Here we have the raw billet of stainless steel, which is roughly 25mm thick (or 1 inch).
A very rough, and only temporary marking of where the bezel area will be parted off.
Since the billet is sawed off, both faces are not square to the sides, and if machined as such would not allow to repeatedly hold and get perpendicular surfaces on the lathe.
So the billet is turned flat on both surfaces in respects to it's sides. Here you can see how off one of the faces is.
Further turning the face flat, it is a rather slow process as the unevenness creates a hammer effect on the tool bit as it cuts. Thus cuts need to be light.
Almost finished with the surface.
One face is turned flat.
Getting the sides square to the face.
The billet was turned around, and the procedure repeated.
A billet with perpendicular surfaces.
Marked off where the slab of billet will be cut off for the dial.
Making a center hole, to open a temporary interior opening.
Boring the interior of the dial space.
After opening the interior to 30mm, I proceed to turn down the outside of the ring to 45mm.
This creates a lot of dangerous swarf, it is dangerous as it must be continuously removed, if not it can catch in the spindle and potentially be thrown at one's face or body.
The billet ready for the bezel ring to be parted off.
The billet is placed again on the lathe, and the bezel area is begun to be cut off with a parting tool.
Cutting goes very slowly and after a good 25 minuetes of slow progress the bezel portion is parted off.
Due to the way I cut this (making small lateral cuts as the piece is parted), I have to face off the front bezel ring.
Next I mark where the case center will be parted off.
Then I spot drill a center hole guide. This is necessary so that during initial drilling, the drill does not 'walk' out of center.
These small diameter drills, if not guided by a center hole, bend easily and bore out a non-centered hole.
The center hole is progressively bore with larger diameter drills.
Finally a 20mm diameter drill is pressed in.
Then with the tool bit a 28mm hole is opened.
Work moves slowly to take out swarf which quickly builds up.
Parting off of the case body.
The very last section of the parting off is done with a saw, and the piece cut of is 'caught' with the tool bit.
The case body portion is faced off so that both it's sides are paralell.
The bezel and case body billet portions ready for the next operations.
The interior space of the case is milled out. There are two diameters needed to be machined.
Opening the interior is a slow proces as the stainless needs to be slowly bored away.
Here one sees that the chips gum up quickly and have to be removed often. If one one risks that the swarf picks up other pieces and they are thrown around by the chuck.
The face to be turned here, which is the back / bottom part of the movement is painted black to see where one cuts more easily.
The recess for the exposition caseback is cut to depth first.
Then the outside bevel area is marked off.
Then the slow process of facing into the piece begins. This is the bottom of the lugs profile.
Hard grooving to remove material sligtly quicker.
The outer bottom angle of the lugs.
The bottom of the case.
Checking finish by placing tool bit to see reflection (see left of tool bit).
Turning is slow as this is what happenes with every cut.
Further grooving.
More grooving.
Deepening the groove, for the crotch of the lug.
Creating a slight fluted back bezel with a specially formed tool bit ground for this purpose.
The back of the case, with initial finishing to be finished once the case sides are machined.
The case is then turned around.
The movement seating is turned to diameter.
The top of the movement sits on this first wider step.
A recess for the mainspring barrel has to be milled out before further machining. Here I am centering the rotary table on the jig boring machine.
After centering the rotary table, the case is fitted to the table, and that is also centered so that the movement of the case is concentric with the movement of the rotary table.
I use an edge finder (a device that wiggles until becoming perfectly cylindrical once the edge of the piece if found) to measure furst area of cut.
The shaft moves concentrically, and hence the edge of the inner case portion found.
I mill out an arc with an end mill. Milling is done wtih many passes as a jig borer is done for veritcal hole drilling, and not milling operations. Too deep of a cut could cause vibration and the tool bit to get caught in the piece- potentially runing it.
The arc for the mainspring barrel to move freely is milled out.
The piece is placed back in the lathe, and this time the front of the case is turned.
A slow process of cutting large amounts of stainless steel from the front starts.
The main measurement of the top of the lug's downward taper is dune. It is turned to exact depth to get the correct lug angle.
Then i cut the recess for the snap on bezel. This is slow work as the special cutter warms up very quickly and causes wear.
Cuts are short and shallow, and stopping of lathe and removal of swarf is done.
Snap on groove for the bezel is done.
Positioning the cutter to the angle.
Starting the cut. Chatter (or vibration of tool bit) has to be at a minimum, if not the cutter digs into the piece (due to the large cutting surface) and can ruin the piece).
Further progress on the taper.
More cutting.
The taper of the outer top most part of the lugs is cut.
Preliminary finish on the top of the lugs.
The case is then removed and held from the inside and the outer diameter reduced to measure.
With a specially formed cutter the start of the outer downward curved bevel of the lugs is started.
The bevel is cut in progressive stages, moving the cutter to arrive at correct curvature.
Further cutting of curvature.
Further cutting.
After various hours of slow cutting, the curvature is arrived.
The case is turned around, and now the bottom of the lugs is finished.
Here too is another curve, with a differen angle that is slowly cut.
Further cutting and positioning of the cutter to get the desired angle.
Last cuts.
The profile of the lugs.
Bottom of lugs.
Top of lugs, further finishing needs to be done after the case sides and lug interiors are cut.
Some initialreflections.