Everyone has their own ideas as to how they want to set up their high-banker. The one most important question you want to ask yourself is: Am I going to classify materials before I put it into the hopper?
When I designed my first high-banker I didn't take into consideration the weight of stones shoveled into the hopper. With a 16: wide grizzly, the use of undersized rods was foolhearty as they quickly sucame to the weight of a full #2 shovel load, one after the other. So rods were replaced with a plasma cut 1/2" slot 1/4" thick plate to absorb the weight. This worked great for the weight, but allowed too many unwanted rocks/pebbles to work their way in and fill in the first foot of riffles. Enter stage 2: A piece if 1/4" punch plate angled directly under the grizzly, but above the hopper mat. The welded angle support allowed the oversized material to wash down the sluice body and be discarded.
My high-banker is 16" wide, and 102" long. It's in three sections and is fed by a 2" spray delivery system with 6 different classification style riffles, and 4 different styles of matting. It can also double as a 4" dredge/highbanker in shallow streams/rivers. Years of tinkering will only leave you with more questions: What do I do to improve on yields? You'll always be asking yourself what next. Ideas from others help only so much. You've got to go out and run your construction in the field to determine, What next?
I hope this helps. Saludos!
Sergeant Major Nichols (R)