Aaltoblock

// AaltoBlock.scad - Basic usage of text() and linear_extrude()
// size of the letters
s=25;
// letters you want to type in a block go in ()
LetterBlock("A!");
// Module definition.
// size=30 defines an optional parameter with a default value.
module LetterBlock(letter, size=s) {
   difference() {
       translate([0,0,size/8]) cube([size,size,size/4], center=true);
       translate([0,0,size/8]) {
           // convexity or preview to deal with concave letters
           linear_extrude(height=size, convexity=4)
               text(letter, 
                    size=size*22/30,
                    font="Bitstream Vera Sans",
                    halign="center",
                    valign="center");
                               }
               }
}