this is my first instructable so i decided to enter it in the pocket size comp
its quite simple to make and mine cost nothing
you can use it for small craft/hobbie work and use it to cut through foam/polistyrene and any other small soft foam
.

all you need is
a small piece of ply wood
mdf
guitar string
9 screws
2 pins
disposible camera circuit
9v snap
resistor
wire

tools
soldering iron +solder
drill
pliers
screw driver
saw

Step 1: Cut the Wood

this here is just the basic construction of the frame
first cut the ply wood to 2 bits 10 cm long and 1.5 cm wide and 0ne to 5 cm long and 1.5cm wide

then cut the mdf to a 5 cm square you will be needing 2 of these as well

Step 2: Frame

assemble half of the frame but keep a piece off the mdf off
and screw or glue together

Step 3: The Circuit

for this step you will need your soldering iron and solder
your camera circuit and some wire
a pair off pliers also can help
first desolder the batterty contacts and solder the resistor and snap on
then take off the capaciter and solder two other wires
and on the wire butten on the back you will need to put a blob of solder on that

Step 4: Screw on the Next Piece of Mdf

leave the wires hanging out and put the two front wires on the pins 1.5 cm froim th top
twist the guitar string on to the pin really tight
screw on the last piece of mdf
connect a battery and then you are finished