);

            };

        rotate([0,0,45])
                cube([x_size, y_size ,4*thickness], center = true); // cut out half of top tip 
    }
    cylinder (h = thickness + rim_height, r= mount_hole, $fn=20);   // hole for screw head    
    translate ([0, 0, -thickness])      // hole for the screw 
        cylinder (h = thickness + rim_height, r= mount_hole/2, $fn=20);
    
    
    rotate([0,0,-45])       // hole for top part mounting nut
        translate ([ 0, -x_size/3, thickness/3])    
            cube([6, 3, thickness], center = true);

    rotate([90,0,-45])      // hole for top part mounting screw.
        translate ([ 0, 1.8, 0])    
            cylinder (h = thickness + rim_height, r= mount_hole/2, $fn=20);

}




//translate ([0, 0, thickness])    // separate two parts

/*rotate([180,0,0])       // hole for top part mounting nut


//Top part

union () {

wall_thickness = 3;

rotate([0,0,45])
translate ([-wall_thickness, 0, 0]) 

    difference () {
        translate ([wall_thickness/2, 0, thickness/2 + 1.5*wall_thickness])    
                cube([x_size - wall_thickness, y_size , wall_thickness ], center = true);

        rotate([0,0,-45])
            translate ([sqrt(pow(x_size,2) + pow(x_size,2))/4, sqrt(pow(x_size,2) + pow(x_size,2))/4 ,  rim_height])
                cube([sqrt(pow(x_size,2) + pow(x_size,2))/2, sqrt(pow(x_size,2) + pow(x_size,2))/2, 2*rim_height], center = true);
    };    

rotate([0,0,45])
translate ([-8.3, 0, 0]) 

    difference () {
        translate ([8.3/2, 0, thickness/2 + wall_thickness/2])    
                cube([x_size - 8.3, y_size , wall_thickness ], center = true);

        rotate([0,0,-45])
            translate ([sqrt(pow(x_size,2) + pow(x_size,2))/4, sqrt(pow(x_size,2) + pow(x_size,2))/4 ,  rim_height])
                cube([sqrt(pow(x_size,2) + pow(x_size,2))/2, sqrt(pow(x_size,2) + pow(x_size,2))/2, rim_height], center = true);
    };      

    
rotate([0,0,-45])

    difference  () {

        translate ([0, -y_size/2 - wall_thickness/2 , 1.25 * wall_thickness])    
            cube([y_size, wall_thickness , thickness + 1.5*wall_thickness ], center = true);
        
        
            rotate([90,0,0])
                translate ([-0.5/2, 0, rim_height/3])    
                    minkowski() {
                        cube([0.5,3.1,10]);
                        cylinder(r=1.5,h=1,$fn=50);
                    }
            }


    
}