The case starts as a solid billet of brass to be machined.
Outer diameter of case being turned.
This was then cut into a smaller billet roughly the thickness of the center-case body.
Drilling to make preliminary interior hole for holding the case from the interior.
Opening the hole.
Case billet is held from the inside, and the rough shape of the underside of the case (bottom of lugs) is shaped.
The billet is turned over and the top curvature of the lugs is performed.
The billet is placed on the milling machine (here in a jig borer as the milling machine was not acquired yet) to mill the outside of the lugs.
Once the outside contour of the lugs was milled (which involved milling arcs that are all in relation to the center of the case, so that the lugs don't come out uneven), a special cutter was shaped to cut the underside of the lug.
Here in the cutting process of the special under lug shape.
The shape cut, and to be further worked on the lathe.
An initial rough cleaning of the milling marks is done with a filing die on the Linley jig borer.
A mounting bracket is machined to accept a case holder on the lathe's vertical milling slide.
At this point, I had no easy way to machine a clean inner lug area, so I used a slitting saw and a case holding jig to cut sharp interiors.
Had to fashion this jig to be held in the Leinen tool holder for the Hardinge lathe.
Cleaning the interior of the lug. The case moves vertically to present to the blade.
Then further cleaned the interior of the lug area with a specially formed fly cutter.
This work is very slow as I have to make sure that the lug diameter is not off-center, thereby possibly ruining the case.
The case requires a lot more work for finishing.
Opening the interior of the case to start the threading of the top and bottom for the bezels.
Further cleaning of the underside of the lug. Cuts have to be taken very lightly if not the torque risks distorting the lug shape.
Further cleaning of interior of case. Here, due to the thinness of the case, the cuts have to be taken very lightly. Making the whole process very time consuming.
Set up the manual threading attachment on the lathe (using a special tailstock spindle and attachment).
Centering the case on the 4-jaw chuck so that it runs concentric, and the threads are true to the case curvature.
Centering and testing the thread cutting with a piece of brass.
The interior bottom threads for the case back are done. The same is done to the front of the case, for the top bezel.
The front and bottom bezels are now cut.
Turning the interior of the back bezel.
The back bezel rough turned.
The front bezel is started.
The bezel is parted off.
Front rough bezel.
The front and back bezels to be further machined, finished, and threaded.
The case received a significant amount of hand work with files and many different grades of sandpaper, and then polishing.
To start the work, I color the case to see more easily where the file is working and how the shape is changing.
The top bevel of the case is being hand filed here. Work has to move slowly, since it can easily ruin the case.
Marking out the depth I want of the bevel on the case.
Further view of the case bevel during work.
The side of the case has to be cleaned of machining and filing marks
Further intermediary steps in the case finishing.
After many hours, a near finished case is done. More final finishing is done at the very end when all other details are done.
Another view.
In order to better finish the interior of the lugs, I built a die-filing attachment. This allows very precise and 90-degree perpendicular filing. It is run by the lathe.
Cleaning up the interior of the lug area.
Finishing achieved in the interior of the lugs, using a fine-grain file.
The sharp interior of the lugs. Often contemporary CNC machined lugs have rounded interior lug areas, which is not apt for every case style and unsightly.
Case with bezel, after working the bezel.
Cutting the hytrel gasket pocket for the sapphire crystals.
I have machined it so that the gasket is nearly invisible, so that it looks like the traditional pressure-fitted pocket watch crystals.
The back bezel crystal fitting.
Back crystal fitted.
Now, I am moving onto the crown tube support, that is necessary because the case sides are less than 1mm thick, thereby, extremely fragile to tortion.
Centering the outer portion of the crown supporting tube. I pre-drilled a hole for the inner portion of the tube that will be soldered to the case.
Using a fly cutter, set at the diameter of the case, so that the outer portion of the crown tube will sit flush with the case.
Scallop machined.
And sits flush to the case side.
The outer diameter of the tube is reduced and parted off in the lathe.
The part needs further work before being able to be soldered to case.
Faced off so that its outer portion is flat.
Interior tube that connects the outside to the case is machined (here the hole for the crown stem portion is drilled).
The outer diameter of the tube is turned and then parted off.
The tube is held in a toothpick.
Then it is pressure fitted to the outer portion of the crown supporting tube.
The hole for the winding stem is found by measuring the depth of the winding gears in the case, and then, centering the movement so that the crown is at the proper midway point. This is a very delicate operation that can lead to serious errors.
After the hole is drilled, the crown tube is fitted to the case.
And soldered. It is left longer, which this is then cleaned up.
The time setting pin hole is now drilled, by holding the case in a jig, and held at the correct angle from the center, so the pusher will run true to the pin being pushed.
A loot at the space available for the time setting pin, given the case back is put in place.
Machined a new time setting in, that is then parted in half, to give space to the back bezel.
A time setting pin is introduced, and it too, needs a special shape given the lack of wiggle room inside the case.
The time setting pin and time setting screw in place in the movement (tensioned by the spring).
Now machining the 1st version of the winding stem, that would later be rejected as it created too tight a winding action. Checking the cutter shape (not finished here) on the optical comparator.
Checking shape with the gear that it will engage.
Made a jig to be able to sharpen the tungsten carbide cutter. Here also helpful in measuring when on the optical comparator stage.
Grinding the shape with the Agathon M125 carbide cutter grinder.
Further forming the shape with my hands and continuously checking with the optical comparator.
The cutter placed in the fly cutter, next to the gear that the new winding stem will mesh with.
Setting up the steel in the optical dividing head on the jig borer. Testing that the steel piece to be cut runs true.
Hardening the new winding stem.
Tempering under fire to a blue hue.
A jig is made to test if the winding stem winds as needed. This jig was made prior to the crown tube being fitted, and the stem hole drilled at the depth that was calculated for the real hole.
The movement is tested in the aluminum jig to see if it's a correct fit.
The hole for the stem is drilled in the jig borer.
The test winding stem is tested.
Here we jump to the final version of the winding stem. With the solid bronze winding stem block fitted to the interior of the movemement.
The block has a recess so that it doesn't interfere with the tensioning spring.
The new stem, with the small pip that is supported inside the movement.
The stem held by the crown, and as it looks before the 3/4 plate is placed on the watch.
This is the final version of the crown that was made (out of about 6 total that were made).
The interior of the crown recess (it is a 2 part crown) was rough drilled, and then it is temporary soldered onto a steel rod for machining.
The outer 'onion' shape is machined by hand, with a center line rod left on purpose so that the piece can be centered for further machining.
The shape is compared to that one designed via the optical comparator at a 10:1 ratio.
A profile cutter is shaped so that the correct number of teeth can come out, and it is as desired by the drawing.
The contour is shaped with a pantograph, where the outer profile is traced onto the crown.
Each rib is indexed, and individually milled.
This is then, further machined. After cutting the ridges are very bright and sharp.
Here the interior portion of the crown, with the threaded sleeve for the stem is machined
It is parted off.
An old center drill is used to hold the two parts for soldering.
The stem then is placed in this specific purpose made jig to machine the outer pip off.
The outside of the crown is cut and the form shaped.
After soldering the inner part to the onion crown, lots of fire scale (discoloration) was present and this had to all be hand filed and polished.
The crown previous to final finish.
Here are some of the other crown shapes made in order to decide on final crown choice. Here ribbing with a knurling tool.
Two part crown ready to be soldered.
Placing the silver solder with the flux in the crown.
Soldered with heat.
One crown time.
Another crown with large ribbing grip.
Another with thick ribbing, milled on the milling machine.
Fine grip.
Angular grip.
Final crown shape.
