scale(10){
difference()
{
    square([43,43],true);
    
    translate([20.75,0])
    {
       square([1.5,29],true); 
    }
    translate([-20.75,0])
    {
       square([1.5,29],true); 
    }
    
    
    
    
    translate([-20.75,20])
    {
       square([1.5,3],true); 
    }
   translate([-20.75,-20])
    {
       square([1.5,3],true); 
    }
    
    translate([20.75,20])
    {
       square([1.5,3],true); 
    }
   translate([20.75,-20])
    {
       square([1.5,3],true); 
    }
    
}}