Where did you find the model? The problem with this is that it has a set cut path which it steps down in Z to cut each face. It does the whole path, steps down and does it again. You cut a lot of air and each face took me 30-45 minutes.
If I could get a model I could program it to rough and finish and not cut air as much. I've not made any since the first. It was neat as heck but just took too long.