I would like to clarify hand crank vertical stuffers called two speed stuffers They are not used to stuff at two different speeds, A stuffer that has two speeds are designed to stuff at a low speed setting only. A ratio is changed when the handle is moved from one spline shaft to another. When the ratio is changed, the torque on the gears are also changed which will place added stress on the gears at a higher ratio when applying pressure (pushing meat through the stuffer) to the gears and shaft. This is where an equipment failure may occur when the higher speed is selected for stuffing.
Two speed stuffers only come in larger taller stuffers thus the need of two speeds. The higher speed option is there only to raise the pusher up and out of the stuffer for faster accessibility in removing the stuffer for repacking and also for returning the pusher to the bottom before storing. The lower speed is recommended for the stuffing process only
I hope this clarifies 2 speed stuffers. If anyone has anything to add, Feel free.