Holy smokes its been a while...
Life had really taken over. As of late, I’ve been working on the Watchmaking Course and it’s really taken a great deal of my time. Not an excuse but hey. Just wanted to keep you informed is all.
One of the glaring concepts in watchmaking that’s often not spoken about in watchmaking is Endshakes (if you don’t know what endshakes are, bare with me for a little bit). Actually, there are a lot of things that are not spoken about in watchmaking but hey. Endshakes are one of them. Nevertheless, while creating the ETA 2892 Course, I searched endless amounts of text online for Endshake adjustments to no avail.
The little information that I did find on it was elementary at best. It was overtly complicated with little to no substance. From someone who actually understands Endshakes and adjusts them for a living (I guess I can say that?) I had no idea what the hell Endshake even meant from the way it’s portrayed online. I know for a fact that if I didn’t understand it, many others didn’t.
So without further ado, we’re going to be tackling the topic of Endshakes. Before you finally go, “Whoa, what the **** Anthony. What the hell is Endshake?” Let me answer that here and now.
The Art of Checking Endshakes.
WHAT IS ENDSHAKE?
When you’re becoming a watchmaker, you’ll realize that there are so many subsets of systems you’ll need to learn. Watchmaking is not just a matter of disassembling and reassembling a movement. There are many different facets combined under the umbrella of “watchmaking.” Endshakes are one of them.
Endshake is the amount of play a part (train wheel, pallet fork, etc.) has between the upper and lower jewels (or bushings) that hold it. Endshake is determined by the play of the top and bottom jewel that holds the part in. Every single watch needs a proper amount of endshake tolerances in order for the watch to run optimally.
ALRIGHT, CAN YOU TELL ME THAT IN PLAIN ENGLISH?
Think of Endshake as the amount of tolerance a part has. The industry term is called Endshake but switching it up and calling it tolerance works extremely well.
Let’s talk about shoes. It probably makes sense to buy a pair of shoes a little bit bigger than to buy a pair that is too snug. Why? So that you can have some flexibility and wiggle room when you’re walking or running. What happens when the shoe fits just right? It’s a perfect fit. Not too big and not too small. The shoes are optimal for you to walk and run in without having to hinder any performance.
Or even better, let’s talk about pants. We’ve all bought pants that were too big on us. You know, the ones that are too baggy in one part and not the other. I don’t know about you but I’ve also bought pants that were too tight on me (whether I gained weight or the pants shrunk, I can’t divulge.) Pants that are too big on you will just keep falling down. Pants that are too tight on you will squeeze the life out of ya. We can agree that whether it’s loose or tight, pants that are not the proper fit will hinder your performance. It’s not the optimal fit. Which begs the question, what is the optimal fit?
Optimal fitting pants are the ones that fit just right. It’s not too loose and not too tight. It’s loose enough for you to move around without feeling restricted. It’s tight enough that it’s not falling down or swallowing you whole. It’s the perfect size for you to move around and feel good.
SO WHAT DOES THAT HAVE TO DO WITH WATCHES?
Well here’s the thing. We know that watches have a shit ton of rubies, jewels, wheels, parts, etc. They all have to fit somewhere. Whether we are holding down wheels by the pivots with jewels or housing arbors within barrels, we know that in theory, everything has an optimal fit.
WHY DO I NEED TO KNOW ABOUT ENDSHAKE?
If all of these moving parts do not have an optimal fit, the watch will not run. Plain and simple. The proper endshake and tolerance of these moving parts are vital in ensuring that the watch runs smooth and for the longest amount of time possible.
HOW DO ENDSHAKES GET MALADJUSTED?
Endshake adjustments outside of watchmaker interventions are generally caused by impact damages and daily activities. There are many other causes but from an aftersales service perspective, these are the two main culprits.
If impact damage is strong enough to damage wheels, dials, hands, and pivots, it’s strong enough to shift jewels.
TAKE A LOOK AT THE GEAR TRAIN ASSEMBLY
For the sake of keeping it simple and concise, I’ll about discussing Endshakes within the confines of jewels holding down the pivots of wheels. This image right below is an image of the gear train assembly. We can see that the wheels are being held down by jewels at the top. There are also jewels at the bottom from the mainplate. The pivots of the wheels fit right inside the jewels. The jewels are designed to house and hold down the wheels while introducing as little friction as possible. Keep this in mind.
