PAM "Fiddy" upgrade with a pocket watch movement., Details on installing a Hamilton 921 movement.

[onzenuub 307]

Originally posted by Ziggyzumba on RWG.cc. With his permission copied over here, just to build some watch threads.

 

I always like to challenge myself and learn new things. When it comes to watchmaking, I study and try and learn something new all the time.

 

I thought it would be an interesting project to re-engine my Fiddy with an old pocket watch movement.

 

The reasons I wanted to do this upgrade include:

 

1. Installing a higher grade 21 jewel adjusted to 5 position movement, not only for astetics, but for time keeping accuracy

2. See if I had the skills to modify the hour and cannon gears to accept my Fiddy hands

3. See if I could modify the case to accept a pocket watch movement

4. See if I could modify the stem to fit my Fiddy crown

 

So let me walk you down the path I took to get this modification accomplished. As with any modification, you have to follow a certain set of steps, but since we are dealing with a number of unknowns, you don't know if step A is going to work until you try it, and then you don't know if step B is going to work, and so on...any way along the road I could reach a road block and the whole project is dead in the water...

 

So knowing all of that, I start with what I think is the show stopper, modifying the existing hour and cannon pin to accept my Fiddy hands, without hands the watch isn't much good...

 

Modifying the ETA H3 Hour wheel and H3 Cannon pinion.

 

My plan is to remove the ETA hour wheel tube from an ETA hour wheel, and install this tube over the pocket watch hour wheel.

 

I chuck the wheel in the lathe and cut the tube off with a graver...

 

 

Close up of the ETA wheel in place.

 

 

The tube has been cut off...

 

 

I change collets and place the cut off hour wheel in the collet so that I can true up the cut off end.

 

 

Here is my new tube next to the hour wheel for the pocket watch movement. Test fitting and measuring shows that I have to enlarge the new tube I cut off and reduce the diameter of the pocket watch hour wheel slightly, so that I can mate the two tubes together.

 

 

I put the new tube into the collet, and run a reamer through it to enlarge the hole. I also slightly cut down the outside of the pocket watch hour wheel tube.

 

 

Test fitting shows that I have removed enough material and the new tube slips over the pocket watch hour wheel, step one is a success...only a dozen more steps to go

 

 

Cannon pin modification

 

Next up, I need to cut the top off of a H3 ETA Cannon pin, so that I can install it onto my pocket watch cannon pin.

 

Step 1, cut off the top of the ETA cannon pin.

 

 

After it's cut off, I true it up in the lathe as I did with the hour tube.

 

 

Here is the new modified Hour wheel installed on pocket watch movement. You can see the reason I need a new cannon pinion to accept my Fiddy hands, the existing one is much too small and too short...

 

 

The new ETA Cannon pinion tip is removed from the lathe so you can see what I am working with...

 

 

Measurements show me that I need to cut out the center of the Cannon pin tip so that it will fit over the pocket watch cannon pinion. The hole I need to cut into the bottom of the new cannon pinion tip measures out at 0.90mm...

 

 

Now that I have the new Cannon pin modified, I test fit it onto the pocket watch movement.

 

Success! perfect fit, so I epoxy the cannon pinion tip in place.

 

 

Fitting the movement into the case.

 

I didn't document these steps with photo's.

 

The movement was slightly too large to fit into the Fiddy case. I machined the inside of the case and enlarged it enough to fit the movement.

 

Once this was done, I test fitted the movement and as I hoped would happen, everything lined up perfectly, the stem hole lines up exactly with the case tube. Only problem is that my pocket watch stem is much too big...

 

Modifying the stem to fit my Fiddy crown...

 

Next challenge. Fitting my 1.20mm crown onto a pocket watch stem that measures a whopping 1.55mm...

 

 

Since the stem is hardened metal, I use a carboloy graver to turn it down to 1.20mm. Tempered metal will ruin my 1.20mm die, so I anneal the stem by heating it up with my butane torch. Annealing removes the temper and allows me to run my die over the stem and create new threads...

 

 

Big test, will the crown fit...yes, one more step out of the way...

 

 

I then installed the movement into the case, test fitted and trimmed the stem, and then discovered that the caseback was a bit too tight when screwed down.

 

I removed the caseback crystal, and machined the inner diameter of the caseback so that it would thread down without touching the new movement.

 

Hour and minute hands fit perfectly, what didn't fit was the seconds hand.

 

I had to remove and replace the seconds hand tube with a longer one that measured 0.17mm to fit onto my pocket watch movement. Once that was done, all the hands were installed and tested for alignment.

 

I lumed the dial and hands to match the Genuine Fiddy. This was done with pure Super Luminova C3 which is the same colour used on the Genuine PAM's (I have confirmed the colour against a genuine Fiddy and other genuine PAM dials I have had in the shop for repair and relume - ALL PAM's are lumed in pure C3, not a C3/C1 mix as some claim).

 

So what did I end up with...

 

Overall view

 

 

And the real reason for the mods...who can resist something so beautiful...

 

 

 

The movement was fully serviced before installation. The top pivot on the balance wheel staff was bent, I managed to straighten it out so it's almost perfect, but there is a slight wobble to the pivot (visible through the top cap jewel). This is causing a positional error of 4 seconds per day, so I will replace the balance staff with a new one and correct that issue.

 

Conclusion...

 

Reps have flaws, no matter how many mods we do to them.

 

With that in mind, and given the history of the "Fiddy", and my love of old pocket watch movements - not only for their timekeeping accuracy - but the fit, finish, and beauty, I thought it "Fitting to Fit my Fiddy" with something that I would enjoy looking at for a long time.

 

Knowing I have a 60+ year old movement on my wrist, with 21 Jewels and a Breguet overcoil hairspring, adjusted to temperature and 5 positions and that keeps time to within 30 seconds per week, is something I am proud to wear.

 

As well, I got to use and have fun practicing some of my watchmaiking skills.

 

Hope you like the results, and thanks for reading.

 

RG

[sconehead 5]

First time I've seen this here...great stuff...

[bob bean 0]

Outstanding!

What do you use to view these procedures whilst you work? A microscope camera fed to a monitor?

 

I love the Hamilton movements.

[mtt.tr 0]

i wouldn't mind a watchmakers lathe like real nice

[greg_r 81]

great writeup, but I can't see many here having the facilities to go to those lengths. Maybe John in a year or two

[bravehart 0]

Brilliant post , for a pure novice like me that gives a great insight into skill and dedication that you guys have

[dingle 57]

great post onze!!

[Novesh 0]

very nicee

[Member X 91]

Jealous of the skillz!!