Don’t throw out that old printer! Not that you would, but even if you’ve already scavenged it for parts, you can use the shell and the rollers to make a rock/coin/what-have-you tumbler. If your printer is part scanner, it might end up looking as cool as [th3_jungle_inv3ntor]’s. You’ll have to laser-cut your own arachnid to supervise from above, though.
Somewhere between having an irreparable printer, being inspired by another tumbler, and the desire to make a mancala set for his sister-in-law, [th3_jungle_inv3ntor] was sufficiently motivated to get out his hacksaw and gut the printer. He used the main paper roller and its motor to do the tumblin’, and a smaller roller to help accommodate different jar sizes.
Aside from adding those sweet blue LEDs, he wired in a toggle switch, a speed control pot, and an LM317 to govern the tumbling rate. Unfortunately, the rocks in [th3_jungle_inv3ntor]’s town are too soft and crumbly, so he can’t make that mancala set after all. But hey, (almost) free stuff tumbler.
No dead printers lying around? If you have a drill and a vise, you could always make a tumbler that way, and nothing is compromised but the peaches jar.
We must admit to wondering how Adafruit’s [Becky Stern] gets anything done with those fingernails of hers. They’re always long and beautifully painted without any chips, dings, or dents. As it turns out, she uses UV gel nail polish. It’s much more durable than standard air-dry polishes, but it requires UV light to cure. [Becky] bought a lamp to use at home, but it’s very bulky and must be plugged into the wall. She knew there was a better way and devised her DIY UV mini manicure lamp.
She really thought of everything. The open source 3D-printed enclosure includes a small compartment in the top for cuticle sticks, emery boards, and tweezers. The Li-poly battery is rechargeable over USB in conjunction with Adafruit’s PowerBoost 500c. The lamp itself is made from 30 UV LEDs and 100Ω resistors. [Becky] lined the inside of hers with silver sticky paper to help distribute the UV light evenly.
You know, this can also be used to erase EPROMs or to cure small DLP 3D prints. Do you have another use for it? Tell us in the comments. Introductory and partially hyperlapsed video after the break.
[Shane] needed a UV exposure box to help speed up the process of making PCB’s at home. Not wanting to spend a few hundred on one, he decided to design and build his own, using a planter box!
Why a planter box? To be honest, it was simply the first opaque container [Shane] found, so he decided to base the design around it. Inside the planter box are two 15W fluorescent daytime bulbs which output a similar amount of UV to normal sunlight. A mirror is placed below them to help reflect all the useful light out of the box. A pane of glass was cut to fit on top of the planter box, giving you a nice surface to place curing PCB’s on.
All in all, it’s a pretty simple and inexpensive method to make your own UV exposure box. We’ve also seen it done before using UV LEDs and IKEA picture frames — just make sure you don’t start tanning your hands while you’re working!
[Stephen] doesn’t have the luxury of readily available hot water in his apartment, and since he’s just renting he didn’t want to buy one of those instant powered units, so he decided to go ahead and build his own!
He’s using a submersible 1000W immersion heater in a 2.5 gallon water container which has been mounted high up in his bathroom to let gravity do the work for actual shower. It’s not quite an instant shower unit as the water needs to heat up like a kettle before being used — this takes about 4 minutes to hit the optimum temperature.
The current shower head installed drains the tank in about 2.5 minutes, which might not seem like much time for a shower, but let’s be honest — we could all probably cut back our shower time and save some water for the environment! Something one of our Hack a Day Prize entries is hoping to solve through music!
Some people aren’t too crazy about the rush of RFID enabled credit & debit cards, and the problem is, you don’t really have a choice what card you get if the bank sends you a new one! Well if you really don’t like this on your card for whatever reason, it’s pretty easy to disable.
[James Williamson] recently got a new debit card with RFID technology — the problem is it was messing with his access card at work, the readers would beep twice, and sometimes not work. He decided to disable it because of this and that he didn’t really use the tap to pay feature, nor was he completely convinced it was as secure as the bank said.
Since these RFID chips use antennas made of copper wire, he could have just started slicing his card with a knife to break the antenna — but, since he has access to a CT scanner, he thought he’d scan it to figure out where everything was.
Simply make a small notch in the edge of your card, or snip off one of the corners. This breaks the antenna and prevents power to the chip when held near a reader — though if you don’t have access to a CT scanner you might want to double-check next time you buy something!
Now there is another side to this — maybe you actually like the whole tap to pay thing, well, if you wanted to you could get a supplemental card, dissolve it in acetone, and then install the RFID chip into a finger ring for Jedi-like purchasing powers!
Jacob’s Ladders are a staple experiment in any self-respecting mad scientist’s lair — err, a hacker’s workshop. And why not? High voltage, arcing electricity, likely more than enough to kill you even — brilliant! But in all their awesomeness, Jacob’s ladders really aren’t that complex.
In [Kevin Darrah’s] latest tutorial he shows us how to make one out of a transformer taken from an oil furnace. Why exactly does an oil furnace even have a high voltage transformer in the first place? They’re actually used as the ignition source, like a pilot light!
The one [Kevin] has is a 110VAC to 10,000VAC transformer, which puts out about 20mA (probably enough to kill you). And to turn it into a Jacob’s Ladder, you’ll just need a two long stiff wires (copper is a good candidate). The wires are closest at the bottom where the transformer can easily arc — this arc then ionizes and heats the air causing it to rise, carrying the arc with it. As the arc continues up the ladder it gets longer and longer as the wires become farther apart, becoming more and more unstable until it breaks. When this happens the arc forms again at the lowest point of resistance — the bottom.
My introduction to electronic manufacturing was as a production technician at Pennsylvania Scale Company in Leola PA in the early 1980’s. I learned that to work on what I wanted to work on I had to get my assigned duties done by noon or thereabouts. The most important lesson I had learned as a TV repairman, other than not to chew on the high voltage cable, was to use your eyes first. I would take a box of bad PCB’s that were essentially 6502 based computers that could count and weigh, and first go through inspecting them; usually the contents were reduced 50% right off by doing this. Then it was a race to identify and fix the remaining units and to keep my pace up I had to do my own desoldering.
It worked like this; you could set units aside with instructions and the production people would at some point go through changing components etc. for you or you could desolder yourself. I was pretty good at hand de-soldering 28 and 40 pin chips using a venerable Soldapulit manual solder sucker (as they were known). But to really cook I would wait for a moment when the production de-soldering machine was available. There was one simple rule for using the desoldering station: clean it when done! Failure to do so would result in your access to the station being suspended and then you might also incur the “wrath of production” which was not limited to your lunch bag being found frozen solid or your chair soaked in defluxing chemicals.