I've found Jendritzki's books, particularly "Watch Adjustment", indispensable if you decide you want to learn more.
I've gotten to where I personally regulate every one of my pieces, even when they're freshly back from my very, very competent watchmaker. No one has more to gain than the owner of the piece, so I'm likely willing to spend far more time in regulating my pieces than would be practical or economically viable for most watchmakers.
You've only just scratched the surface. There's issues of temperature, position, and isochronism to consider. And with vintage pieces, add in the challenge of movement parts with varying degrees of wear.
It's really satisfying if you're the nit picky type with your watches.
Just to introduce some consistent language to the discussion, "regulating" is the simple and typically very quick act of moving the average rate of the watch. If it takes you a lot of time to do this as a professional watchmaker (referring to your comment about the time needed) then you should look for a different profession.
😉
"Adjusting" on the other hand is a whole different thing, and this is what takes the time. This is a portion of a post I made on another forum a while back, and it explains the difference between adjusting and regulating, and how some very basic adjustments are done.
Adjustment is more involved than regulation, and often people use the terms to mean the same thing. These are two different things, and one must be done before the other, so I'll try to show some basics here that will hopefully explain the difference between adjusting and regulating.
Movements are checked in several positions, and some positions will run faster or slower than others. The difference between the fastest and slowest position is called the Delta, and getting that number to be as small as possible is what adjusting is mostly about.
So to explain graphically what I mean between adjusting and regulating, I have made this little chart that shows three different conditions for the rates of a watch:
So the X axis is seconds per day that the watch runs fast or slow, with the black vertical tick being "zero" so no gain or loss. The red ticks on each line represent the rate the watch runs in the fastest and slowest positions, so the spread of the Delta figure.
So the top example is pretty good, with the spread being small, and more or less centered on the zero point. The next one is still quite good, with the spread being quite small, but the regulation is off, so the spread is shifted to the slow side. The last one is the worst case I show, where the spread is centered, but quite large. Of course the spread can be large, and not centered as well.
So in this scenario, the centering of the spread is regulation, and the width of the spread is adjustment. For now I am going to confine this discussion to a watch equipped with a flat balance spring and a regulator. Introducing an overcoil complicates the scenario, as does a free sprung balance, so for now we'll keep it simple.
Regulation typically consists of turning a screw, or moving a lever to adjust the centering of the spread on my charts above. It is a very simple thing to do, and anyone with a small bit of dexterity can be taught this pretty quickly.
Adjusting is another matter, and it involves some things that every watchmaker should be able to do, but hobbyists may find a bit daunting. I am going to use an example that is super easy to work on, an ETA 6497-2 from a Panerai 112 I serviced:
This example has a flat balance spring, regulating pins, and has the great system that ETA uses called ETACHRON, which quite frankly makes adjusting very easy for anyone with even basic formal training to accomplish. I have added two labels to the photo above, and the "A" is on the adjustable stud carrier, and the "B" is on the regulator. The stud carrier is where the outer end of the balance spring is anchored, and as the name suggests, it is adjustable radially, centered on the balance staff, to dial in the beat error. The regulator at B is also adjustable radially to adjust the average rate faster or slower. The regulator adjusts the effective length of the balance spring to make the oscillations faster or slower.
The other thing you might notice about these two points is that there are silver and brass (respectively) coloured parts that are shaped like a rounded rectangle. This is part of the ETACHRON system, and these make adjustments very easy compared to watches that are not equipped with this. So I do all my adjustments using a 10X loupe, and also with the two tools shown below:
On the left is a pair of #5 tweezers with fine tips, and on the right is the ETACHRON tool. Here is a close view of the tool:
As you can see this tool has a recess that fits over the rounded rectangles at the regulator and stud carrier. I can fit this over both the stud and the regulating pins, and use it to turn each of them. Turning the stud will change the centering of the balance spring, and turning the regulating pins will open or close the pins on the balance spring.
I do all my adjustments with the watch as seen above, so the movement has been cleaned, the balance jewels lubricated, and only the balance installed on the main plate. This allows easy access to see all around the balance wheel so I can get a very good look at the spring from all angles. The first step is to turn the regulating pins to their most open point, and in this case the balance spring is free from any interference from the regulating pins. I then look at the spring from the side to determine if the spring is level and flat:
So here I use my eye to check the spring and compare it to the balance wheel. The spring should be parallel to the balance wheel - it's more difficult to see in a photo than it is in real life. If the spring is parallel to the wheel, that's good, but sometimes you will find that the spring is a straight line but angles up or down from the wheel, and you use your tweezers to push up or down on the spring where it meets the stud to correct this.
I also check to make sure it's flat. You will often see that the spring is a half dish shape, where say on the left it's flat, but on the right it's dished up from the middle of the spring out. This means a coil of the spring is twisted, so using the #5 tweezers I bend the coil to make the spring flat again. I used an Asian 6497 clone that I had in my junk drawer (replaced one with a Swiss movement for a client) to illustrate this. Here I have intentionally tweaked the balance spring to show the half dish:
So once the spring is flat and level, then I move on to centering. I need to make sure that the coils of the spring are concentric around the balance staff at the center of the balance wheel. I do this by looking from above, and comparing the spacing of the coils at 180 degrees from each other. In this example (back to the Panerai) the watch arrived to my shop with the spring not centered properly:
As you can see, the coils on the left side are quite a bit closer together than they are on the right side. I adjust this by using the ETACHRON tool and turning the stud - the adjustments needed are very small to move the centering a lot, so this requires a delicate touch to get it right. Once I have the coils concentric, I then look at how the outer coil is centered between the regulating pins. Note, the angles are difficult to get just right in photos, so again much easier to see correctly in person. Again here you see this one is not good, as the spring is nearly touching the left pin:
So I again use the ETACHRON tool to adjust the stud to make the coil centered between the two pins:
But when I do this, the concentricity of the spring goes out again, so I correct that by manipulating the outer coil of the balance spring with my #5 tweezers, either pushing or pulling on that coil to open or close the coils on one side. It can become a bit of a cat and mouse game, and you need to go back and forth between the looking at the coils from the top and looking at the coil in the regulating pins - when the coils are concentric and the coil is dead center between the two pins, that part is done.
The last step is closing the regulating pins back up with the ETACHRON tool. This was next to impossible to photograph, so I'll simply explain that as you rotate the regulating pins with the tool, the space on either side of the coil grows smaller and smaller. Again using a 10X loupe and now with the balance wheel oscillating (you can simply flick the movement holder and it starts to oscillate back and forth) you slowly close the pins until there is a very small gap on each side of the coil as it moves back and forth. A rule of thumb is that you want the total gap on both sides to equal about the thickness of the coil of the spring, so this is a small gap.
I then carry on with the service, and once the movement is running, I put it on the timing machine and check it in 6 positions. I then use the data I get from that test to decide if anything needs to be tweaked. The most common adjustment I make at this point is how tight those regulating pins are to the coil in the last step above. Certain patterns in the positional checks can indicate that the pins need to be closer together, or perhaps further apart to make the spread between the fastest and slowest position as small as possible.
So this is the very basics involved in adjusting a watch movement. The procedure above will influence the watch's performance in many ways, and hopefully is enough to dial in the Delta so that it's easy to regulate the watch to a stable rate over normal wearing conditions. I follow this procedure (or something similar depending on the design of the movement) on every movement I service.
In some other cases there are further adjustments that can be made through procedures like static and dynamic poising, but they are a bit difficult and lengthy to explain, so I'll leave it as this for now.
I hope this gives you some insight into what adjusting is all about, at least on a basic level.
Cheers, Al
