Can-phones : The whys and wherefores
This Can-phones piece is devoted to anyone who has been stuck inside the house with the kids and needs something fun to do with them instead of more TV or Angry Birds.
It’s been several years but I decided to see if I remembered how to do this and to put those empty coffee tins to good use by making a pair of can-phones with my 6 year old.
Safety, safety, safety
The coffee tins I used are a brand that has no sharp edges; some of them do and as such are completely unsuitable for kids to place to their mouth or ears and use as a phone.
Some of the prep work here was done using a model drill .. gloves, goggles and kids at a distance please and once done disconnect the drill from the wall socket and put it away.
You will see in the photos I used the model drill sanding head to grind down the sharp edges created by drilling thru the can.
As I was doing this I was explaining to my 6 year old at each stage .. he gets safety and was thrilled when I let him wear the safety goggles. It’s all good fun.
For those of you unfamiliar with can-phones the idea is two cans with holes through the center of the base and a string tied through the hole. When the string is taut between the two cans, one of you speaks into their can and the other hears by holding their can up to the ear.
The taut string carries the vibrations of the speech along it and the cans “transmit” and “receive” the sound. If you are a physics buff and have a better explanation that works for kids, have at it.
How To Do It
Here are a bunch of photos detailing the steps we took to make our phones:
Raw materials and drilling the holes.
Grinding down the sharp edges from drilling
Threading and knotting the “phone wire”
Talking and listening on the phone.
Everything after grinding down the sharp edges was done with the Little Guy and he had a lot of fun doing it. He’s also at a curious age so he had a lot of questions throughout about how it worked.
I’m afraid there is no bluetooth, sync or apps to be had for this model but on the plus side battery life is indefinite. Enjoy.