Make Your Own Wristwatch and Dosimeter from Metro Exodus

Materials and gear needed

• Steel rods
• Lumber
• Rechargeable digital watch assembly - custom build
• Rechargeable battery charging module
• RF detector and emitter
• Perspex or acrylic sheets (matt and clear)
• Templates for the parts
• Metal files 
• Screwdriver set
• Tube shrink wrapping
• Pliers
• Sandpaper
• Mini lathe
• Soldering kit
• Electrical wires, resistors, and soldering gear
• 3D printer
• CNC machine
• Laser etcher

With all the parts and gear in hand, it is time to get on with the build.

Step 1: Make the main watch body

The first step is to secure a metal cylinder into your lathe. This will be used to make the main watch body. Machine it down to the correct thickness for the diameter of the watch you want. 

Once complete, machine a hole through the center of the cylinder. Progressively widen the hole, as shown in the video, using larger and larger drill bits, as needed, to hollow out the piece. 

Continue working the inner bore of the cylinder until only a thin wall remains to the cylinder. With that complete, begin to add grooves and other details to the outside edge of the metal cylinder. This will be used to make two main parts -- the actual body of the watch and another to make clasps and other details. 

Once complete, cut the piece loose from the cylinder, as needed.  With that complete, machine the one half of the piece, as shown in the video.

Next, assemble your machined pieces, and drill a series of holes around the outside edge of the smaller of the two parts using a CNC machine. 

With that complete, CNC a series of clips as shown in the video. Cut each part loose from the main ring using pliers, and tidy them up using metal files.

Once done, drill and countersink a hole in the middle of each part. 

Thread all the drill holes you've made as well. 

Next, machine a small bracket to be mounted to the outer edge of the remaining metal ring. Drill some mounting holes, countersink them, and then thread them to receive some bolts. 

Glue the piece into place on the outside of the metal ring, and then extend the drill holes into the ring walls. 

With that complete, mount the bracket to the ring using suitably sized bolts as needed. Next, sink two holes to the vertical parts of the bracket and file off any barbs as needed.

Rinse and repeat for a second bracket directly opposite the first. These will form the main watch strap mounting points.

With that complete, drill a series of holes around the center of the main watch housing. Thread them as needed. 

Step 2: Continue working on the main watch housing

With the main watch body now more or less complete, mount your metal ring into a lathe, or CNC machine, and machine a groove on the inner surface of the ring, as shown. 

Once done, machine a small lozenge shape on one side of the top of the ring and drill a hole through one side of it. This will form the main charging connector for the watch later.

Insert a small double-holed plastic washer into the cavity, as shown. 

With that complete, take a smaller rod of steel and machine it into a series of small hollow bolts using your lathe. Thread the ends of the bolts as needed. These will form the main button holders for the watch.

Once done, mount them in place on the main ring, and then make three smaller diameter rods to fit inside them. These will form the main buttons to the watch.

Step 3: Make the rear faceplate

With that complete, take a piece of metal sheet and mount it into place to your CNC machine. Then machine out a stylized metal circle to match the main ring of the watch. 

Create the design of the piece however you like. 

Polish as needed and then spray paint black (or any other color you'd prefer). Sand off the topmost layers of paint to leave the recessed details painted black. 

Secure it into place at the base of the main watch housing ring. To do this, you will need to mark out, drill, and thread a series of bolting points into the ring and the rear faceplate. 

With that complete, soak all the parts in thick bleach and leave for around 10 minutes. This should give the exposed metal a darker aged appearance. 

With that complete, boil them until the metal has a rich tarnished appearance as shown in the video. 

Step 4: Make the main faceplate and add the watch gubbins

With that complete, take a piece of perspex or plastic, and CNC machine a circle to the same dimensions as the main watch face. 

With that complete, polish the perspex until it is perfectly clear. Place the perspex into place on the watch housing, and mount it into place using a machined retaining ring. 

Secure the pieces into place using several of the mounting clips you made earlier. 

With that complete, take your digital watch assembly, and insert it into the center of the watch main housing. Ensure that any buttons line up with the holes and buttons you machined earlier. 

Obviously, ensure the display is the right way up. 

If required, add any protective plastic layers below the delicate electronics of the digital watch. With that complete, insert and wire up the rechargeable battery for the digital watch. 

With that done, grab your soldering iron. 

Take two lengths of wire (use a red and a blue one), strip off a small length of the insulation to one end of them, and then twist the wires. Add some lengths of heat shrink insulation, and wire the ends to a blue LED light.

Heat the shrink wrap to seal it and then wrap the entire end with some blue insulation tape.

