You will need:
- Some sort of pad/base (I used an old hdd shelf - this is especially useful because it has cooling vents however this may be small for many laptops - a stripped down desktop access hatch could work well, providing you strip the plastic caser)
- A PC fan, I used a 12v which is fairly powerful (<9v means you can run it on usb)
- An old phone charger/adapter that has the same voltage as your fan (I literately just pulled this from a pile of cables)
(a usb cable will work for a fan using less than 9v, i will include instructions for this in brackets at steps where i used the AC adapter)
Take your old fan and cut and strip the live and neutral wires (this is usually the red and black). If you have an earth wire (green), just isolate it by cutting it down, it's not needed.
After this cut and strip your charger/adapter. (or in the case of a usb cable, you should strip the outer cable to see 4 further wires. You will need to strip the black and red and should just isolate the green and white)
Now you should twist and cover in electrical tape/ solder the live and neutral wires. If you dont know which is which (as in my case as the adapter is black and white), just twist two together and test if it powers the fan. If not, you have it the opposite way round and should just switch the 2 and do the above.
You now have a working fan coupled with an AC adapter (or usb cable).
The next step is to mount it to the underside of your pad.
First work out the airflow direction so the airflow is directed away from your "pad"
Your best option is to use superglue/epoxy however i am currently using electrical tape until my ordered epoxy arrives. (I wouldnt reccomed electrical tape - it falls off too easily)
Plug in and put your laptop ontop and you are done.
If you are interested in something cooler, you could incorporate the usb development of this with a usb hub on the underside of your "pad" and add LEDs or other peripherals (perhaps usb storage devices). With a simple 9v pump, it is possible to make this into a water cooling system or even mini AC unit if you have the chemicals (CFCs from a fridge for example, not that I would reccomend transferring this as I have no experience in this).
If you buy a sheet of metal (<£10 on ebay), you could quite easily bend the material into shape (perhaps circle the metal back on itself in a rectangular shape, which allows for aeration through the sides whilst looking sleek) for a much more proffessional look