I think I have seen three of these on the net, and a bunch of others that use the large steel wheel with an ax head welded on. Not enough safeties for my liking. If the baler has a proper shear pin on its flywheel it might be mechanically safe but it needs some sort of loading chute so the operator doesn't get close. This might be the one where the fellow dismantled it after jamming it and found that it had broken two teeth in the drive gears. It could be made safe but these ones are too slap dash.