With that complete, feed the wires through the hole adjacent to the buttons on the watch, leaving a small length to bend the wires and affix the LED light just below the nearest watch strap mount.

With that complete, solder the other ends of the wires to the main circuit board of the LED watch. 

With that complete, remove the plastic washer for the rechargeable battery connector. Trim it down as needed, make or use some small plastic washers, and machine some connector pins to fit. 

Assemble the piece as shown below. Reattach the assembly to the main watch housing. 

With that complete, solder some lengths of wires to the pins, and solder them in turn to the LED watch circuit board. With that complete, solder the rechargeable battery to the board as well. 

Add a small strip of insulation tape to hold the battery into place on the IC. With that complete, test the digital watch to ensure it is working properly. 

You should see a series of zeroes appear. Then test the buttons to check the watch's functions like setting the time, date, turning on and off, etc. 

With that complete, take your new watch straps. Sand them down a little to give them an aged look.

Then add the mounting pins to the watch straps, and attach each end of the strap to their mounting points on the main watch body. 

With that complete, mount the compass to one of the straps, and close the watch up using the backplate. 

Step 5: Make the charging base for the watch

With the watch now more or less complete, we can make the charger base for the watch. Grab a piece of wood, and CNC the shape of the base. 

With that complete, secure a sheet of metal, and CNC the metal plates for the charging base. 

With that complete, we can move on to making the charging part of the assembly. 

Create a matching set of charging pins for the base to connect to the other pins in the watch. These will need to be spring-loaded.

Drill a hole where needed in the charging base to mount the charging pins. Mount the charging pin assembly into the base.

With that complete, cut a small slot to one side of the charging base. It should be big enough to fit a USB charging port through. This will be used to connect the main power cable for recharging the watch's battery. 

With that complete, assembly a micro switch to the left-hand plate of the charger. Next solder wires to the main charging pins of the base. 

With that complete, wire up and solder together the main charging circuit including the switch and capacitor, etc. 

With that complete, assemble the recharging base for the watch as shown below.

Step 6: Making the dosimeter

With that complete, the next step is to make the dosimeter. Take the 3D plans for the parts needed and 3D print them.

Once complete, cut off and sand down any bridging and support mold excess as needed. 

Depending on the 3D printing method chosen, complete any post-printing steps required -- like treating with UV light, etc. 

With that complete, grab another piece of perspex and machine out the base parts of the dosimeter. Once done, mark out the position of the circuit boards, and drill mounting holes into the perspex as needed. 

Next, mount the RF receiver board and speaker to the base as needed. 

With that complete, add the main housing for the dosimeter to the base plate to enclose the circuit board. Then feed the speaker into place and cover it with its 3D printing housing. 

Once done, take an old analog voltage indicator. Dismantle it to reveal the needle, and remove any labels that may be in place. Trim down its mounting plastic to fit inside the main "dosemeter" display housing. 

With that complete, disassemble the dosimeter and spray paint the main 3D parts black. Leave it to dry, and then apply a layer of rust orange or copper over the top. 

While the paint is still slightly wet, use some cotton buds to work the paint to give the piece a truly aged and used feel. 

With that complete, machine a small length of clear perspex to make a short cylinder. Attach the RF receiver to one end, and then insert it into the main body of the dosimeter. 

Next, add some PVA glue to the plate of the meter, and glue on a printout of the dosimeter. 

Cut and add some small pieces of clear plastic to simulate the glass panels, where needed, and then wire up the circuit board to its battery. 

Add LED lights to the main display, and wire them up to the circuit board as well. 

With that complete, begin the final assembly of the dosimeter. Complete the circuitry, and then mount each of the main 3D printed housing pieces as needed. 

Make and then glue any other perspex pieces needed too for the housings. 

With that complete, make a simulation AA battery for the bottom of the dosimeter. Machine a short cylinder of metal and then make a series of large wooden washers for either end. 

Glue them all together, add a strip of wire, and then insert them into the "battery" receptacle of the dosimeter. Secure all parts into place using bolts as needed. 

Once done your DIY dosimeter is basically complete. There is one final optional step you can do, but it really isn't necessary. 

Take some sheets of plywood, and CNC the various parts to make a carry box for all the parts. Then laser-etch a design to the lid and assemble the entire box. 

With that complete, you can now safely store your DIY watch and dosimeter inside. 

Now all you need to do is strap the watch and dosimeter on your arm and pretend you really are in the game! Well done you.

If you enjoyed this project, you might like to make something a little more practical. How about your very own working wind turbine?