/*
    - All measurements are in mm unless otherwise stated.
    
    - The variable for material width is "mat_width", change this depending on the material used.
*/

    module body()
     {
        intersection()
        {
            offset(r=+15) offset(delta=-15)
            square(50, center=true);
        }
    }
           
     module slots()
     {
        make_ring_of(radius = 44, count = 4)
        translate([22,22,0])
        {
            rotate([0,0,45])
            {
                square([6,30], center=true);
            }
        }
    }
    
   difference()
    {
        
        body(){}
        slots(){}

        
    }
  
    
    module make_ring_of(radius, count)
    {
        for (a = [0 : count - 1]) 
            {
                angle = a * 360 / count;
                translate(radius * [sin(angle), -cos(angle), 0])
                rotate([0, 0, angle])
                children();
            }
    }