• Battery Micro Hot Air Gun

    Morning.Star12/09/2018 at 09:10 1 comment

    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...


  • Battery Micro Soldering Iron

    Morning.Star12/09/2018 at 08:31 0 comments

    This device had rather a long evolution...

    Trying to solder up my LED cubes required some extensive lateral thinking to get around the lack of a temperature controlled needle point for soldering the backs of these horrible new components.

    It can be done with a decent iron which I dont have. Well, I do, its an Antex with a needle point tip, but it isnt TC and as a result just boils solder off. Its also a little large for 0402, I can do 0805 with it.

    The problem of overheating the solder is still an issue. To make these tiny blobs the solder has to be quite cool, just over its melting point. Conduction soldering is already a technique I use, as copper does it so well, so I adapted the idea and wrapped a thick shaped wire around the iron to transfer only a percentage of the heat to the soldering point... This works really well.

    I havent shown it here, but you can actually control the amount of heat going to the tip with a bead of solder on the original iron tip, touching the copper. Big bead, hot tip. No bead, cool tip. ;-D

    However its not the easiest way of doing things...

    I gave up smoking and bought myself a series of gadgets to replace it with, vaping is a good alternative for me. I even got into building my own hardware, but its messy and fiddly, worse than roll-ups. So I got myself a decent tank and PSU and am done with that nonsense lol.

    The hardware is highly useful though.

    I insulated a copper tip with Kapton and wound it with a 2-Ohm heater coil. From experience with vaping coils I know this wont burn the power supply up.

    All the same, I cautiously set the power low to begin with. Just as well really, 5 volts 2 amps proved to be more than plenty, and a couple of seconds on the button brings that up to soldering temperature pretty quickly.

    It IS a bit of a mess though, and I also want the PSU for other things, so I wont build it into the iron.

    Instead, it'l plug in.

    I'm now in the middle of moving, so I havent cased anything yet, this is as far as I got.

    Copper conducts heat so well I wont be able to use that for long comfortably, so it still needs a cotton boot over the handle. It wont need much, the iron only heats during use, and the power supply has an auto-cutoff after 10 seconds to prevent it accidentally depleting the battery in a pocket accidentally.