It's Over!

Whew!  I've been ill with a cold all week.  Bad timing, because this is the week when we take our CW21 certification exams!  Today I finished the final task.   It's quite a grueling test because of all the different components which are as follows:

1. Theory
2. Quartz overhaul
3. Micromechanical tasks (restaffing/turning a barrel bushing)
4. 7750 Chronograph overhaul

Overall I feel like my performance was up to standard, but we'll have to wait to see what if any weaknesses the examiners find in my work!

I have now cleaned out my desk and packed up all my watchmaking gear.  I'll head back in once more to say my farewells to everyone at the school and pick up the results from my final exams.

It's been a extremely busy but fulfilling two years here in Seattle.  I've made lots of new friends, got to experience a new city, and obtained a skill that will be able to support me for years to come.

I'd like to extend a big thank you to my watchmaking instructors Elaine and Erik.  I would also like to thank the program coordinator Shawn for her help in getting through these last two years.

I'll continue to post interesting watchmaking factoids and oddities as I enter the professional watchmaking world, though I'm sure I'll find reason to post much more rarely.  Thanks for following me on this journey!



-Andrew

Finish Line!

As of today, I've basically three weeks left of time at both the Watch Technology Institute and in Seattle itself.  Two more weeks of class which will be spent practicing for the CW21 test which will be administered in 3 weeks.  After the CW21 all that is left is to clean out my desk and say farewell to my instructors and classmates.

I've secured a very good watchmaking job in Dallas, Texas earlier this month and will be leaving Seattle almost immediately after leaving school.  This leaves these few short weeks to tie up any loose ends and get packed!

I'll probably post once or twice more with updates before my move out of Washington.  But thanks for following along with me during these last two years.  Time fades away!

Case Brasswork Complete

As I posted previously, I've been working on making a watch case out of brass.  I have finally got around to finishing all of the forming and drilling.  I have decided to go with a through-screw configuration.  It looks great, like something off of a submarine.  All that remains is to send it off to be plated, then to push the chrono pushers and case tube into the case and install the crystal.

If it's back from the plating place by the time I leave school I'll post pictures here.

Ready for plating!

Broken stop-lever

This week I have started my final quarter of watchmaking education at North Seattle College here in sunny Seattle.  The primary focus of this last few weeks are to focus on finishing up remaining projects and final practice for the AWCI CW21 exam in August. 

Today I worked on a Rolex 3035, which is the previous incarnation of the 3135 that is found in many modern men's watches.  The watch had stopped entirely and I had to figure out why.

In this situation it was fairly obvious as there was something directly blocking the balance rim, the stop lever (also known as the hack) had broken.  In the 3035 the stop lever rides on the set lever.  When you pull the stem out into the setting position the set lever pivots, pushing the stop lever up where it lightly contacts the balance rim stopping the watch.  This allows one to easily set the watch to the second when changing time.

The hook at the back of the lever in this watch has broken off and the part was sliding freely, blocking the balance regardless of the position of the stem.  Fitting a new part confirmed that the slot where it rides and the set lever and in good condition and the old one has most likely broken due to fatigue because of improper assembly.  With the part being replaced the mechanism is once again working as designed.

Broken!

The new part with the old, broken part

RM90 machine repair

One of the school's RM90 cleaning machines stopped working.  I volunteered to fix the thing.   The problem was that the retract assist spring was broken (for how long I have no idea).  This put extra strain on the drive shaft that moves the cleaning platform up and down.

Due to this additional strain, the roll pin that tied the shaft to the gearbox had disentigrated.

To fix the problem I needed to remove the lifting wheel the unbolt the motor from the housing.   Once the supply wires were labeled and removed I could disassemble the motor and gearbox assembly.

The remnants of the original roll pin were hammered out, then I installed a new 3mm pin using a vice to drive the pin home.   Finally, after reinstalling the motor I lubricated the mechanism and installed a new assist spring.

The machine is once again in working order, hopefully my inexpert repair lasts the test of time.

 

Opened gearbox

Broken spring hangs from the upper right, the lifting wheel is disconnected on the left side

Output cog with remnants of the old roll pin waiting to be hammered clear

The new pin installed

Machine reassembled with new spring, ready for testing

SAWTA 4

Today I passed my SAWTA 4 exam.  I'm now a SAWTA certified watchmaker!  The remainder of the year will be spent doing projects and prepping for the CW21 exam at the end of the school year in August. 

Metric reaming

Got to use the new set of metric reamers today to increase the inner diameter of a pully so it can be fixed to the shaft of a lathe motor.   It's provides a very smooth finish and required little effort on my part thanks to the mill's automatic worm feed system. 

The milling machine

Closeup of 8mm reamer

Case Ring

In the runup to SAWTA 4 I have had extra time during preparations, so I have continued work on the brass chronograph case.

I have turned a one inch piece of pvc conduit into a suitable casing ring for the Omega 321.

