How to Make an Airsoft Mock Heartbeat Sensor

Have you ever thought that your airsoft gun was missing something? Well why not a heartbeat sensor! It adds the perfect touch of futuristic flare to your airsoft gun you've always wanted! Although this particular one doesnt actually sense heartbeats, it can still amaze your friends and give you something fun to build and use. This heartbeat sensor is from the popular game Call Of Duty Modern Warfare 2. Im sure many of you have seen it.

For this project, you will need to get the following:
Empty milk carton
Altoids Tin
Small 1 1/2 by 2 cm metal hinges
3 LED lights (Colors of you choice, i chose 1 white and 2 blue)
Silver permanent marker or sharpie
Spraypaint
small insulated wire
on/off switch
Small Energizer A23 battery
Scotch tape (blurry kind, not the clear kind)
Rail mount
2 Magnets
2 small metal plates

(Optional items listed below for add-on)
Small RIS rail (airsoft)
Durable peice of scrap plastic
Small screw
screw (size depends on what airsoft gun you have and if you need this add-on)

First, start out with cutting out the top of the altiods tin with a dremel. Dont cut all the way to the edge of it though. Take the milk carton and cut a rectangle that fits in the top of the tin. Make the Heartbeat sensor design with a silver sharpie on it and place it in the top as shown.

Here comes the fun part. Drill a hole in one of the sides of the altoids tin big enough to fit your switch. open your altoids container up and fill it with the LED's, wire, battery, and switches shown in the diagram. Make sure positives are on positives and negatives are on negatives. If not, the circuit will not work. Point the LED's upwards. If they are too bright, cover them with the scotch tape to dampen the light.

Tape over the "screen" on the heartbeat sensor and paint it the color of your choice.  Drill some holes in the side of the altoids tin for the hinge. if your right handed, drill them on the right. if your left handed, drill them on the left. Sew on your hinge and screw the other side of the hinge onto your rail mount. Glue a metal plate onto the altoids tin as shown in the picture and place a magnet on your rail mount where your metal plate will connect to it when swiveled out. Last, take your other magnet and glue it on the front of your altoids tin as shown. this will keep it in place when you close it. You may need to add a metal plate on your gun for it to attatch to when closed.
Note the front magnet on the second picture.

If you have the JG m4 or any other gun without a long side rail, you may want to stick around for this extra add on that will add for a better effect. Take your small RIS rail and your scrap piece of durable plastic and screw them together forming an "L" shape. Drill a hole large enough to fit the size screw you will need to mount it to your gun as shown.

You're finished! have fun with your new (mock) heartbeat sensor!