Scientists at the Swiss Federal Laboratories for Materials Science and Technology (Empa) recently developed a new technique for growing watch springs to tiny specifications. As it turns out, the creation of watch springs is ripe with opportunity for new materials research.
The technique involves using photo-etching and electrochemical deposition into cold, aqueous solutions. Compared to drawing and winding Nivarox wires, this is a fairly unconventional method for manufacturing. For as long as watchmaking has been around, creating the balance springs has been one of the most difficult parts of the job. The wires must be drawn to a thickness in the hundredths of millimeters and wound and tempered to the exact hardness, ductility, and elasticity while compensating for environmental factors. Many substances change their properties during fabrication, so the Empa team decided to look to pure materials research as a way to find a means for fabricating balance springs that would remain stable.
They took silicon wafers (the same kind used for solar panels and computer chips), covered them in gold and a thin layer of light sensitive paint, and etched the shape of a spring into the wafer. The wafer was then dipped into a galvanic bath containing a salt solution from a metallic alloy — the spring acts as a cathode so that when an electric current passes through the bath, metal is deposited at the base of the spring. Once the spring is built up, it is dissolved from the mold and examined. After a bit of smoothing, the final spring is washed and sent to a lab for prototype production.
The electroplated springs are currently on display at the Laboratory for Mechanics of Materials and Nanostructures at the Empa campus in Thun, Switzerland. In the meantime, the first pilot tests are being wrapped up, and the team is beginning to work with Swiss watchmakers to see if their springs can hold up inside watch mechanisms.
[Thanks to Qes for the tip!]
If an object is conductive or has been given a conductive coating, it can be given a metal skin via electroplating. Electroplating is a simple process that is perfectly accessible to anyone in possession of vinegar, salt, a power supply, and some metal such as copper or nickel.
The process might be simple, but as with all such things there are a few gotchas. One of them is this: because electricity follows the path of least resistance, recessed areas of an object may not electroplate well (or at all) no matter how long the object is left immersed. To address this, [Brodie Fairhall] designed a 3D printed electroplating marker. The marker is essentially a more refined version of brush plating, and allows more precision and control than full immersion in an electrolyte bath.
[Brodie] created an excellent video that explains all one needs to start electroplating, and demonstrates using his marker to electroplate complex recessed shapes. Watch him coat a 3D-printed cat pendant in both copper and nickel in the video embedded below. It’s concise, well-edited, and chock full of useful tips.
Continue reading “Make An Electroplating Marker, Because Plating Complex Objects Is Hard”
Over in Italy, [Robotfactory] has a new setup called CopperFace that they claim allows you to essentially electroplate 3D printed objects with a metal coating using copper, nickel, silver, or gold.
We’ve talked about electroplating on plastic before, but that technique required mixing graphite and acetone. The CopperFace kit uses a conductive graphite spray and claims it deposits about 1 micron of plating on the object every two minutes.
We couldn’t help but wonder if the graphite spray is just the normal stuff used for lubricant. While the CopperFace’s electroplating tech seems pretty standard (copper sulfate and copper/phosphorus electrodes), we also wondered if some of the simpler copper acetate process we’ve covered before might be workable.
Continue reading “Metal 3D Printing With Your Printer”
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.
[A_Steingrube] has posted a guide to his favorite method of copper electroplating. Plating copper onto other metals is popular with the steampunk crowd, but it does have other uses. Copper plate is often used as a prep step for plating other metals, such as nickel and silver. It also (usually) increases the conductivity of the metal to be plated. [A_Steingrube] is using the copper acetate method of plating. What is somewhat novel about his method is that he chose to make his own electrolyte solution from household chemicals. The copper acetate is created by mixing distilled vinegar and household hydrogen peroxide in a 50/50 ratio. The mixture is heated and then a piece of copper scouring pad is placed in. The scouring pad is partially dissolved, providing copper ions, and turning the solution blue.
The next step is to clean the material to be plated. [A_Steingrube] uses Cameo Aluminum and Stainless cleaner for this, though we think any good degreaser will work. The actual electroplating process consists of connecting a piece of copper to the positive terminal of a 6 volt battery. Copper scouring pad is again used for its high surface area. The material to be plated is connected to the negative side of the battery. He warns to keep the solution and the material being plated in constant motion to avoid heavy “burn spots”, which can flake off after the plating process. The results speak for themselves. As with any bare copper material, the electroplated layer will quickly oxidize if not protected.
Here’s a PCB fabrication process that makes us envious. It’s pretty darn close to fab-house quality at home. [Cpirius] is using a CNC mill and through hole plating technique to produce his double-sided circuit boards.
The video embedded after the break shows one board from start to finish. It begins with the mill drilling holes through some double-sided copper clad stock. Once the millings have been cleaned off the holes are coated with a mixture of waterproof ink and carbon. This prepares them for plating by making the holes themselves conductive. The board is then run through an electroplating process based on this guide.
Possibly the most interesting part of the process starts 52 seconds into the clip. The mill uses a conductive probe to generate a height map of the entire board. This allows it to vary the routing depth for perfectly cut isolation traces. That final routing process is pictured above.
Continue reading “Through Hole Plating And Milling At Home”
Copper bus bars are commonly used instead of wire for carrying high currents. [Dane] needed some bus bars for a project, but he was worried about corrosion. His solution was tin electroplating the bus bars to lower the risk of corrosion while keeping the conductivity high.
The process requires only two chemicals: hydrochloric acid and tin. The electrolyte solution is made by dissolving tin into the acid. Then the bus bar is placed in a diluted solution and a 1 A current is run through it. The result is a fine coating of tin on the copper, which will not corrode in water.
[Dane] mentions that he’d like to try the process with silver solder in the future, since it is easier to find than tin. He also wants to find a way to measure the amount of tin deposited onto the bus bars. This process could be helpful for anyone who needs some corrosion resistant high current conductors.
Check out a video of the plating process after the break.
Continue reading “DIY Tin Plating For Bus Bars”