How to Fabricate a Custom Watch

This instructable will describe the process of making a custom watch.

Overview:
Watch Case
- design 3D computer model
- print plastic model via 3D printer
- cast metal model of watch case via lost wax method
- additional assembly
Watch Face
- design watch face
- hand craft work
- install pre-made movement
- additional assembly
Wristband
- hand craft work
- additional assembly

Materials:
-casting bronze
-sheet metal
-leather
-watch crystal
-watch movement
-watch stem
-watch crown
-watch hands
-watch band pins (spring-bar pins)

*watch supplies can be purchased online from websites like http://www.esslinger.com/
*casting bronze and metal supplies can be purchased online from websites like http://www.riogrande.com/

Equipment:
-3D printer
-centrifugal casting facilities (or other lost wax metal casting facilities)
-oxy-acetylene torch
-dremel/drill/rotary tool
-various jewelers metalworking tools (saw, files, pliers, tap and die set, etc)

Step 1: Design and Print the Watch Case

Design your watch case in whatever program you find easiest. I went to school for animation so I know/used Maya, though it would probably be more accurate to use something more CAD oriented.

Considerations:
1. There are various sizes of watch crystal to choose from. Model accordingly and leave a lip for the crystal to rest on
2. The watch face attaches to the other side of the lip. Leave enough room for the cannon pinion of the movement and hands between the crystal and the face.
3. Make an indent for a corresponding tab on the watch face to secure into.

Print your model in plastic via 3D printer. Since I used the Cupcake CNC I built, the surface wasn't very even and additional clean up was required to achieve a smooth finish. Getting your model printed professionally may be an easier option

Step 2: Casting and Finishing the Case

- Attach sprues to the plastic model and invest it into a mold for burnout and casting.

- Clean up the metal cast and add finishing accents. Drill a hole for the watch stem, four on the back to tap threads into (to attach the back plate), and one hole in each of the lugs to secure the watch band pins

- Make a backplate with holes corresponding to the tapped screw holes in the case. It may be easier to drill the holes in the backplate first and then mark where the corresponding screw holes should be drilled into the case.

- Apply any patinas to the case if desired.

- Attach the watch crystal via epoxy or adhesive of your choice.

Step 3: Construct and Assemble the Watch Face

-Design a watch face and construct it. I made mine out of thin sheets of bronze, copper, nickle, and sterling silver hand-sawed out and torch soldered together with rivets to mark the hours. Make sure the face is thin enough that the hands will be able to fit on the pinions through a hole drilled in the face.

-Attach the movement and hands to the face without the stem, place the face in the case, then attach the stem and crown through the hole drilled earlier. Secure the movement and face with epoxy or an adhesive of your choice.

-Close up the back with the back plate and screws. You can either use an o-ring or some silicone caulk to seal the back to be water resistant.

Step 4: Fabricate and Attach Strap

-For the strap, I sewed together a couple of strips of leather. Note that you will need loops for the spring pins to attach through. The buckle is a piece of cast bronze made in the same process as the case. Pierce a hole in the strap for the buckle to secure through.
*Alternatively a pre-made strap can be purchased

-Attach the case to the strap via spring-bar pins