17 February 2009
Continuing my experiments with air compressors, this week I built a 35-stage turbine. After stalking eBay for a while, I got my paws on a box of 40 computer fans for $25. Stack them up, seal the joints with homemade play dough, solder a couple of power buses, and that's it. The result is an impressive machine. Each fan is fairly weak, but when connected in series each one builds on the pressure of the previous one.
That's the theory at least. In practice the device fails to live up to its potential due to the embarrassingly large gap between the outside of the blades and the enclosure. Thus air never gets to the full pressure, it just leaks back to the previous stage. I need to look at ways to shim that gap closed.
In the mean time, the turbine is excellent at inflating my large guest bed. Previously this was a chore which rapidly led to light-headedness. The only catch is that one has to watch for periodic eruptions of play dough, as bits of the dried sealant break off internally and get ejected like the spray from a wood chipper.
This weekend I was planning on flying over San Francisco onboard the airship Eureka. Unfortunately high winds prevented her from leaving the hangar. Looks like Airship Ventures have learned from history. Such is life with an airship.