Energy drinks are a staple of those who want to get awake and energetic in a hurry. But what if said energy is not in enough of a hurry for your taste? After coming across a thrice concentrated energy drink, [Nile Blue] decided to make a 100 times concentrated Redbull.
Energy drinks largely consist of water with caffeine, flavoring and sugar dissolved inside. Because a solution can only be so strong, so instead of normal Redbull, a sugar free variant was used. All 100 cans were gathered into a bucket to dry the mixture, but first, it had to be de-carbonated. By attaching a water agitator to a drill, all the carbon dioxide diffused in the water fell out of solution. A little was lost, but the process worked extremely well.
The rotary evaporator (rotovap) rarely appears outside of well-provisioned chemistry labs. That means that despite being a fundamentally simple device, their cost generally puts them out of reach for amateur chemists. Nevertheless, they make it much more convenient to remove a solvent from a solution, so [Markus Bindhammer] designed and built his own.
Rotary evaporators have two flasks, one containing the solution to be evaporated, and one that collects the condensed solvent vapors. A rotary joint holds the evaporating flask partially immersed in a heated oil bath and connects the flask’s neck to a fixed vapor duct. Solvent vapors leave the first flask, travel through the duct, condense in a condenser, and collect in the second flask. A motor rotates the first flask, which spreads a thin layer of the solution across the flask walls, increasing the surface area and causing the liquid to evaporate more quickly.
Possibly the trickiest part of the apparatus is the rotary joint, which in [Markus]’s implementation is made of a ground-glass joint adapter surrounded by a 3D-printed gear adapter and two ball bearings. A Teflon stopper fits into one end of the adapter, the evaporation flask clips onto the other end, and a glass tube runs through the stopper. The ball bearings allow the adapter to rotate within a frame, the gear enables a motor to drive it, the Teflon stopper serves as a lubricated seal, and the non-rotating glass tube directs the solvent vapors into the condenser.
The flasks, condenser, and adapters were relatively inexpensive commercial glassware, and the frame that held them in place was primarily made of aluminium extrusion, with a few other pieces of miscellaneous hardware. In [Markus]’s test, the rotovap had no trouble evaporating isopropyl alcohol from one flask to the other.
Semiconductor fabrication is complicated requiring nasty chemicals for everything from dopants to etchants. Working with such chemicals at home is dangerous and after releasing hydrochloride acid fumes into his lab, [ProjectsInFlight] decided the time was right to get one for a mere $200.
I can hear the readers down in the comments already saying, “why not just make one?” But a properly engineered fume hood provides laminar flow which absolutely ensures no leakage of fumes out of the hood. However, such proper engineering comes with an impressive price tag, so the used market was the only choice. This is less dangerous then it sounds as companies are required by both OSHA and the EPA to clean their fume hoods before removal, so no chemical residue should remain after purchase.
[BPS.space] takes model rocketry seriously, and their rockets tend to get bigger and bigger. If there’s one thing that comes with the territory in DIY rocketry, it’s the constant need to solve new problems.
Coating the inside of a tube evenly with a thick, goopy layer before it cures isn’t easy.
One such problem is how to coat the inside of a rocket motor tube with a thermal liner, and their solution is a machine they made and called the Limb Remover 6000 on account of its ability to spin an 18 kg metal tube at up to 1,000 rpm which is certainly enough to, well, you know.
One problem is that the mixture for the thermal liner is extremely thick and goopy, and doesn’t pour very well. To get an even layer inside a tube requires spin-casting, which is a process of putting the goop inside, then spinning the tube at high speed to evenly distribute the goop before it cures. While conceptually straightforward, this particular spin-casting job has a few troublesome difficulties.
For one thing, the uncured thermal liner is so thick and flows so poorly that it can’t simply be poured in to let the spinning do all the work of spreading it out. It needs to be distributed as evenly as possible up front, and [BPS.space] achieves that with what is essentially a giant syringe that is moved the length of the tube while extruding the uncured liner while the clock is ticking. If that sounds like a cumbersome job, that’s because it is.
