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A Detailed Tutorial on PAM Cannon Pin Modification

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An awesome tutorial from Francisco


The maker Panerai, as many manufacturers, buys movements from ETA in order to modify them. The aim is to have movements with an exclusive looking. In the case of PAM movements that do no have chronometer function, the movement employed is the ETA 6497 (many times known as Unitas).


Panerai employs the tallest possible cannon pin, but, many times, the replicas uses a shorter one, and the difference is quite visible. However, as the gen uses an ETA movement, spares are available, and this flaw can be solved.


Firstly, let us show the difference. Next picture, no modded cannon pin:




Modded cannon pin:




There are three ways of making this mod, depending on the way the cannon pin is installed:


1.- Newbies method. The fastest and easiest. Very low skills needed. However, there is a chance of producing damage in some gears and in one jewel if you are not careful.

2.- Amateur method. More complex than the previous one. It requires some experience to place a spring bar in its place. Much better than the previous one, because it eliminates the risk of damaging the gears.

3.- Professional method. No risks…but a jewel press is needed.




I am employing here pictures from two cheap 111H and 112H rep watches. The first step is to buy the pieces needed for the mod. The references for cousins web store (www.cousinsuk.com) follow:


1.- Hour wheel, 2.15 height. Reference UT6497250H215.

2.- Cannon pin, 3.15 hight. Reference UT6497240H315.



Next task is to remove the movement from the case, for removing dial and hands. The first task is to unscrew the crown guard, in order to remove the stem.




Next is to unscrew the back.




In order to remove the stem, the screw shown in next picture has to be unscrewed a bit.




In order to remove the mechanism take out the screws shown in next picture.




Next picture shows the mechanism out the case. In addition, the picture shows a trick to protect the dial and hands from the hand remover, to avoid scratches. A small piece of plastic will do the job, hugging the hands. PAM black hands are very easy to scratch.




Next step is to free the dial. Just unscrew a little bit the screws shown on the picture.




After removing the dial, next picture shows a golden washer on the hour wheel. Just remove this washer.




And you will see this:




Next task is to remove the hour wheel, no effort is needed.




Now it is time to remove the cannon pin. It requires a lot of strength to remove and to install the cannon pin. You will hear a click when the cannon pin is installed correctly. To remove it, the hand remover is employed:




Next picture shows the removed cannon pin. The red arrows shows a jewel that was under the cannon pin. We shall talk about this jewel soon, because there is a potential risk of damaging this jewel.




Next pictures shows the differences between the parts we have bought and the parts from the replica. Comparison of cannon pins. New cannon pin on the left.




Comparison of hour wheels. The new on the left




We have just seen the common steps to the three methods. Now the three possible methods are explained separately.





This is the easiest way for making this mod. Directly now the new cannon pin is installed. Just put the new cannon pin in its place and press it down until a click is heard.

However, you should be very careful. Firstly, the teeth of the cannon pin (green arrow) must fit the teeth of the minute wheel (red arrow). If the teeth are not in the correct position, when the cannon pin is installed by pressing it, you can damage some teeth and this will affect to the correct running of the watch. Take into account that you place the teeth in the correct position but while pressing down the cannon pin can rotate a bit.


I have simulated this step many times and I never damaged the teeth. However, the risk is there, and many modders do not recommend this method. On the other hand, next method solves this problem, but it is really more complicated for newbies.




Once the teeth are aligned you can press down the cannon pin. The most convenient way is using the tweezers.




Put your finger on the tweezers and slowly increment step by step the strength on the tweezers… until you hear the click...then stop pushing.


It is very important that you do not apply any strength horizontally. Do not press horizontally. Otherwise, you can damage the jewel under the cannon pin. This is another possible risk. Jewels are very hard, but brittle. Last method solves this possible problem.


Now it is time to install again the hour wheel (the new part) and the washer. Next pictures shows the hour wheel installed, only the washer is not in its place.




Next step is to install dial and hands. However, the minute hand needs modification. Next picture shows the technical dimensions of the cannon pin.




As seen in the drawing, the available space for the minute hand is 0.45 mm. The tube of minute hand of the reps is normally larger, more than 0.45 mm.


Let us check the length of the tube of the minute hand of the rep. It measures 0.58mm.