TAKE A LOOK AT THE LATERAL VIEW OF A WHEEL IN THE GEAR TRAIN
This is a lateral view of a gear train inside a gear train bridge. The jewels are denoted by the red parts at the top and bottom of the image. You can see that the pivots are inside the top and bottom jewels. If you take a look at the image above, you can see what this image is trying to convey. It’s the side view of a gear train inside of a gear train assembly.
LOOK AT WHERE THE ARROW IS POINTING IN THE IMAGE ABOVE
See that space between the shoulder of the pivot and the top jewel? That is Endshake. That is the tolerance that this specific wheel has. This wheel has the tolerance to move up and down at this point due to that space at the top of the shoulder.
HERE’S ACTUAL IMAGES DEPICTING THE ENDSHAKE OF AN ESCAPE WHEEL
Let me explain. On the left hand side you’ll see an image of the escape wheel sitting perfectly still without any intervention. Notice the red line that I drew at the bottom. This is the resting position of the escape wheel. We said that endshake is the tolerance a part has between the jewels that hold it right?
Take a look at the image on the right. You’ll see that I’m gripping the escape wheel with my tweezers. I’m actually lifting it up to see the amount of space and tolerance that the escape wheel has in between the jewels. You’ll notice now that there are 2 lines that I drew now. The bottom line in the 2nd image is the original line that I drew on the left. The bottom line depicts the escape wheel’s original resting position. The top line is how far the shoulder has been lifted now. Notice how high it’s actually going up. The pivot is almost out of the jewel itself. This is in essence what endshake is. The amount of play that a part has in between the jewels (or bushing) that hold it.
WHY DO WE NEED TO WORRY ABOUT ENDSHAKE?
Everything inside of a watch has an acceptable amount of tolerance and play. Endshakes can impact everything from the amplitude of a watch to the depthing of a wheel. If at any point, these tolerances are not within range, the watch will eventually stop running. Crazy huh?
WHAT HAPPENS IF WE HAVE TOO MUCH ENDSHAKE ON A PART?
You run the risk of a part disengaging if it has too much endshake. Too much endshake means it has too much tolerance. If it has too much tolerance, it’s going to be loose. Too loose means that it’s not optimal. If the endshake is too great, a watch will eventually stop altogether when the part disengages. Notice that I said when and not if.
Too much endshake also causes parts to behave erratically. For example, if a reverser wheel on an automatic system has too much endshake, it can cause the wheel to slightly tilt. Why would it slightly tilt? Great question. If the endshake is too high, we know that one (or both) of the jewels have been pushed away from the pivots. Let’s digress and talk about this in a slightly more detailed manner. If the jewels have been pushed away from the pivots, we know that the pivots are not as deep into the jewel as it should be. If the pivots are not as deep into the jewel as it should be, the wheel runs the risk of falling out. If the endshake is too high, we know that the pivots will eventually (not a matter of if but when) slip out or break off due to less surface area within the jewel, or damage other parts due to improper depthing. Got it? Good. Let’s move on.
Back to the example of the reverser. If the endshake is too high, the pivots of the reversers will either break off or slip out. Both of which will cause the reverser to slightly tilt. A slight tilt will wreck havoc and kill the service cycle of a watch. The slight tilt will cause the wheel to mesh into other parts or come into contact with bridges/plates that will ultimately grind down the wheel. As we all know at this point, the grinding down of anything isn’t good at all.
Think of it like wearing clothes. If your pants are loose/big, the chances of your pants falling off greatly go up. It’s too baggy. It might get snagged on things that you normally wouldn’t get snagged on if your pants were the proper fit. Most importantly, loose/big clothes will impede your performance. You wouldn’t want to wear an outfit that’s too big for you if you need to compete.
The last thing you would want is to have spent months preparing for a competition, only to lose because you tripped over your pants. It’s akin to watchmaking in the sense that you wouldn’t want to spend hours (even days) performing a complete service only for the watch to come back because a wheel in the gear train disengaged itself from too much endshake.
WHAT HAPPENS IF WE HAVE TOO LITTLE ENDSHAKE?
You run the risk of causing unncessary friction if there is too little endshake. Watch parts are supposed to have freedom within the confines of the movement. It can’t have too much freedom, and at the same time, it can’t have too little freedom. If there is not a sufficient amount of endshake, it can cause the part to rub against a nearby part thereby creating additional unnecessary friction and sheering.
