Ebay sends me notification for new listings of tobacco shredders. This one looks like a Tech type, but it's more of a chopper. I think this is a good design and with a few modifications could be a great design. I think the pivot point should be much closer to the blade. This would increase leverage and make cutting/chopping a lot easier. The throat wouldn't be as wide, but the wheel size could be increased to pick up some of the loss.