Therefore, you have to file it. Next picture shows that we have placed the minute hand, protected with a paper, on a piece of wood, and fastened with tape. A fingernail file is employed to file…be careful... do it slowly and check each time the length…with the objective of 0.45mm.





Stop when it measure 0.45mm. In my case I obtained 0.44mm…that it is the same…of course.




Now the mod is finished, hands can be installed.












With this method we eliminate the risk of damaging the gears. However, it requires some skills to install a spring bar. This method consists of removing the minute wheel…so there is no risk for the teeth of this gear and the teeth of the cannon pin.


We assume that we have removed the cannon pin, as shown before. Next step is to remove the screw shown in next picture.




Then the part sown on next picture (setting lever jumper) can be removed.




Next picture shows what you will see when the setting lever jumper is removed. Pay attention to the spring bar shown by the red arrow.




Probably this spring has jumped…if not… it will jump when you install the cannon pin. Some people recommend using Rodico for fastening this spring. No way, it will jump when you remove the piece of Rodico… It always jump! Therefore, we remove the spring just to control it.


It is very important to have a magnet bar (for fastening knifes or similar) when you dissemble a movement. If a part jumps…you can find it easily. NEVER BEGIN TO DISASSEMBLE A MOVEMENT WITHOUT A MAGNET BAR.



Next picture shows the movement after removing the spring bar.




Now it is time of removing the minute wheel and installing the cannon pin. No problems for the teeth. However, be careful of not damaging the jewel.


Next picture shows the cannon pin installed, before installing the minute wheel.




Now the minute wheel is installed and the spring bar is placed on its place. It is not easy to install the spring bar. I give you a way to do it that works well for me. Do not panic, first time you will not do it… but after a couple of trials you will find it easy.


Next picture shows how a wood bar is fastening the part where one of the arms of the spring bar will be pushing on. This part is pressed down, to avoid jumping when the spring bar begins to push it. Then, use your tweezers to fasten the arm of the spring bar and put it in its original place.




This is the result:




Now it is time for assembling the setting lever and screwing it, as seen in next picture. However, a final step must be done.




Red arrow of previous picture shows the problem. We have to fit the end of the setting lever with a pin of another part. This pin is now under the setting lever end. It is not visible in this picture.


Just move a bit the end of the setting lever, and this is the final result you must achieve:






Previous method eliminates the risk of damaging the gears. However, there is a small probability of damaging the jewel under the cannon pin. With care no damage will be produced…. but… there is a better way to do it.

The professional method employs a jewel press. A jewel press permits to fix the maximum distance you can press down and pushes only vertically. Follows some pictures of the second hand jewel press I bought on Ebay. Pay attention to the regulator…this fixes the maximum distance…










Some modders file the cannon pin. I find this task superfluous because it is hard to see the final effect. However, you can do it with no risks and it is not difficult. As seen in next picture, normally the cannon pin has a small tip.




However, Panerai watches have no this tip. Therefore, to eliminate this tip you must file 0.05mm. After filing you have to polish the top of the cannon pin, for example, using cape cod.


In my opinion, it is very hard to distinguish a filed cannon pin. Next picture shows two cannon pins. One has been filed. Which one?




However, in some pictures taken with zoom it is possible to see the tip or the absence of tip in the cannon pin, as next picture shows (cannon pin filed).




If the cannon pin is filed, the tube of the minute hand must be filed to 0.4 mm, instead of 0.45mm.


Thanks for reading,



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Is it possible to fix this last pictures? I really like this tutorial! Thumbs up!

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Is it possible to fix this last pictures? I really like this tutorial! Thumbs up!



Done. :lol:

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Perfect! Thanks a lot!

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very nice :)

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I love this tutorials.. Im very far from trying this at home..

but is great to know how...


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Much easier way - any local lathe guy will make little pieces of stainless steel or any other metal, for $5 a dozen, so, just insert it, like on picture, that's it.



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Hi, for the recent Pam 3XX models that uses the 7750, is it true that you can't flatten the cannon pinion mod?

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A fantastic tutorial. I just ordered the pieces at cousins after having followed one of your other tutorials about superluming.

Thousand thanks for this great job.


:thumbsup: :thumbsup: :thumbsup: :thumbsup: :thumbsup:

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