I am using a pivoting model of a turret (TF2) in a low budget film it is sitting on some cardboard which is being used as a barricade. The script calls for it turning but I can't see a way to do that easily because the only way I can think of is to use a ruler or stick to pivot the model. That is all good if I have to but the ruler would probably be seen in the shot. Any ideas on how to avoid this????