Update: Hairspring Vibrated! Also, where I’ve been…

As the title of this post states, I successfully vibrated my hairspring! I actually did it about a week or two ago. I wanted to wait until I had finished the project and had some time to think about before I wrote about it. I also didn’t want to do a bunch of small updates that would have amounted to “Well, I’m not done yet…” “Well, I’m not done yet…” “Well, I’m not done yet…”-that would have been depressing to write and boring to read.

If you read my last post, you know that I had messed up the process by trimming too much off of the end of the hairspring which meant that I wasn’t able to make corrections to where the stud needed to be (which also meant that I wasn’t able to make adjustments to the position of the hairspring at the collet).

I’m going to quickly go through the process while also adding some details that I left out of my last post.

When I got back to school, I got a brand new hairspring and started the process all over again.

WP_20150120_09_06_22_ProI was able to re-use the stud and collet from the first go around as well as salvage the pins that I had made for each.

hairpsring intial formThe first step was removing just enough of the inner coils to allow the collet to get situated on the newly formed tongue.

WP_20150120_09_25_22_ProHaving a collet tool makes putting the collet on the hairspring (as well as putting on the stud) a much easier operation. Having the hairspring stay relatively level (more on that later) when securing it with the pin was a blessing. The other way to do this is to put the collet on a broach, then slide the hairspring onto the collet, and then try to pin it… No thanks.

After pinning the collet, you now need to make some general corrections to the hairspring to get it roughly centered (more on that later) around the collet. Once the rough corrections have been made, the hairspring goes on the balance wheel and then on to the vibrating/luthy tool.

WP_20141203_10_36_02_ProIn my last post, I had a couple videos showing the beginning and end results of using the vibrating tool. This time, I have a video that shows what it looks like starting at the very beginning of the process to the end. The videos have been slowed down, so the video is about 5 minutes long, but it gives you a good idea of what I was looking at, and for during this part of the process.

Once you have the initial vibrating point found, you need to fully make sure that the hairspring is completely flat and centered at the collet.

WP_20150121_10_09_02_ProTo do that, you use a pair of true calipers and give the balance wheel a spin. Watching the hairspring from the side and the top will let you see if the hairspring is kicked at an angle or wobbly at the collet. Take a look at the video below. The second part of the video was slowed down so you can really get a good idea of the kind of movement the hairspring will have when it isn’t centered in the round.

The best way to go about fixing the out of flat is putting the balance on a broach and, well, fixing it. If it is kicked upward, you need to grab the hairspring where it is exiting the collet and bend it down, and vice versa if it is kicked down.

WP_20150121_10_12_04_ProTo fix the out of round, you need to treat it like you would a typical out of round issue-but this time you need to visualize how you are going to shift the hairspring (if it is expanding out to the right, you will need to address the hairspring at the collet by bending it to the left to give it an even expansion and contraction).

This is the next difficult part. When you are are addressing the out of round, it is easy to kick it out of flat and vice versa. The space that you are dealing with is very small,

Hairspring 2

While it is kind of washed out, if you click on the picture, you can see the space you are working with for centering in the round and getting it flat

and even using a pair of #5’s, it’s very easy to make an accidental change to what you just fixed-so you are chasing one issue with another.

After you get the hairspring centered and flat, you need to place the stud on the spring and have it 90° away (towards the end) from the vibrating point. A quick eyeballing is all it takes initially to get the stud on the hairspring. Leave as much excess hairspring as you can (at least a half turn of a coil after it exits the stud) at this point. This is where I tripped myself up last time.

WP_20150127_14_13_24_ProClick on the above picture. You can see that I left about 1.25 turns of the excess spring for the next phase of this process. To ensure that it wasn’t going to interfere with the movement of the balance, I brought it up and over the top of the bridge-since the spring that is on top of the bridge is coming from the stud, it won’t impact the expansion or contraction of the active length of the spring.

Once you have the balance assembled, re-install it on the watch and it is time to start the next part. You need to put the watch in static beat, then move the regulator arm so it is in line with the cap jewel, pallet and escape arbors. Once you do that, double check that the beat regulator arm is 90° away from the regulator and wind the watch and time it out. What you are looking for at this point is the Beats per Hour. It must be at 18,000. If it isn’t, you haven’t put the stud on in the right place. To correct that, you move the regulator arm until the BPH reads 18,000, and then move the stud the exact same amount of distance (hence why you do all the initial lining up of the regulator and beat regulator-it gives you good visual clues). If the watch is running fast, say 18,050 move the regulator closer to the stud (increasing the active length of the spring which means a longer time to expand and contract) to slow it down until it reads 18,000. If it is slow (say 17,050), move the regulator away from the stud (decreasing the active length which decreases the time of expansion and contraction) to speed it up.