The first attempt ended up scrapped but helped identify a number of shortcomings. After making various improvements the second went much better and was successfully tested with a 12 second burn that left the tube not only un-melted, but cool enough to briefly touch after a few minutes. There are still improvements to be made, but overall it’s one less problem to solve.
Most research on electroplating tries to find ways to make it plate parts more uniformly. [Ajc150] took the opposite direction, though, with his selective electroplating project, which uses an electrode mounted on a CNC motion system to electrochemically print images onto a metal sheet (GitHub repository).
Normally, selective electroplating would use a mask, but masks don’t allow gradients to be deposited. However, electroplating tends to occur most heavily at the point closest to the anode, and the effect gets stronger the closer the anode is. To take advantage of this effect, [ajc150] replaced the router of an inexpensive 3018 CNC machine with a nickel anode, mounted an electrolyte bath in the workspace, and laid a flat steel cathode in it. When the anode moves close to a certain point on the steel cathode, most of the plating takes place there.
To actually print an image with this setup, [ajc150] wrote a Python program to convert an image into set of G-code instructions for the CNC. The darker a pixel of the image was, the longer the electrode would spend over the corresponding part of the metal sheet. Since darkness wasn’t linearly proportional to plating time, the program used a gamma correction function to adjust times, though this did require [ajc150] to recalibrate the setup after each change. The system works well enough to print recognizable images, but still has room for improvement. In particular, [ajc150] would like to extend this to a faster multi-nozzle system, and have the algorithm take into account spillover between the pixel being plated and its neighbors.
Although Charles Hall conducted his first successful run of the Hall-Héroult aluminium smelting process in the woodshed behind his house, it has ever since remained mostly out of reach of home chemists. It does involve electrolysis at temperatures above 1000 ℃, and can involve some frighteningly toxic chemicals, but as [Maurycy Z] demonstrates, an amateur can now perform it a bit more conveniently than Hall could.
[Maurycy] started by finding a natural source of aluminium, in this case aluminosilicate clay. He washed the clay and soaked it in warm hydrochloric acid for two days to extract the aluminium as a chloride. This also extracted quite a bit of iron, so [Maurycy] added sodium hydroxide to the solution until both aluminium and iron precipitated as hydroxides, added more sodium hydroxide until the aluminium hydroxide redissolved, filtered the solution to remove iron hydroxide, and finally added hydrochloric acid to the solution to precipitate aluminium hydroxide. He heated the aluminium hydroxide to about 800 ℃ to decompose it into the alumina, the starting material for electrolysis.
To turn this into aluminium metal, [Maurycy] used molten salt electrolysis. Alumina melts at a much higher temperature than [Maurycy]’s furnace could reach, so he used cryolite as a flux. He mixed this with his alumina and used an electric furnace to melt it in a graphite crucible. He used the crucible itself as the cathode, and a graphite rod as an anode. He does warn that this process can produce small amounts of hydrogen fluoride and fluorocarbons, so that “doing the electrolysis without ventilation is a great way to poison yourself in new and exciting ways.” The first run didn’t produce anything, but on a second attempt with a larger anode, 20 minutes of electrolysis produced 0.29 grams of aluminium metal.
[Maurycy]’s process follows the industrial Hall-Héroult process quite closely, though he does use a different procedure to purify his raw materials. If you aren’t interested in smelting aluminium, you can still cast it with a microwave oven.
Content warning: Human alteration and scalpels. General warning: We are not speaking as doctors. Or lawyers.
If you watch sci-fi, you probably do not have to think hard to conjure a scene in a trendy bar where the patrons have glowing make-up or tattoos. That bit of futuristic flair was possible years ago with UV-reactive tattoo ink, but it has the unfortunate tendency to permanently fade faster than traditional ink. [Miana], a biohacker, wanted something that could last forever and glow on its own. After months of research and testing, she presents a technique with a silica-coated powder and scarification. Reddit post with graphic content.
