Want some fancy ice for your next cocktail party? You can try to find spherical ice-cube trays but you won’t get the kind of results seen here. It turns out the trick to this isn’t how you freeze the water, it’s how you melt the ice.
[Brendan O’Connor] started this project after seeing an ice mold that could make beautiful shapes rather than just cubes. But the price tag was $1400. If he could make his own at a hackerspace we’d bet that would pay his membership for an entire year!
The concept is pretty simple. The video after the break shows the mold he was trying to recreate. It’s two hunks of metal with a shape milled into them. The mold is pre-heated, then an oversized hunk of ice is placed between the blocks. The heat melts away the parts you don’t want, and leaves a perfectly shaped ice orb in between. Gravity is responsible for pulling the mold halves together as they slide along some machined rods.
With a big hunk of scrap aluminum he milled two halves of a sphere. They can be sufficiently heated if held under running water, and a some leftover printer rails keep the two parts aligned as the ice orb is formed. Now [Brendan] just needs to work on his method of creating a crystal-clear ice block as a starter and he’ll have achieved total win.
Continue reading “Milling ice molds for craft cocktails”
While many people have tried their hand at anodizing aluminum at home, there are plenty who would just as soon leave it up to the professionals due to the highly concentrated sulfuric acid required for the process. [Ken] started thinking about the process and wondered if there was a way to get comparable results using chemicals that are easier to obtain and dispose of.
Through some experimentation he found that sodium bisulfate (NaHSO4), which is a sodium salt of sulfuric acid, can easily be used in its place with great results. The chemical is typically advertised in hardware and pool stores as “Aqua Chem”, and can be had at a very reasonable price. When paired with the proper DC current along with a cathode, the sodium bisulfate easily anodizes an aluminum workpiece and renders it ready for coloring with RIT, readily available cloth dye.
We were impressed with the results, and when looking at [Ken’s] test pieces, it seems that the metal dyed with sodium bisulfate has a more uniform, less streaky coloring to it. It’s also worth mentioning that [Ken] has found it is fairly easy to etch the aluminum before anodizing using a solution of sodium hydroxide, which is great for individuals who prefer a more matte finish.
If this is something that interests you, be sure to swing by his site. He has a posted nice video overview of the process that may be of some help.
Pop a few aluminum bits into this little RC racer and you’ll have power for around forty minutes. This concept, which has been patented, is the result of a college research project. It uses a chemical reaction between aqueous Sodium Hydroxide and aluminum. The result of that reaction is hydrogen, which is gathered and directed to a fuel cell that drives the car.
Novel? Yes. Interesting? Absolutely. But you should be raising an eyebrow at the dubious choice of fuel that is aluminum.
If you don’t know what we’re talking about let us paint you a picture. Aluminum is a metal that is refined from bauxite ore. It takes an immense amount of electricity to smelt the metal. This is usually justified because aluminum is one of the most recyclable substances on earth, capable of being melted down and reformed countless times. But dissolving it in drain cleaner breaks it down and then it’s gone. So what we have here simply must be the least efficient disposable battery so far developed. It’d probably use less resources to grow and harvest lemons as a power source.
Continue reading “Powering vehicles with aluminum”
This shiny little box was made from a soda can. You don’t need much to pull this off; an aluminum can, sand paper, scissors, a ballpoint pen, a straight edge, and some time. The embossing is done with the tip of the pen, but there’s a bit of a trick to it. The designs are first pressed into the metal from the underside of the aluminum. It is then flipped over and the outlines are traced, with one last tracing of the shape from the underside once that is completed. We think you’ll agree that this results in an impressive relief of the design.
This would make a nice project for that wedding ring you’ve been carrying around sans-case. Or perhaps this is just what you needed as an enclosure for your next project. You’ll find an instructional video after the break.
Continue reading “Making boxes from soda cans”
A failed chemistry experiment led [Jeri Ellsworth] to discover a flexible substrate for electroluminescent displays. We’re familiar with EL displays on the back of a glass panel like you would find in an audio receiver, but after making a mesh from aluminum foil [Jeri] looked at using the porous metal to host phosphors. She starts by cleaning foil and using a vinyl sticker to resist etching portions of the aluminum. It then goes into a bath of boric acid, electrified with the foil as the anode. As the foil etches she tests the progress by shining a laser through the foil. After this the phosphors are applied to the back surface of the foil, covered in a dielectric, and topped off with a conductive ink that will carry the AC necessary to excite the phosphors. This is layering materials in reverse compared to her EL PCB experiments. See [Jeri] explain this herself in the clip after the break.
You can see above that this produces a pretty well-defined display area. It reminds us of that color changing paint display. We think it would be worth a try to build a few 7-segment displays using this method.
Continue reading “Jeri makes flexible EL displays”
No, the picture above is not a store made steadicam. Rather, a CNC machined one by [Matt]. Interestingly, unlike most steadicams we’ve seen before the gimbal is not the main focus of the design though an aluminum machined gimbal would make us drool. The central idea is allowing for X and Y axis adjustment to get oddly weighted bulky camera’s exact center of gravity. [Matt’s] steadicam is also designed to handle more weight than commercial versions, and (if you already have a CNC) to be much cheaper. There’s no video, but from the skill of craftsmanship we can safely assume it’s as good and level as some of the best.
This bulky package is a Nixie tube wristwatch. We still like [Woz’s] watch better but this one has a few nice tricks of its own. Notably, there aren’t any buttons to set the time. Instead, a large magnet is used to actuate a magnetic switch inside the body. Speaking of enclosures, the case is aluminum and the face plate is polycarbonate but looks like it’s been vacuum formed. Check out the clip after the break.
Continue reading “Use a big magnet to set the time”