Sometimes we need the look, feel, and weight of a metal part in a project, but not the metal itself. Maybe you’re going for that retro look. Maybe you’re restoring an old radio and you have one brass piece but not another. It’s possible to get a very metal like part without all of the expense and heat required in casting or the long hours in the metal fabrication shop.
Before investing in the materials for cold casting, it’s best to have practical expectations. A cold cast part will not take a high polish very well, but for brushed and satin it can be nearly indistinguishable from a cast part. The cold cast part will have a metal weight to it, but it clinks like ceramic. It will feel cool and transfers heat fairly well, but I don’t have numbers for you. Parts made with brass, copper, and iron dust will patina accordingly. If you want them to hold a bright shine they will need to be treated with shellac or an equivalent coating afterward; luckily the thermoset resins are usually pretty inert so any coating used on metal for the same purpose will do.
It is best to think of the material as behaving more or less like a glass filled nylon such as the kind used for the casing of a power tool. It will be stiff. It will flex a relatively short distance before crazing and then cracking at the stress points. It will be significantly stronger than a 3D printed part, weaker than a pure resin part, and depending on the metal; weaker than the metal it is meant to imitate.
Continue reading “Learn Resin Casting Techniques: Cold Casting”
It’s no secret that fossil fuels are quickly becoming extinct. As technology charges ever forward, they are disappearing faster and faster. Many of our current dependencies on fossil fuels are associated with high-energy applications like transportation. Since it’s unlikely that global transportation will ever be in decline for any reason other than fuel shortage itself, it’s imperative that we find something that can replicate the high energy density of fossil fuels. Either that, or go back to the drawing board and change the entire scope of global transportation.
Energy, especially solar and wind, cannot be created all over the world. Traditionally, energy is created in situ and shipped to other places that need it. The proposed solutions for zero-carbon energy carriers—batteries and hydrogen—all have their weaknesses. Batteries are a fairly safe option, but their energy density is pretty poor. Hydrogen’s energy density is higher, but its flammability makes it dangerously volatile to store and transport.
Recently, a group of researchers at McGill University in Canada released a paper exploring the use of metal powders as our zero-carbon fuel of the future. Although metal powders could potentially be used as primary energy sources, the transitory solution they propose is to use them as secondary sources powered by wind and solar primaries.
Continue reading “Are Powdered Metal Fuels Just a Flash in the Pan?”
I consider myself a fairly sharp guy. I’ve made a living off of being a scientist for over 20 years now, and I have at least a passing knowledge of most scientific fields outside my area. But I feel like I should be able to do something other than babble incoherently when asked about magnets. They baffle me – there, I said it. So what do I do about it? Write a Hackaday post, naturally – chances are I’m not the only one with cryptomagnetonescience, even if I just made that term up. Maybe if we walk through the basics together, it’ll do us both some good understanding this fundamental and mysterious force of nature.
Continue reading “Back to Basics: What’s the deal with Magnets?”
Cordless soldering irons are, as a rule, terrible. A few months ago, you could pick up a cordless soldering iron from Radio Shack that was powered by AAA batteries. You can guess how well those worked. There are butane-fueled soldering irons out there that will heat up, but then you’re left without the requisite degree of temperature control.
[Xavier] didn’t want to compromise on a mobile soldering iron, so he made a desktop version portable. His mobile temperature controlled soldering iron uses the same electronics that are found in inexpensive Hakko clones, and is powered by a LiPo battery.
The soldering station controller comes directly from eBay, and a DC/DC boost converter accepts just about any DC power supply – including an XT60 connector for LiPo cells. A standard Hakko 907 iron plugs into the front, and a laser cut MDF enclosure makes everything look great. There were a few modifications to the soldering station controller that involved moving the buttons and temperature display, but this build really is as simple as wiring a few modules together.
With an off-the-shelf LiPo battery, the iron heats up fast, and it doesn’t have a long extension cord to trip over. With the right adapter, [Xavier] can use this soldering station directly from a car’s cigarette power port, a great feature that will be welcomed by anyone who has ever worked on the wiring in a car.
Continue reading “A DIY Mobile Soldering Iron”
Visit any renaissance fair across the United States this fall and you’ll undoubtedly find a blacksmith. He’ll be sweating away in a tent, pounding on a piece of glowing steel set against an anvil. While the practice of the single blacksmith endures today, high-production ‘works of days past required increasing amounts of muscle. The more tireless the muscle, the better. The manual efforts of the blacksmith were replaced by huge hammers, and the blacksmith needed only to turn the piece between impressions and maintain a healthy respect for the awesome crushing power of the machine.
Last week, blacksmith enthusiasts completed restoration work on the Häfla hammer in Finspang, Sweden. The 333 year old hydraulic hammer hadn’t been used since 1924, when operations ceased at the Häfla Hammerforge. The ‘works was built in 1682 and used the German method of forging, which had been introduced to Sweden in the 1500s. Steel production was revolutionized in the 1800s by the Bessemer process, which resulted in a much stronger product. Continue reading “Retrotechtacular: Häfla Hammerforge Healed”
If you’ve done any woodworking in the past, odds are likely that you’ll eventually end up fixturing your stock in the crushing grip of a vise or C-Clamp. The results are painful, leaving a lasting impression of the clamp jaws on your beautiful, otherwise-unmarred piece of stock. Often, you’ll need to design around this issue, fixture it gently, or cushion the grip with a softer intermediate material. [Chimponabike] had other thoughts, though, and developed a technique for successfully popping the dimples out, returning clamped wood to its perfectly unmarred form.
The Technique itself is dead simple and takes only a few minutes to perform. Simply apply a small amount of water, let it seep into the wood, and then bring a hot iron down onto the soaked wood to evaporate off the soaked water–instantly inflating the wood back into its original form!
It’s not the first time we’ve abused our tools and home appliances to do some clever things with wood, but it’s certainly worth adding to that “Tome of Techniques: Wood Edition” that you’ve been building in your browser’s bookmarks bar.
Thanks for the tip, [James]!
Here’s a rose-colored look into the steelworks at Workington, Cumbria in northern England. At the time of filming in 1974, this plant had been manufacturing steel nonstop for 102 years using the Bessemer process. [Sir Henry Bessemer]’s method for turning pig iron into steel was a great boon to industry because it made production faster and more cost-effective.
More importantly, [Bessemer]’s process resulted in steel that was ten times stronger than that made with the crucible-steel method. Basically, oxygen is blown through molten iron to burn out the impurities. The silicon and manganese burn first, adding more heat on top of what the oxygen brings. As the temperature rises to 1600°C, the converter gently rocks back and forth. From its mouth come showers of sparks and a flame that burns with an “eye-searing intensity”. Once the blow stage is complete, the steel is poured into ingot molds. The average ingot weighs four tons, although the largest mold holds six tons. The ingots are kept warm until they are made into rail.
The foreman explains that Workington Works would soon be switching over to a more modern process. As it was, Workington ran a pair of Bessemer converters on a 40-minute schedule, ensuring constant steel production from ore to rail. Between 1872 and 1974, these converters created an estimated 25 million metric tons of steel.
Continue reading “Retrotechtacular: The Bessemer Converter”