Step 1: Stuff you Need
- a small bottle and cork (mine came with my metalic beads...score!)
- some tiny metalic beads (Some are conductive, some are not. anything silvery usually is, they need to be tiny to flow well and make good overall contact. A decent substitute would be teeny balls of tin foil.)
- paper clips or a similar stiff bit of wire
- a thicker gauge of copper wire, I used house wiring
- some hook-up wire
- some glue or some acrylic paint
- small needle nose pliers
- a soldering iron
- a pin (safety pin, sewing needle)
- a small container
- a turn of the century mood
Step 2: Empty Two Bottles
Now make a little paper funnel and pour a small quantity of beads into each of the two empty bottles, a quarter of the volume should be fine.
Step 3: Make The Contacts
Take your sewing needle and 'pre-drill' two holes in each cork by carefully pushing the needle through the cork, work slowly, the corks are fragile and brittle.
Once your holes are pre-drilled, you can push your contacts through.
Use the paint to seal things up and lend some support to the cork. I did this later, now would have been a better time, learn from my mistakes, and do this step now. (you will see that in the next step, mine are not yet painted).
Once the paint is dry, go ahead and solder some leads to one of the contacts for each switch.
Step 4: Connect it all Together
At this point you have two tilt switches, you could stop here and use them just as you would use a mercury switch. I wanted it to be bi-directional so I attached them together.
Luckily there is a nice groove in the bottle shape to facilitate this.
Use your copper wire (the thicker gauge) and wrap around one of the bottle necks with a turn and a half. The groove accepts the wire perfectly and getting it snug was easy.
Line the other bottles neck up, but invert the bottle, and wrap a turn and a half around this one as well. Your two bottles should be securely attached together.
Finally you can bend your contacts. Bend them so they come in contact with the copper wire.
Solder them to the copper, solder a lead to the copper, and your sensor is complete!
Test it out with your multi-meter. Set your meter for a continuity test. Attach one lead from your meter to the copper wire, and another to either of the other leads and give it a tilt.
Tilt it one way and the beads in one bottle should bury the contacts inside the bottle, thereby closing the circuit for that side. Tilt it the other way, and the beads fall away from the contacts breaking the connection. The opposite effect will be happening in the other bottle.
Add two more (or even more than that) and you have an effective multi-directional tilt sensor for dirt...erm...bead cheap.
Share and enjoy.