Following on from the soldering iron, I decided to try my hand at an airgun. It seemed simple enough, and I had the stuff laying around.

I figured, blow cold air down a bit of tube and over a heater coil, how hard can that be? It turned out to be a lot harder than I thought.

Attempt The First

So far so good. @Daren Schwenke was quick to notice I'd attempted to get as much compression into is as possible, figuring the nozzle would cause back-pressure.

Actually, in the end the weak-ass motor I chose for its ability to run on 5v was a poor choice. It wouldnt even turn the cage.

However, it looked so much like a whistle I was tempted to do this.

Worlds first breath-powered phone charger... Not how that was intended to work at all :-D

Attempt the Second

Building on Darens comments, having tried this himself and discovered a spiral technique using string to get the housing the right shape, I redraw it in Inkscape and reprinted.

I was a bit more thoughtful about the clearances as well this time. Same motor, it spins up ok, just not if its stalled to begin with...

But it turned out to be completely useless and didnt have enough huff to move dust or scraps of paper.

Attempt The Third.

I also figured I was probably using the wrong materials.

...Probably the best materials in the world. XD

Seems to be working so far... The trick is not to liberate too much aluminium at once ;-)

Much headscratching over how not to burn my pinkies or my pocket on the nozzle. That brass tube is deliberately rather thick to retain the heat so there isnt so much hysteresis from the coil during use. Its designed to get hot and stay that way, unlike the iron.

So, a shroud...

Which is cooled using some of the cold air from the fans. Ahah! :-D

A little bit of aesthetics, something I'm not really big on with a functional build (for some reason) and its a runner...

Until I have moved and completed the power supply it remains untested for now. Wont be long, just over a week and I'll have a whole brand new workshop to build...

...