Part 3: Hamilton Myron caliber 980 - Completing assembly and regulation

I managed to get a replacement click spring and install the click and ratchet wheel.

I'm waiting to install the balance assembly until everything else is assembled since it is somewhat delicate, and the less handling afterward the better.  So now we flip over to the dial side and install the cannon pinion on the shaft of the center wheel, in the center of the photo below.  The minute hand attaches to the cannon pinion shaft.

The hour wheel slides over the cannon pinion, so it gets a dab of oil.  (The hour hand attaches to the hour wheel, logically).  The brass dial washer is placed on the shaft of the hour wheel, I believe as a spacer between the hour wheel and the back of the dial.

Now only two parts remain, the balance assembly and its screw.  This took a long time to place.  At first it would not swing freely, and it would scrape against something.  I found one of the balance screws around the periphery of the wheel was partly unscrewed and was wobbling and rubbing against the pallet cock.  This may also have affected the timing of the balance, making it run slower than it should.

After tightening the balance weight it still would not run freely.  The balance wheel would swing only about 90 degrees for a while then stop.  I took it out and reinstalled, but still the vibration was too small, so I looked closer and found microscopic bits of lint or hair, about three of them stuck in the hairspring and the pallet, messing up the works.  

LESSONS LEARNED: 1) Keep the work area clean. 2) The longer it takes, the more gunk you collect.

Another issue I saw was that the hairspring is not perfectly centered, meaning that the coils of the spiral are tighter on one side than the other.  This is not something I have any business trying to fix at this point, so I left it at is.

Also, because of my less-than-deft handling of the balance, the hairspring had come out of the guide pins that keep it secure to the balance cock.  Once pressed between the pins the balance wheel could move freely and began beating strongly.  It was alive with a beating heart.

I don't have the instrument to measure amplitude, the degrees of rotation of each swing of the balance spring, but to my eye it appears to be well more than 180 degrees.  HandyDan says >200 is the goal, so I think it is enough to be healthy.  Here's a clip of it running:

I wound it fully to see how long it would run, and I was excited to see it running after 6 hours, then 12, then when I woke the next day, eventually running down after 25-26 hours.  After the hands and dial are attached the full run time can be measured.

I tried to regulate the watch timing with the movement out of the case, but it was so quiet that my makeshift audio rig would not pick up the ticking sound over the ambient noise in the room (mainly computer cooling fans).  So I decided to go ahead and assemble the face and hands to the movement because the regulator adjustment was easily accessed by removing the case back.  So regulation was left for the end.

Final assembly

Before installing the dial I cleaned the faces of the numerals very gently using just a toothpick dipped in cleaning fluid.  The dial was in pretty good shape as is, and I didn't want to take a chance of cleaning off the printing. So the only other thing to clean was the hands by sticking them in a piece of pith wood and taking them for a swim in the ultrasonic cleaner.

Honestly, I didn't notice a huge difference, but they did look good.

Next was to install the new crystal.  The old one (below, middle) was slightly scratched and probably could be polished, but I was able to get a new crystal (below, right) from G-S.  This crystal glues onto the front of the bezel.  It happened to fit perfectly, and maybe because I built so many model airplanes as a kid I managed to avoid getting any excess glue on the crystal. The old crystal is curved with beveled edges all around, while the new one is curved top to bottom and is probably more original.

Seeing the final product I think it went together pretty nicely.  The original dark crocodile strap happened to be the wrong width, 17mm instead of 16mm, and was jammed between the lugs so tight that I could not remove it without damage.The new Hadley-Roma genuine lizard strap was fitted, and I think the color is nice with the gold finish.  I had to steal the gold color clasp from the original strap, but it wasn't using it any longer.

Before and after.

Regulation

The last part of the process was to regulate the timing and test the run time.  I laid the watch in the case atop an old computer microphone connected to a laptop, then covered it with towels in an attempt to reduce ambient noise.

The Audacity freeware audio recording and analysis software allowed me to record the escapement ticking sound over a period of time and measure the period between a number of ticks to extrapolate the standard "seconds per day" accuracy rating.  I arbitrarily chose to record 100 seconds of ticking then used the cursor the compare the the time for 500 ticks.  (The 980 movement beats at 5 Hz or 18000 vibrations per hour or 0.2s per tick.)  With this rig I don't know how to measure beat error or amplitude, though there is probably some way to derive it by analyzing the waveform. (Note that in the waveform below the ticks are the big impulses while the shorter regular waves are 60Hz hum, possibly from the lamp on the table or a fan.)

The first test was with the regulator set to the 2S (slow) marker, and the result was about 80 seconds/day slow.  I moved the pin to 0, and the timing was about 27s/day fast (image above). The final adjustment setting was 0.5 Slow, and the result on the test was a pretty decent 7s/day fast.  (In the waveform the 500th tick occurred at 99.992s,)  It is desirable to set the watch to run a little fast rather than slow since a) they tend to slow down a little, and b) if you are early, you are on time.

Run Time

The final observations were to measure the run time on a full wind.  First I set the time to match my radio clock, which is always on the exact time to the second. (The 980 does not stop the seconds while setting the time, so there is about 30 seconds difference.)  After 38 hr 22 min, the watch is still dead on!  About two hours later, it stopped running, which says the run time on a full wind is around 40 hours.

I was probably insufferably pleased with myself at this point.  Not only does the watch look sharp if not exactly new, it is a functional timepiece and not just wrist bling.   I could not be 

happier with the results!

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.

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