I am working on a catcher and am having problems getting the air to flow out with out the grass. Grass clogs the mesh every time I crank the throttle past half way. The mower is a 36" exmark metro hp. I do not have a blower on it but it seems pretty clear by the amount of old thatch and grass that its picking up with half throttle that I sould'nt need one. I am using a garbage can with a tapered lid that I have cut and replaced every place possible place with mesh, I am trying to use the garbage can so that I can use a trash bag and pull it out instead of other dumping methods. If anyone has seen how the grass is deflected in a trac vac or ultra vac please give me an idea of how it separates the two. If any one can give any other design ideas or help please do. I am wondering if I need to make a large free flow bin like an accelarater or fabric catcher, but then I would'nt be able to use trash bags to remove the leaves and grass. Thanks.