// Mål og skriv inn diameter på kula i millimeter:
kulediameter = 16.0; // mm 

difference ()
{
cylinder($fn = 4, $fa = 3, $fs = 2, h = 20, r1 = 10, r2 = 10, center = false);
translate ([0,0,17]) sphere ($fn = 100, d=kulediameter+0.6); // Diameter på hullet til kula
translate ([0,0,18]) cylinder($fn = 40, $fs = 2, h = 4, r1 = 7.5, r2 = 7.5, center = false);
}
difference ()
{
translate ([-15.0,-15,0]) cube(size = [30, 30, 2], center = false); 
translate ([-11.5,-11.5,-1]) cylinder($fn = 10, h = 7, r1 = 2.0, r2 = 2.0, center = false); 
translate ([-11.5,11.5,-1]) cylinder($fn = 10, h = 7, r1 = 2.0, r2 = 2.0, center = false); 
translate ([11.5,-11.5,-1]) cylinder($fn = 10, h = 7, r1 = 2.0, r2 = 2.0, center = false);
translate ([11.5,11.5,-1]) cylinder($fn = 10, h = 7, r1 = 2.0, r2 = 2.0, center = false);  
}

translate ([0,11,0]) cylinder($fn = 10, h = 20, r1 = 2, r2 = 2, center = false); 
translate ([11,0,0]) cylinder($fn = 10, h = 20, r1 = 2, r2 = 2, center = false); 
translate ([0,-11,0]) cylinder($fn = 10, h = 20, r1 = 2, r2 = 2, center = false); 
translate ([-11,0,0]) cylinder($fn = 10, h = 20, r1 = 2, r2 = 2, center = false); 
//color("white",1.0) translate ([0,0,17]) sphere ($fn = 200, d=kulediameter);