This makes it extremely easy to adjust the chime and strike trains so they can start with adequate vigor and stop with all of their components coming to rest in the correct position. The procedures for maintaining spring driven movements are just a little bit different than those required for weight driven units. As the mainsprings exert a tremendous amount of force against the train wheels there is always the opportunity for a winding accident to occur. This cam is often referred to as the snail because of its shape. Check for wear or rough surfaces on the pin or hook if this is not the case. The industry standards provide a set of guidelines that are notoriously difficult to understand and challenging to implement. Many movements have bim-bam or double strike features that provide a delayed stroke on two gongs producing a different tone.
Drill a hole in the sheet metal that is just slightly larger than the empty weight holes that are to be filled in the rim of the balance. When the trial fitting has been accomplished successfully, drive or press the plug in place. The lower steps on the cam allow the rack to drop farther down, causing a need for more teeth to be dealt with before the striking train shuts itself off.
The wheel attached to the winding arbor has a total of seventeen teeth. The train should shut off with a sharp click. If the hook jumps or is kicked out of the way before it can lock, the relationship between the wheel that drives the fly, the locking disk or the control cam is not correct. Using this very basic description of how Hermie movements operate as a framework, the more technical aspects of timing each of these events to occur at the correct time can be addressed in greater detail. Therefore, it is best to leave the mainsprings until the end of the cleaning cycle.