Having finally given up on my Hoover which needed its filters cleaning after every room (seriously!) I found a cheap (relatively) Dyson online at Comet (the animal at £200 is way below Dyson’s own price). I have just been to www.dyson.co.uk to register it and from there drifted across to http://www.jamesdysonfoundation.com/ to have a look at ways they are encouraging engineers. They seem to do stuff with schools and all sorts so if you have young (potential) engineers around you may wish to take a look.

One thing that was a bit depressing was that the downloadable diagram for making your own cyclone was a JPG in a ZIP file. What kind of engineering example is it to put a lossy compression like JPG inside a lossless compressed container (ZIP)? Hardware guys, what do they know?  Once you have downloaded (and unziped!) the diagram you can make your own cyclone but it still doesn’t explain how it extracts the dust. Wikipedia it is then… http://en.wikipedia.org/wiki/Cyclonic_separation