You will probably need to do this a couple of times to get the stud in the proper position, but once you do, you are almost done. Before you clean, oil and time the watch (properly), you need to center the hairspring to the bridge and put in a corrective bend. I’m not going to lie-I was extremely nervous about putting in the corrective bend. The corrective bend is called a bunch of different things (corrective, dog-leg, zig-zag, etc), but I prefer to call it nerve-wracking. Well, from this vantage point of having done it, it isn’t too bad, but I was terrified at the time. When you center a hairspring to the bridge, you take the hairspring off the balance and place it on the bottom of the balance bridge (like if it were in a watch). You screw the stud in place and you are checking to make sure that the collet is directly over the balance jewel (it won’t be).

WP_20150128_09_31_17_ProAt this point, you can start making small nudges and pulls at the hairspring near the stud to move it a bit, but the only real fix is going to be putting in the corrective bend. The shape of the corrective bend will force the hairspring over and up/down and get it the collet where you need it. After you form the corrective bend, then you can play with the hairspring at the stud or change the angles of the corrective bend to get it perfect. The corrective bend needs to be formed after the hairspring exits the regulator, but it can’t be too close to it.

Forming the corrective bend can be done two ways-on the balance wheel or off. There are pros and cons to each. Forming it off the balance wheel gives you the greatest amount of control so you don’t create an out-of-flat bend but that control sacrifices your visual landmarks of where it needs to be in relation to the regulator. Forming it while the balance is in the watch gives you the best visual markers, but it increases the chance of kicking the spring out-of-flat. I don’t have any pictures of the process, but I will say that I spent a day (seriously), going through random hairsprings from my first semester making tons of bends.

The easy way looks like this:

Dogleg 1

You have the hairspring off the balance and you pin with some #3 tweezers where you want the bend to start. Using a second pair of #3’s and “open” up the spring. Moving a bit away from the first bend, pin the hairspring again and “close” it. Finally, you will need to nudge the hairspring a bit so it doesn’t have such a sharp initial angle.

The hard way (the way I ended up doing it) involves leaving the hairspring on the balance and in the watch and only one set of tweezers. It looks like this:

dogleg 2.5


You pick your spot and angle the tips of your tweezers to do a pinch bend. Your hairspring is going to look crazy after that. Move further along, and do a second pinch bend which will cause the spring to correct the curve. Go back to where you did the initial bend and move it so the hairspring is creating a concentric curve.

I started and stopped this process so many times. I was nervous because if you remember, this was my third hairspring. My first one broke at the tongue when I was reforming it, the second one I cut too much off the end, and I’ll be damned if I was going to do this a fourth time because I screwed up the corrective bend. Once I got the bend done, I had to correct an out of flat that was in the central portion (the straight part) of the corrective bend. It wasn’t too bad, but I took my time so I would get it right and not screw anything else up.

WP_20150203_10_16_17_ProIf you click the picture, you can see my corrective bend that I put in place. I think part of my hangup with forming the corrective bend is you spend a good chunk of time trying to fix bends in hairsprings that are messing with the function of the watch. To purposefully put in a bend to make the watch run better is a paradigm shift that takes a moment to accept.

I cleaned the watch, oiled it, timed it and it looked good. Except for the pallet fork. It gave me some trouble. I had to run it through the ultrasonic a couple times, went through some pegwood sticks, some watch paper and changed out my OneDip solution a few times before those jewels were sparkling clean.

I don’t think I was any prouder of myself once I turned in the watch-clean and running. It was definitely the hardest thing I’ve done and now that I’m past it, I can breathe a sigh of relief.

Some of my classmates and some watchmakers I have talked to have asked me if it was frustrating doing something that I probably would never do in my professional career. Having thought about it for a bit, I can say that I think the purpose of the exercise wasn’t necessarily to learn how to vibrate a hairspring, but it was learning the individual steps that made up the process and how to apply those in the real world that was the lesson.

For example:

  • learning how to center a hairspring in the round and ensure that it is flat at the collet will help me potentially avoid having to replace a hairspring if I notice it is sloppy when running.
  • Going more in-depth into static-beat will help me when I am getting ready to time a watch so I don’t rely just on the beat regulator to do things for me will make my work even better
  • Spending a few weeks working with a hairspring, forming the tongue for the collet and more importantly successfully creating the corrective bend has mitigated a lot of my apprehension to working with hairsprings
  • I am very comfortable working with collets and studs which will help me if I do need to replace a hairspring. Being able to use the original collet and stud that was matched with the balance is always a good thing.
  • If I am in a situation where I need to vibrate a hairspring, I know how to do it.


Now that I have this post out of the way, I am going to get back to a more regular posting schedule. I have started working with the lathe, so I will be updating my blog as I go through that process. I am looking forward to learning how to machine small parts, so this next section is going to be a lot of fun. It will be challenging, but it will be fun.


2 responses to “Update: Hairspring Vibrated! Also, where I’ve been…

    • Thank you! I am working on a whole slew of posts that should go up over the next two weeks that will get caught up on where I’ve been and what I’ve been doing (working on the lathe-and now getting back into watches).

      Sorry for the huge gap since I’ve posted anything!

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