I get the fact that rotating the cylinder is just as effective as rotating the spiral screw, but I don't understand why rotating the cylinder is better? Why would the original idea of rotating the screw not be "a constant flow"? Why would it produce more dust than rotating the cylinder? I'm really confused as to why this invention is even necessary?,(reply>), @Neko Alosama I guess that makes sense, and I suppose the rounded scoops would be gentler, but I still don't get why moving the walls instead of the screw reduces the cutting/grinding risk. Either way, you've got a seed or something stuck between the wall and the semi-"sharp" screw. To use an analogy, whether you move the knife or move the object over a stationary knife, it will still cut. Is it just that there's less probability of getting stuck in that position? but even then, I don't get why that would be. Maybe I'm just stupid. :-),(reply>), The material being transported can be damaged when moving through a rotating screw. The screw coils can either cut into the material (if they're thin) or grind them against the walls. This is why some grinders are just large rotating screws.<br><br>As you can see in the video, the cylinder uses rounded scoops to pick up the material, so the material can't be cut. The material is also moved up the screw by moving with the rotating walls, so the material wouldn't grind as it goes up the elevator.,(reply>), My question exactly