Sunday, May 31, 2015

Part 2: Hamilton Myron, caliber 980 - Cleaning and assembly

Prior to lubrication and re-assembly, all parts need to be cleaned.  One common tool to use is an ultrasonic cleaner designed for jewelry filled with a cleaning solution.  I am using an inexpensive ultrasonic cleaner plus GemOro concentrate.  This process can require multiple passes, and finding the best way to contain the tiny parts during the bath is a challenge.

The stem of the watch was a particular issue because it was rusted.  Three cleaning passes were required to get the rust off the part.  Before and after:

Oiling the jewels was the next step.  For this I used Nye watch oil #140C, which is $11/oz.  This may seem expensive, but consider just one drop from the tip of a toothpick was enough to treat all the jewels in this movement.  The green tool is a watch oiler, which is just a needle device with a flattened tip, like the world's smallest spatula:

This went well other than knowing when you have sufficient oil on the jewel is very difficult.  

Next came greasing the mainspring and barrel.  For this I used Novastar Barrel grease ($16/oz). Put some grease on a folded piece of paper towel and run the length of the spring through the crease.

A little grease in the barrel itself applied by toothpick and I'm ready to wind and insert the mainspring:

Once wound, the spring is pressed into the barrel (round part at top) then enclosed by the barrel lid.  This is essentially the "rechargeable battery" of the mechanical watch.

Next came inserting the wheel train and plates that are the drive mechanism.  Aligning the top and bottom pivots for the four wheels was a breeze compared to the Princeton pocket watch movement. In the 980, only 3 of the 4 pivots are set in the (upper) main bridge and the fourth is in the barrel bridge (lower).

Tragedy struck at this point.  The two smallest screws in the movement hold a cap jewel to the dial side of the plate.  I successfully inserted one of the two, but the second one gave me fits.  I tried and failed several times, and the process ended when the screw snapped out from under the screwdriver and off the workbench never to be seen again despite at least a couple of hours of searching.  In the end I borrowed a compatible screw from a caliber 75 movement I had on hand and was able to continue assembly. 

But the hard lesson is being learned.  Working with tiny pieces is very, very difficult.  It takes steady fingers and patience (which I think I have), and technique (which I don't, yet).

Well, turns out I was a bit premature in my reassembly process.  The setting lever screw is sandwiched between the plate and the barrel bridge, so I had to remove the barrel bridge to insert the screw before assembling the setting and winding mechanism.  The setting lever screw is at about 3:00 on the very edge of the movement. 

I then replaced the barrel bridge and its three screws then flipped the movement over to work on the setting and winding parts.  All of the moving, sliding surfaces got some grease, and in the end it all worked as intended.



Next was the winding ratchet wheels, also known as the "click" because that's what makes the noise during winding.  Once again, a problem though...  While trying to insert the C-shaped spring into the click, the spring flew off into parts unknown, which is an interesting term in this context.  "Parts Unknown" is sort of a limbo for parts.  Not exactly gone, but definitely not found. <sad face>.  I need to find it or source a replacement spring to continue with movement assembly (SO CLOSE!).

Next steps:
  • Fitting the new crystal.  
  • Cleaning the hands.
  • Completing assembly.
  • Regulating (adjusting the timing) of the movement.
  • Final assembly.

Wednesday, May 20, 2015

Part 1: Hamilton Myron - caliber 980 - Disassembly

My brave, trusting sister sent me the Hamilton Myron she found on eBay as my first real victim project.  She had worn the watch for a few weeks before finding that though it kept decent time, it would run only about 8-10 hours on a full wind. As received it was actually in very nice shape cosmetically.

The case pries open through the back, which is stamped with the serial number S387212 and 10K GOLD FILLED.  The dial is very clean, and really does not need any help from me.


The caliber 980 movement (SN G509286) seems to be in good shape.  According to this link it dates to 1946.  This is a common movement and replacement parts are easy to find.  One thing that stands out is that the adjustment pointer is set well past "S", which makes me wonder if something could be jacked up with the balance or hairspring.  Reportedly, it kept pretty good time, so I am hoping a good clean and lube will bring it more into regulation.

My new/old hand lifter makes short work of the hands, then the dial is removed by loosening two retention screws in either edge of the plate and prying gently.

(Pretend I have gloves on in the second photo and don't tell Sis.)  

The dial side of the movement is a little grungy with some yellowish spoo (watchmaker terminology for congealed lubricant) at the top in this photo and some blackish stuff at bottom right.  

Now the fun begins.  Flip the movement dial side down and unscrew stuff, beginning with the balance.  This is removed first and returned last because it is fragile and can be damaged during the rest of the disassembly/reassembly process.  I am using a legal pad as my work surface and taking notes as I go to help me reverse the process and not forget anything.

Continuing to remove screws and parts, I manage to remove the ratchet wheel without stripping the left-handed screw that ruined my previous venture.  (He can be taught.)  

Next, the train wheels and barrel come out.  


The barrel houses the mainspring which stores the energy to power the watch movement.


Sure enough, the mainspring is tired after about 70 years.  A fresh mainspring will uncoil to a bigger "?" shape, so this one needs to be replaced.

Last in disassembly is removing the winding and setting mechanism including the stem and other parts that function when one pops the crown in and out to set the time and wind the watch.  Here are all the movement parts laid out in order of removal, L-R, top-bottom.

So far, so good.  Nothing broken, nothing lost.

Next up...
  • Cleaning movement parts.
  • Lubricating all jewels and moving parts.
  • Greasing and installing the new mainspring.
  • Reassembling the movement.
  • Adjusting the timing.
  • Assemble dial, hands, etc.
  • Fitting a new crystal to the bezel.
  • Polish the bezel and case.
  • Fitting a new lizard strap.
Update: 21-May-2015

I received the new mainspring and crystal for Myron.

My First Watch Project - Princeton Pocket Watch