Now comes the turning of the case.   The main challenge with this is going to get the workpiece centered properly for the final dimensioning.  The 3 and 6 jaw chucks are not suitable for maintaining perfect concentricity.   I will probably have to use a centering scope and the 6 jaw chuck with some shimming to get close enough when working on seperate sides of the case.

Case Progress

Brass Doughnut

Today I took my brass blank, which essentially started as a thick puck of brass.  I then squared off the ends, reduced the diameter a bit and then started hollowing out the middle.  Lots of work to go, but I won't press on with forming the rest of the main case until I finish the casing ring which will decide the final inside dimensions of the case.

Making Case 2

Here is the basic layout for the proposed case.  The outer diameter may have to be reduced to make it easier to install pushers and the stem.  I won't be using this as a engineering guide, but as a proof of concept.

Making Case

 

The Omega Seamaster with the 312 movement I made the minute jumper and hammer springs for last year is lacking a case.  I have overhauled the watch and it's running well, but it's sad to see such a nice movement sit in a plastic tray.  The dial and hands are in okay condition, so I'm going to attempt to turn a brass enclosure for the movement on the lathe and install a case tube and pushers for the operation of the watch.  This will consist for a brass cylinder with a crystal pressed into it, the back will be screw-down with a display back.

So far I've modeled the watch dimensions in CAD and will begin working on the design for the case.  Then the difficult part will be turning the components on a lathe which is really too small for the job.  Stay tuned!

Finished Escapement Model

Finished line draft

Today I finished the CAD version of my escapement.  This was done using Google sketchup.

Drafting

This week we are doing a drafting module in class.  The old Chicago School of Watchmaking program has a 'drawing of the Swiss lever escapement' chapter so we are following the steps outline in that program to complete a reproduction of a standard Swiss lever.  In class I have been working with traditional drafting equipment: pencil, compass, square, protractor, etc. 

However I also have been working with CAD software which makes the process much more accurate and much cleaner.  See the pictures below.

Here is the CAD layout for the escape wheel

CAD escape wheel finished.  Next step is to layout the fork, pallet and roller.

Power Flow

As a watchmaker it's important to understand how power is transmitted in a watch.  This enables one to more easily troubleshoot problems that may arise in the system.

A common question that comes up on tests in class and in certification exams deal with how power is transmitted in a watch.  Sometimes it's difficult to create a mental picture of these systems as they are condensed and typically inhabit 2 sides of the watch.

For visualization and study I have constructed a flow chart which is helpful in understanding the movement of power in the system.  This particular chart is for a 2824-2 and watches of similar design sans the automatic and calendar systems.

7751 Chronograph Components Assembly

Today I finished the overhaul of the 7751.  It just takes a bit longer than the 7750 because of the extra parts on the dial side.  Overall the process took around 5 hours to complete.  These practice sessions are important because we have to service 7750 chronographs for both the SAWTA 4 and CW21 testing.  Next week I will be working on a 7750 installed in a Tudor case that has been thoroughly mucked up by my instructor.  I will try and post results.

Chronograph base components technical documentation

Here is the cam jumper and cam installed.  The cam synchronizes and controls the functions of the chrongraph.

Here the lock and the ratchet wheel driving wheel have been installed

Chronograph bridge, installed

Here is the operating lever spring, lubricated and installed.  This is what pushes back on the chronograph buttons when they are depressed

Here is the operating lever, notice some more of the white grease on the end where it interacts with the cam

Testing the operating lever and its interaction with the cam

The next phase

Here the chronograph and minute counting wheels have been installed along with the tiny oscillating pinion which is the disconnect between the watch and the chronograph mechanisms

Here is the clutch, reversing wheel and reduction wheel installed

The automatic bridge, installed.  The hammer has also been added before the bridge is installed

The long curved thick spring on the left side is the hammer spring, it puts pressure on the return to zero hammer

Here is the depthing engagement between the oscillating pinion and the chronograph wheel.  The depth is controlled by the clutch and its eccentric, here depthing is slightly shallow as you want about 2/3 engagement

Increased engagement slightly, enough to have good positive contact but not enough to increase friction beyond tolerance

Finally the minute counter jumper spring must rest perfectly on 2 teeth of the minute counter when the hammer has been activated.  This prevents the minute counter hand from moving when the hammer is reset

Time to flip the watch over and work on the dial side components

The driving pinion is pressed on.  This is the friction point in the watch that allows the hands to move freely during setting but in normal operation is still moved by the mechanism

Here is some more of the motion work, the minute wheel and free cannon pinion have been installed

Here are the hour counter return to zero components and wheel

Here is the day corrector and its spring

Here are the 12 and 24 hour wheels installed

Finally, on this level, the calendar driving wheel

The penultimate page!  This is all jumpers and correctors

Date star wheel installed with the date corrector

Here are all of the jumpers and springs.  These index the day and month dials, along with the moonphase indicator

The final page of assembly, some final plates and the indicators

Here are the 3 indicator wheels installed along with the moonphase platform and combined maintaining plate

Dial is installed, hands are installed

Using a hand press to apply subdial hands

Completed movement, ready for casing

Cased and finished