Am a little confused and it’s probably very elementary but how do you know the differences between gears T1, T2 etc. Is there an obvious recognition pattern (size or position). It is not to me readily apparent when you remove them in your video as to how they are identified – you simply state that is what they are…
Yes you can usually identify the wheels (gears) by size, descending in diameter from the mainspring barrel down to the escape wheel. You can call them anything you wish actually. I use T1 etc. just to help identify them when teaching. A more common terminology used in clockmaking is Great wheel, Center wheel, etc. With watches…first wheel, second wheel, etc. When first starting out it’s often a good idea to take pictures of the disassemby process. Especially when working with more complicated striking and chiming movements.