Another observation.....probably relevant to all grinders and not just hand cranks......
Yesterday I did 15 pounds of butts into breakfast sausage and brats. Ground all of the cubed meat through a 1/2" plate, then divided into portions, mixed in the spices for each, and ground again through the 3/16" plate. This was using the #22 grinder. Actually took far longer to measure and mix the spices than to grind twice.........but I digress.
When cubing meat for a grind, I try to retain globs of fat, but get rid of blood clots, sinew, bone scraps, etc. Somehow I managed to miss some serious connective tissue. Souped up gristle....or ligaments. Grinders work by taking meat into the screws slots, which progress from wide open (coarse) to narrow (fine threads.....a type of gearing) and when meat hits the end of the screw, is pressed hard against the plates. The meat product bulges into the plate hole, and is lopped off each time the blade passes by. With four blades turning, that's pretty often. Interesting that the gristle would pass into the 1/2" hole and be cut off, but 1/2" sized pellets of gristle would not pass into the 3/16" holes. So what they did was accumulate in front of the blades. Floating barriers. It was still grinding, but was turning harder and was running slower. Meat was getting emulsified vs. ground. When I pulled the plate at the end of the grind, I found upwards of 10 to 15 of those gristle pellets had accumulated and were blocking the flow. The other thing that accumulates is sinew in the form of long strands of connective tissue which wraps around the hub of the blade....eventually blocking the blades from cutting. On the latter, the tighter the ring is, the less likely this is to happen.
For an electric grinder, it would mean the motor is having to work harder than it should. For a hand grinder, you are too. Point being to keep an eye on things. When it slows down and starts turning harder (you will notice by your own effort or the "hum" of the grinder motor), best to stop, clean out and start again if you are doing any type of quantity. Not only will it be faster and easier, but you get a better quality product.