Today when i started using my glowforge my cut was pretty far off where it should be. So, i used another piece of wood and positioned it where the edge did not matter. As you can see by the pic my print is now 3/4 of an inch off left and right, but pretty much on track top and bottom. Ever since I have had my GF the cut has been pretty much 1/8 of an inch off and i just use the ruler to position my material accordingly. This is right under the center camera, it gets worse further toward the edge.