Thanks to everyone for their very helpful suggestions. The one I made was a combination of the plans from Glenn Bradley & Jim White. It's 2' x 4' with a pegboard top, 1/4 inch MDF bottom which I slanted from top to bottom, I used MDF for its smooth surface (I thought the resistance would be lower than plywood.) The sides were simply 2"x4"s rabbeted to accept the pegboard. I left the pegboard top loose so I can remove it to clean it out if necessary. Cost was less than $20 & it works pretty well
Thanks again
Dennis