[Cody Reeder] had a problem. He wanted to make a ring for his girlfriend [Canyon], but didn’t have enough gold. [Cody and Canyon] spent some time panning for the shiny stuff last summer. Their haul was only about 1/3 gram though. Way too small to make any kind of jewelry. What to do? If you’re [Cody], you head up to your silver mine, and pick up some ore. [Cody] has several mines on his ranch in Utah. While he didn’t go down into the 75 foot deep pit this time, he did pick up some ore his family had brought out a few years back. Getting from ore to silver is a long process though.
First, [Cody] crushed the rock down to marble size using his homemade rock crusher. Then he roasted the rock in a tire rim furnace. The ore was so rich in lead and silver that the some of the metal just dropped right out, forming splatters on the ground beneath the furnace. [Cody] then ball milled the remaining rock to a fine powder and panned out the rest of the lead. At this point the lead and silver were mixed together. [Cody] employed Parks process to extract the silver. Zinc was added to the molten lead mixture. The silver is attracted to the zinc, which is insoluble in lead. The result is a layer of zinc and silver floating above the molten lead. Extracting pure silver is just a matter of removing the zinc, which [Cody] did with a bit of acid.
Cody decided to make a silver ring for [Canyon] with their gold as the stone. He used the lost wax method to create his ring. This involves making the ring from wax, then casting that wax in a mold. The mold is then heated, which burns out the wax. The result is an empty mold, ready for molten metal.
The cast ring took a lot of cleanup before it was perfect, but the results definitely look like they were worth all the work.
Continue reading “[Cody] Takes us From Rock To Ring”
Usually when Hackaday covers electroplating techniques, it’s to talk about through-hole PCB plating. But did you know you can use the same method to produce beautiful copper and silver crystal structures?
[Fred and Connie Libby] are kind enough to share how they make their crystals that they sell in tiny glass vials you can wear around your neck. The process is simple as you would think; it’s just an electrolyte solution, with a current passing through it, depositing the metal in an ion-exchange. Rather then stop once the part is sufficiently covered, you let the process run amok, and soon large crystal formations begin to emerge. [Fred and Connie] share their technique very briefly, so if you’re looking for a more detailed how-to guide, you can find one here.
Although silver crystals are a bit out of our budget, we wonder how large of a copper crystal could be grown? Large enough to be displayed on a coffee table? Surely such a work of art and science could be an interesting conservation piece in any hacker’s home.
There are two printers being shown off at the 2015 Consumer Electronics shows which really spark our interest. They are the Voltera and the Voxel8. Each is taking on the challenge of printing circuits. They use similar techniques but approach the problem in very different ways.
[Michael Bell] poses with the Voxel8
Quad on the print bed of the Voxel8
3D printed quadcopter — conductive traces and all
The Voxel8 marries the idea of a 3D printer with a silver conductive ink dispenser. You start by modeling your entire design, hardware and electronics, all in one. The printer will then begin the 3D print, pausing when necessary for you to add electronics and mechanicals. With the parts — and their pins — in place it lays out the conductive ink to connect the components and then continues with the 3D printing to finish the object.
[Alroy Almeida] poses with the Voltera
PCB demo, colored traces are for insulation between layers
PCB with components populated
The Voltera is a PCB printer that uses silver conductive ink. It prints the ink onto a substrate. Pads made of the ink are used to solder the components in place after the printing is finished. The trick added to this design is the ability to print two layers, both on the same side of the board. There is a second ink material which is an insulator. It is laid over the first conductive layer before the second is printed, allowing traces to cross over each other.
Congratulations to the Voltera team who won $50k from the 2015 Hardware Battlefield at CES.
We didn’t see enough to shake our skepticism about the viability of silver conductive ink to take the place of copper on prototype boards. But if anyone is going to make the case that it is plausible these two offerings will.
One interesting thing about the Voxel8 is the ability to specify point-to-point wiring as a “part”. If you do so, the machine will pause while you solder the wires in place before it encapsulates them with the rest of the print. Of course if you’re going to do this manually it shouldn’t really matter which printer you use for it.
What do think about the future of conductive ink for prototyping? Lets us know in the comments.
If you’re hoarding old electronics like us, there’s a good probability you have a decent amount of gold sitting around in cardboard boxes and storage containers. Everything from old PCI cards, IC pins, and even printers have a non-negligible amount of precious metals in them, but how do you actually process those parts and recover that gold? [Josehf] has a great tutorial for gold recovery up on Instructables for the process that netted him an ounce of gold for three months’ work.
After cutting up a few circuit boards to remove the precious gold-bearing parts, [Josehf] threw these parts into a mixture of muriatic acid and hydrogen peroxide. After a week, the acid darkened and the gold slowly flaked off into dust. This gold dust was separated from the acid by passing it through a coffee filter and readied for melting into a single nugget.
Gold melts at 1064 ˚C, much hotter than what can be obtained by a simple propane torch. This melting point can be reduced by the addition of borax, allowing the simplest tools – a propane torch and a terra cotta crucible – to produce a small gold nugget.
For three months of collecting, stripping, and dissolving electronic parts, [Josehf] netted 576.5 grains of gold, or at current prices, about $1500 worth of the best conductor available. Not too bad, but not something we’d use as a retirement plan.
Thanks [Matthias] for sending this in.