yes you are right stvrob_63 i did have that problem at first. but trial and error is the key . i found out that if you have a scaling ruler like they have on the plans at flite test. there is no problem all you have to do is take a ruler and measure, and if you have at the starting the correct measure but then it gets shorter or longer. just twinst the projector to align and walla you are set. saves alot of time and paper.
currently i have an old movie projector and trying to take a picture of the plans with a phone and projected to the wall with the movie projector. what do u think?