I am trialling MEP 2010 for an upcoming project and was wondering if there is a way of adding 50mm of straight duct to rectangular elbows. I have created a custom elbow, however I would need to do this for each duct size. I have noticed that standard fittings with small, medium and large radius have the 50mm straight section, however the 1.5w,1w and 2w elbows do not. I am using 0.5w radius elbows.