The time keeping ability of a watch can be grossly affected by too little/much endshake as well. The additional friction from too little endshake will have a chain reaction all the way to the balance wheel.
Imagine if I told you to run a marathon with shoes that are clearly too small for you. Will that affect your performance in any way? I would venture to say that no matter how well you think you would perform, you could perform better if your shoes were the right size.
WHAT HAPPENS IF WE HAVE NO ENDSHAKE?
It’s very seldom but it does happen. If a part has no endshake, it has such a great deal of force to overcome in order for it to move at all. The part is essentially being squeezed from the top and bottom jewel. If a mainspring barrel or any part on the gear train has no endshake at all, the whole watch itself will eventually stop working. It’s similar to driving your car with the emergency brake on.
LET ME MAKE THIS CRYSTAL CLEAR
Imagine (if you will) that I drop you into an empty room with 4 walls. Now, I’m going to play God for a brief moment. Picture 2 of the walls starting to close in on you. Kind of like Indiana Jones style. The walls are now getting closer and closer to the point where the walls are now pinching you tight. You’re not dead yet but the walls are squeezing you to the point where you can’t move anymore. This is exactly what happens if a watch has no endshake. It’s being squeezed to the point where it can’t move anymore..
ENDSHAKES CAN BE CHECKED ON THE VERTICAL AND HORIZONTAL AXIS
Endshake is generally referred to in the vertical axis. The horizontal is what we refer to as sideshake. It’s something to pay attention to in the future but currently is not something I feel you need to worry about. Of course, I’ve heard differing opinions on what sideshake and endshakes are but to keep it as simple as I possibly can. Let’s stick with the endshake for the vertical axis and sideshake for the horizontal axis.
HOW TO ADJUST ENDSHAKES
This is a loaded question. It’s hard to show you without physically being there to walk you through the process step by step. However, the very least I can do is explain it to you as best as I can.
To increase endshake, you need to adjust the jewel further away from the part in question.
To decrease endshake, adjust the jewel closer towards the part in question
THE EASIEST WAY TO REMEMBER THIS
The easiest way you can remember it is that if you are increasing endshake, you need to adjust it away. If you are decreasing endshake, you need to adjust it closer. That’s probably the simplest way of remembering endshake adjustments.
VERY IMPORTANT INFORMATION REGARDING BALANCE AND ESCAPE WHEEL JEWELS
We’re talking about adjusting jewels for endshakes so it’s only right to talk about the balance wheel in-setting jewels. The jewels for the balance wheel are not there for you to adjust up and down for the endshake. Jewel caps do not serve to reduce endshakes. They are there as shock absorbers. Whatever you do, DO NOT ADJUST THE JEWELS to fix endshake on the balance wheel. There is no official endshake adjustment for the balance wheel. If you have a balance wheel that has the incorrect amount of endshake, someone was bending the balance wheel plate itself. Fixing that is entire article in and of itself. Just remember that you do not adjust in-setting jewels for endshakes.
Now I know I mentioned escape wheels jewels as well. This is not the case for every single movement. Most escape wheel jewels are regular jewels. You’ll find regular jewels for escape wheels in ETA movements. However, there are companies like Rolex, Patek, JLC, etc. that use in-setting cap jewels for their escape wheels. I’m talking about escape wheel jewels that look like this:
“WELL ALL OF THIS ENDSHAKE TALK IS GREAT, WHAT DO I NEED TO ADJUST ENDSHAKES? “
Great question. You will need a Horia tool with a set of pumps and anvils. It looks something like this:
These are the stumps for the top and bottom holes of the Horia tool. We commonly refer to them as punches/pumps and anvils/stumps. The more diverse your punch and anvil set is, the more watches you can tinker with for the most part. You can aim for a select few and get away with it if those are the only types of movements you’re working on but generally you’d want a complete set if you’re going to be serious about this.
A 15 set pump and anvil should do the job. It offers enough selections and varieties for you to cover a large majority of movements you might come across.
HOW TO USE THE HORIA TOOL
The Horia tool is such a versatile tool. We can use it for many things. One of the biggest uses of the Horia tool however is the use of adjusting endshakes. We can use the Horia tool to push the jewels closer or further away to adjust endshakes by selecting the right anvil for the bottom and the right pusher for the top. Take a look at the image below.
