During the examination it is our task to troubleshoot issues with the watch which have been introduced by the examiners. During dis-assembly you identify and fix the problems, then all that remains is to clean the watch and recase it with a high level of accuracy and cleanliness as both will be factors in the grading.
Besides the overhaul there is a written portion of the exam and a polishing exercise, both of which are proceeding nicely for.
I have taken some pictures of a practice overhaul and will offer a brief explanation of some of the steps below.
|The caseback has been removed|
|The rotor and stem have been removed, the movement can now come out of the case|
|Removing the hands while protecting the dial and hands with some plastic|
|The dial-side with the dial and date ring removed, nothing to repair on this side!|
|The hairspring is not centered, the coil spacing near 11oclock are wide and near 5 they are narrow, which will need to be corrected by bending the spring|
|Another shot, the dogleg in the spring near 12 o clock seems is where we will perform the correction|
|The entry pallet stone is not level in the fork, it has dipped out of its holder and needs to be reset so it can engage the escape wheel|
|The tilted stone|
|Using an electric heater and this expensive gauge it is easy to move the stones in or out of the pallet fork micro-metric amounts for precise depthing correction which is essential for a well-running watch|
|The endshake (up and down movement) of my pallet fork was too small, so here I am pressing the jewel back into its bridge. Once the jewel was flush with the bridge the endshake was back within tolerance|
|Here I am adjusting the barrel endshake, which was also much too small. Too little endshake reduces freedom of the wheels and introduces extra friction into the mechanism.|