Introduction: The Can Phone
Put a telephone in a pair of tin cans. Because you can! A tribute to the 'Two Cans on a String" phone you made as a kid.
My first Instructable and I will toss it in the Green Science Fair Contest as repurposed old parts.
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Step 1: Materials
Old slimline telephone
Spool of white 24-guage stranded wire
Hot glue gun
Needle nose pliers
Soldering iron and solder
Pencil and paper
Warnings: Metal-working tools can cut you. Soldering irons are hot. Hot glue guns are too. Flying pieces of metal can cut your eyeball. Wear safety glasses.
Step 2: Disassemble the Phone
The handset contains the keypad which will mount in the base can, and also holds the speaker and microphone which will be mounted in the second can. Keep the coil cord. The handset will likely have a couple small screws to remove, hidden under the paper label. Use a big persuasive screw driver to pry open the handset after the screws are removed.
Step 3: Cutting Things Down to Size
Remove the keypad from the handset so you can cut the handset to size. The pushbuttons will likely fall out. Watch where they land.
Make a template by taping a piece of paper to the front of the handset. Use a pencil to make a rubbing. You will later hold the paper template on the can to help size the opening you will be cutting.
Cut the handset down to size so it will fit inside the base can. Don't make your cuts too drastic. You need the support offered by the various riser pegs. A mini hacksaw works well when tin snips are too unweildy.
Step 4: Cutting Metal
Use a sharp screwdriver and a hammer to make your preliminary cut.
Needle nose pliers are useful for enlarging the opening. Once the opening is large enough to accomodate the tin snips, make diagonal cuts to the corners. Make cuts perpindicular to the opening you have drawn. Fold the tin under along the line. A regular set of pliers can be used to bend the metal in a straight line (pinch the metal at the line, bend up to weaken, bend down and under along the same line, pinch to flaten the fold.)
Step 5: Wiring Considerations
Cut four 24-inch strands of 24-guage wire. Label both ends of each wire. One will be the "red", one will be the "black", one "green", and one "yellow". Your labels can be paper tags held with scotch tape, or a code or your choosing (one mark for red, two marks for black, etc.) You need to label the wires because you will be twisting them into a "string" and you need to know which is which when you are done twisting.
Don't get carried away with the length of the this 'string'. The longer it is, the more resistance, and the lower the volume you will hear when you use the phone.
Punch a hole in the top center of the base can. The hole should be just large enough for the four wires. Gather your four wires and pull the bundle through the hole. It may be easier to pull one at a time. Label both ends.
Step 6: Off-Hook Switch
Disassemble the base. It will be held together with screws. The base contains the Off-hook switch, ringer and phone line jack. It sometimes has a metal weight to give it some stability. You can reuse it for the same purpose.
I did not have a solder sucker, so I cut the Off-hook switch's six-lead base right across the legs, and soldered exensions to it. This was necessary because the board with the switch was too big to attach comfortably to the can top. I also wanted to mount the switch on the edge of the can so that the top can could sit on the switch (to go off-hook when not in use).
The switch has to be glued to the side of the can and its location is such that it is hard to reach. I put a small dab of hot glue on the side of the switch and attached a screw driver. I then put a large amount of hot glue on the other side of the switch and positioned it until the glue solidified. The screw driver twisted loose easily due to the small amount of glue used.
Step 7: Finishing
Cut a hole for the phone jack. This can be done with sharp screw driver. Then use a hefty knife blade or needle nose pliers to enlarge the hole.
Glue it all together with hot glue.
Glue the speaker and microphone to the handset can.
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