The other day I enjoyed a good can of casserole for lunch and later in the evening looking at the casserole can I thought to myself, I could make a drum receiver out of it and so I pursued the idea and went ahead it with!:)
I firstly measured the diameter of the can which was 100mm and calculating the circumference it worked out to be 314mm which dividing by 32 lines would give me around 9.8mm distance between holes and wanting the distance to be at least 10mm I opted for 30 lines instead which worked out to about 10.5mm distance between holes. I decided this time to opt for horizontal scanning instead of vertical as I thought suspending the can upside down off a DC motor would me be most ideal so I went for the TeKaDe 30 line horizontal scan format which suits perfectly for this tin can TV. Having the width of the picture at 10.5mm and going for the 4:3 aspect ratio the height calculates to around 7.85mm, so the picture works out to be very very tiny in size for this can!
I made a 30 line strip template and wrapped it around the can as precisely as possible, sticky taped it in position and using a needle I drilled 30 holes in the tin can and I must say I was surprised how easy and effortlessly the needle drilled through the can! I then precisely as possible drilled a hole in the centre base of the can so it can be mounted on a DC motor.
I next needed to make the can dark and matte as possible to prevent light reflections so I roughed the shiny surface of the can and spray painted it matte black on the outside and inside.
Next I had to choose a suitable DC motor to drive the can, so from a junked CD stereo system I used one of the little DC motors and mounted it onto a piece of bakelite and mounted the can to the DC motor.
Then I made the LED bank which consisted of 4 LEDs, as I had low quantity of brighter LEDs I chose to go funky and use 2 yellow LEDs and 2 green LEDs as I couldn't be bothered going to Jaycar. I then made the hood with diffuser on the end and attached it to the LED bank. On light up the mix of coloured LEDs looks kind of like the floor lights on Saturday Night Fever
Next phase of construction is to mount all the pieces together. I used a piece of wood for the base, nailed some wood pieces on the sides of the base to support the bakelite beam with motor and suspended can mounted on it. Underneath I initially cut a plastic avocado dip container base as a bowl to stop the can from wobbling too much on rotation and glued it to the base, unfortunately the can kept catching the edgers and getting stuck so I abandoned the idea and snipped the bowl down lower than the can. I glued the LED bank to the bowl so the can is positioned over it and the LED bank covers the area to be scanned.
In the final construction phase I hooked up the DC motor speed control and LED drive circuits and screwed them to the side wood pieces holding the motor and drum assembly. Being a lazy bugger I decided to once again use the DC motor speed control and LED drive circuits from my very first cardboard mechanical televisor once again.
Now for the testing. I plugged my MP3 play to the LED drive circuit and with MP3 encoded TeKaDe 30 line format videos onboard I gave the tin can televisor a burl and getting the motor to the right speed we have picture wooooot!!!:D As expected it is very tiny almost microscopic so a magnifying glass is needed especially for detailed videos. Also the colour is of a funky blended mix of green and amber which I think looks cool! The picture of course is a bit distorted due to the general off accuracy drilling of the holes in the side of the can and wobble of the can due to the hole in the base slightly off centre but otherwise good considering those factors. So the dang thing works!:D
I have made a video series on the construction of this tin can TV but have yet to edit and upload them to YouTube but when I do I will post the links, so stay tuned for them. In the mean time here's a bunch of photos of the construction of the tin can TV along with a sample telerecording I made with my 90s camcorder: