A rather simple project featuring an LED turned on by a tilt switch. I got the idea from seeing similar instructables but i felt like i wanted to make my own improved version. Since valentines was coming up a decided to shape my project like a heart made of plexiglass and have it turn on/off depending on which side of the heart it was leaning towards.
The heart turned out about 6.5x6.5 cm.

What you need:
A computer with CAD and CNC mill (Depending on the shape that you want to make and the material you choose to work with. If you are going to do some really simple shape you can manage without this)

Tools:
Soldering iron
Sandpaper
Phillips screwdriver

Materials:
1 Battery (C2032 3V)
1 Red 6mm LED
1 Tilt switch
2 Resistors (16 ohm)
Some wire
2 M3 Bolts with nuts
2 pieces of 100x100x6 mm plexiglass
(optional) some heat-shrinking tube

This probably cost me around 20$-30$ but i bought enough parts to build at least 30 of them so building one will probably cost you around 5$-10$ since single parts are usually more expensive than packs of them. The two most expensive parts are the switch and the battery.

It does not take much experience but basic soldering skill and basic CAD knowledge will make it a lot easier.

I used http://led.linear1.org/led.wiz to find out which resistor to use.

Step 1: Shaping Your Figure

An important step in this project is to plan the layout of your shape. I wanted to make it as small as possible so i bought the components needed and measured them so that i knew how i should place them. At this point it is also a good idea to make a sketch of how you are going to solder your circuit since it will have a large impact on how you have to shape your figure.

Step 2: Shaping Your Figure 2

This is the shape i came up with. A base and a lid held together by a pair of nuts and bolts (not in the picture). I used CREO elements to do this but any other CAD program should do. Note that the base and lid are simply the same piece but mirrored in this picture, when i later "printed" it I didn't carve out space for the components in the lid (exept for the tilt switch) since they could all fit in the base part.

If you are confused by what i just said please have a look at step 4 where both halves are printed.

Step 3: Printing the Shape

Im afraid that i cannot say to much about this since i had help of my teacher when printing this. It might be for the better since every program probably has its own way of "translating" a CAD model.

Note again that this is the lid and how it doesn't have any space for the Battery, LED and resistors.

Step 4: Printing Your Shape 2

This is what the shape came out like from the CNC. I used a small knife to remove some loose plexiglass around the heart and a small saw so remove the tabs that hold the heart in place.

Step 5: Soldering the Circuit

In order to make the circuit fit the shape perfectly i soldered one piece at the time starting from the tilt switch. I simply put the parts i was going to solder together in the heart and used a pair of small pliers to bend the wires to fit perfectly together. It ended up looking like in the picture (note that i used some heat-shring tubing to cover the soldering and that one o the resistors are covered by it, i don't really think that it is necessary to have though since none of the wires will, probably, connect and short-circuit). I also had to sand down the 6mm LED a bit since the gap it was supposed to fit in was only 4mm deep.

The tilt switch i got was a non-mercury one which from what i can tell is composed of a metall ball rolling inside a tube to turn on/off. It does flicker a bit if not completely still. If you have access to a mercury tilt switch i would probably recommend using that insead (it is hard to come across those since electronics may no longer contain mercury).

The lower picture is of the first time i assembled the heart, it still needs some sanding to say the least.

Step 6: Sanding

This is the part where you will be having regretful thoughts.

All of the tabs have to be removed as eel as the entire outside of the heart. BE CAREFUL not to scratch the front and back of the heart since plexiglass is really easy to scratch and it will look really ugly. I recommend using a smooth sandpaper just to be extra careful.

Also take cars of the plexi, note that there is a piece of corrugated fiberboard protecting the heart from scratches from the vice.

Once i was done sanding the edges and removing the tabs i washed the pieces in water to remove some of the dust from the sanding.

Step 7: Finishing Touches

Finish your masterpiece by filing off your bolts if they are too long. I used the edge of a round file (probably my favorite tool) to remove the excess parts. Note that i put a piece of paper between in order to protect the heart against scratches.

Step 8: Done!

Done! You are done and it should look something like this. I hope you enjoyed the project. This was my first ever instructable so if there is something you are wondering, want to compliment or complain about please do not hesitate to leave a comment!