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The materials I
use for making things have changed a lot since I started 40 years ago.
Through my teens and twenties there were wonderful industrial surplus
shops in London. After going into the Observer to deliver and edit my
cartoon strip, I would often fill my cycle panniers with beautifully
made motors, cam timers and other bargains from Lisle street or Edgware
Rd.
One by one the surplus shops closed, but for me their place
was taken in the mid 80s by the local scrapyards, particularly Sackers
of Ipswich, which received all the scrap from British Telecom research
labs. Complete machine tools, elaborate industrial automation machines,
endless entertaining boxes of mysterious electronics. My friend Rex used
to go to the scrapyard every day.
In their turn, the scrapyards closed down. Scrapyards are now so efficient and full of ingenious recycling
machinery that no one is allowed in when they're running.
But I'm now making a living by building contraptions instead of by drawing, so I
often buy new stuff. The cost of new industrial stuff soon mounts up, and doesn’t
have the appeal of using ‘free’ stuff. Although I to look back on the
industrial surplus shops and scrapyards with fondness we have entered a new, different age of technological bargains –
consumer electronics and E-bay. I increasingly buy stuff direct from Hong Kong
and China.
These are some of the consumer parts I use in my clocks and
arcade machines. Before I start I have to apollogise for not
giving details of product models – they seem to change every 6 months,
so the ones I’ve used will already be unavailable by the time I finish
writing this. Don’t worry though, the changes are usually just
cosmetic – the underlying technology changes much more slowly.
MOTION SENSORING OUTDOOR LIGHTS
About £10. In place of the light, connect it to any other mains
operated device – disorientate burglars by switching on your lawnmower
or starting up a CD player (see below). Its also easy to change motion
sensors into beam sensors by sticking a tube on the front to make them
‘blinkered’.
WASHING MACHINE SOLONOID VALVES
At about £5, these are at least ten times cheaper than any other valve
of a similar flow rate. They work just as well with air as with liquid.
There are two slight drawbacks – first they need a bit of space (the
input and output connections are different and both quite clumsy and
bulky) – second, they won’t switch low pressures, which I often find
frustrating – but hard to grumble at the price.
CAR WINDSCREEN WIPER MOTORS
£5-£25 from a car scrapyard, £70-£150 new. Fantastically powerful,
long-lasting and quiet. I have one on my clock on Southwold pier which
has been switching on and off every one and a half seconds for over four
years – despite being in the salt air and nor waterproofed. DC motors
have an enormous starting torque, a huge speed range, simply adjusted by
the input voltage – 12 volt car wiper motors work slowly at three
volts but still have useful power and are completely silent. Use diodes
to reduce the speed (.7 volts per diode) - not resistors (Under load,
the motor has little resistance so the resistor just gets hot and the
motor doesn’t move).
MEDIA
PLAYERS
In my arcade, I now use compact flash card 'kiosk' media
players. No moving parts, so they are generally more reliable, though it
took a while to find a good solution. I've been through several and
I'm currently using the Brightsign HD120 (which does HD video).
PERSONAL COMPUTERS
I have tried using PCs in my machines, but they are always hassle.
They are far to complicated for the simple stuff I'm trying to do do.
When they go wrong it can be really hard to get to the bottom of the problem.
My Expressive photobooth still runs with a PC, but I've probably spent
more time keeping it running than all the other machines in the arcade
put together.
ARDUINO
MICROCONTROLLERS
About £20 for a main board and another £5 for a shield board.
I've been using Arduinos to send serial data to displays, media players
and ticket printers. The great thing about them is that they are open
source. There are sample programs of almost anything you might want to
do online, and if you get into trouble you can post a question on a
forum and it gets an answer very quickly (within two minutes in my most
recent case). I'm still very slow at the programming language C++, but I
am getting better. I went on a weekend beginners course which was brilliant. It really gave me the confidence and
motivation to start experimenting by myself. The other breakthough was
finding a shield board. An Arduino nearly
always needs some input and output circuitry for any real application.
This was possible with veroboard, but wires kept falling out. Everything
is just much quicker and more reliable with a shield board.
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