The pusher fits at the top section of the Horia tool and the anvil fits at the bottom. The size of the anvil and pusher will depend on what size jewel you’re going to be adjusting.
WHEN ADJUSTING ENDSHAKE, HOW DO I SELECT THE PUNCH?
Make sure the punch/pump (the top hole of a Hora tool) you select covers about 85% of the jewel in question.
WHEN ADJUSTING ENDSHAKE, HOW DO I SELECT AN ANVIL?
As a general rule of thumb, your bottom anvil should be one size bigger than your punch/pump. So if you’re choosing a size 60 punch, make sure you choose a size 70 anvil.
WHY DOES THE ANVIL HAVE TO BE ONE SIZE BIGGER THAN THE PUNCH?
Choosing a bigger anvil is crucial. Think of it as a fail safe. Just in case you push the jewel too much, a bigger anvil would allow the jewel to fall out perfectly fine without harm. If by accident the jewel gets pushed pass the bridge/plate, a bigger anvil would allow the jewel to come out.
If the anvil is smaller or the same size as the jewel, the jewel will crack if pushed pass the bridge/plate. The jewel has nowhere to go if the user accidentally pushes the jewel passed the limits of the bridge/plate. With the pressure from the punch coming down on the jewel and the pressure of the anvil from the bottom (being the wrong size), the jewel will crack and chip.
If the anvil is bigger than the jewel, the jewel will fall right out with no damage.
WHEN IT COMES TO THE HORIA TOOL, THERE’S A SECRET
Here’s a little secret about the Horia tool that not many people know about. Not even some watchmakers. Yes, you read that right.
ANSWER THIS QUESTION FIRST
Let me give you a hypothetical example. If a part has an endshake of 0.08MM and you need to adjust it so that it is within tolerance (industry standard is usually around 0.02MM to 0.06MM give or take), you will need to push the jewel down. Now, let’s say I want you to get the endshake down to 0.04MM. How many MM (hundredths of a millimeter) do I need to push the jewel down from 0.08MM to 0.04MM?
You might think that you’ll need to push the jewel down 0.04MM (0.08MM - 0.04MM = 0.04MM) to achieve an endshake of 0.04MM.
When it comes to the Horia tool, you’ll need to add 0.01MM to the correction. So if I need to achieve a 0.04MM endshake from my current 0.08MM endshake, I will need to actually push the jewel down 0.05MM to achieve a true endshake of 0.04MM.
WHY DO I NEED TO ADD 0.01MM TO MY CORRECTION?
This is because the Horia tool itself has an error in it. Within the gears of the Horia tool, there’s a certain amount of slack. The slack actually adds up to 0.01MM in cumulative error. So if you use the Horia tool and move a jewel down 0.02MM, you actually moved it 0.01MM because of the 0.01MM in slack the tool has. If you need to make a 0.04MM correction, you actually need to move the Horia tool 0.05MM. If you need to make a 0.06MM correction, you need to move the Horia tool 0.07MM. So on and so forth. Whatever the correction may be, add 0.01MM to the correction.
CHECKING AND ADJUSTING ENDSHAKE IS AN ART IN AND OF ITSELF
After you check and adjust endshake for a while (several years minimally), you’ll find that checking and adjusting endshake is an art in and of itself. Seriously. I’m not blowing smoke or trying to make this sound more complicated than it is.
I know many watchmakers who can grip a part (wheel, mainspring barrel, barrel arbor, etc.) and within a fraction of a section tell me what the endshake value is. You’ll know by heart what 0.0 and 0.06MM endshake feels like. You’ll even know what the difference between 0.03MM and 0.04MM feels like. It’s hard in the beginning (like everything else in life) but once you put in the work, I can guarantee you that you’ll immediately reap the rewards. You will never look at tolerances in your day-to-day activities the same again.
DID YOU LIKE THE WAY I EXPLAINED ENDSHAKES? YOU’LL LOVE THE ETA 2892 WATCHMAKING COURSE
I go over in video step-by-step how to do a complete service on the ETA 2892. The course is jam packed with PDFs, Instructionals, Reference Sheets, High Quality Disassemblies, Premium Podcasts, Microscope Precision Assemblies, and much more.