3d Printer roller cart

module carrito()

{
$fn = 90;
rotate(270, [0, 1, 0])
translate ([12.5,0,0])

difference (){

//main cube;
translate ([-12.5,-55,-2])
cube ([12.5,110,52]);

//hueco pa caja de bolas IZQUIERDA;
translate ([-13,-40,35])
rotate(90, [0, 1, 0])
cylinder (h=7,r=11);
translate ([-13,-40,35])
rotate(90, [0, 1, 0])
cylinder (h=20,r=9.5);

//hueco pa caja de bolas DERECHA;
translate ([-13,40,35])
rotate(90, [0, 1, 0])
cylinder (h=7,r=11);
translate ([-13,40,35])
rotate(90, [0, 1, 0])
cylinder (h=20,r=9.5);

//lineal rollers 80mm center to center;
translate ([0,40,0])
cylinder(h = 24, r= 7.5);
translate ([0,-40,0])
cylinder(h = 24, r= 7.5);

//passthrough roller holes;
translate ([0,40,-2])
cylinder(h = 60, r= 5);
translate ([0,-40,-2])
cylinder(h = 60, r= 5);

//ziptie holes left;
translate ([-12.5,-52,3])
cube ([12.5,2,5]);
translate ([-12.5,-52,16])
cube ([12.5,2,5]);

translate ([-12.5,-30,3])
cube ([12.5,2,5]);