metal

61 Articles

Keep The Sparks Away With A Plasma Cutting Table

December 5, 2021 by 8 Comments

For one-off projects or prototypes it’s not uncommon for us to make do with whatever workspace we have on hand. Using a deck railing as an impromptu sawhorse, for example, is one that might be familiar to anyone who owns a circular saw, but [Daniel] has a slightly different situation. He had been setting up metal workpieces on random chunks of brick in order to use his plasma cutter, but just like the home handyman who gets tired of nicking their deck with a saw, he decided to come up with a more permanent solution and built a custom plasma cutting table.

Plasma cutting has a tendency to throw up a lot of sparks, so most commercial offerings for plasma cutting tables include a water bath to catch all of the debris from the cutting process. [Daniel] builds his table over a metal tub to hold some water for this purpose. The table itself is built out of aluminum and designed to be built without welding even though most people with plasma cutters probably have welders as well. The frame is designed to be exceptionally strong and includes curved slats which add to the strength of the table. The table is also designed to be portable, so the curved slats stay in place when the table is moved.

While this might seem like an average metal table at first glance, the table is actually being designed with a homemade CNC machine in mind which [Daniel] is working on. The CNC plasma cutter needs a sturdy, flat surface and can’t be set up on bricks in the driveway, so this table suits both [Daniel]’s immediate needs to not shower himself in sparks every time he cuts something and also his future CNC machine’s need for a sturdy, flat workspace. We look forward to seeing that build being completed but in the meantime take a look at this motorized plasma cutter which has the beginnings of a CNC machine if in one direction only.

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3D Printer Cuts Metal

October 22, 2021 by 19 Comments

Every now and then we’ll see a 3D printer that can print an entire house out of concrete or print an entire rocket out of metal. But usually, for our budget-friendly hobbyist needs, most of our 3D printers will be printing small plastic parts. If you have patience and a little bit of salt water, though, take a look at this 3D printer which has been modified to cut parts out of any type of metal, built by [Morlock] who has turned a printer into a 5-axis CNC machine.

Of course, this modification isn’t 3D printing metal. It convers a 3D printer’s CNC capabilities to turn it into a machining tool that uses electrochemical machining (ECM). This process removes metal from a work piece by passing an electrode over the metal in the presence of salt water to corrode the metal away rapidly. This is a remarkably precise way to cut metal without needing expensive or heavy machining tools which uses parts that can easily be 3D printed or are otherwise easy to obtain. By using the 3D printer axes and modifying the print bed to be saltwater-resistant, metal parts of up to 3 mm can be cut, regardless of the type of metal used. [Morlock] also added two extra axes to the cutting tool, allowing it to make cuts in the metal at odd angles.

Using a 3D printer to perform CNC machining like this is an excellent way to get the performance of a machine tool without needing to incur the expense of one. Of course, it takes some significant modification of a 3D printer but it doesn’t need the strength and ridigity that you would otherwise need for a standard CNC machine in order to get parts out of it with acceptable tolerances. If you’re interested in bootstraping one like that using more traditional means, though, we recently featured a CNC machine that can be made from common materials and put together for a minimum of cost.

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Chainsaw Cuts More Than Timber

May 29, 2021 by 13 Comments

We often take electricity for granted, to the point of walking into a room during a power outage and still habitually flipping the light switch. On the other hand, there are plenty of places where electricity isn’t a given, either due to poor infrastructure or an otherwise remote location. To get common electric power tools to work in areas like these requires some ingenuity like that seen in this build which converts a chainsaw to a gas-driven grinder that can be used for cutting steel or concrete. (Video, embedded below.)

All of the parts needed for the conversion were built in the machine shop of [Workshop from scratch]. A non-cutting chain was fitted to it first to drive the cutting wheel rather than cut directly, so a new bar had to be fabricated. After that, the build shows the methods for attaching bearings and securing the entire assembly back to the gas-powered motor. Of course there is also a custom shield for the grinding wheel and also a protective housing for the chain to somewhat limit the danger of operating a device like this.

Even though some consideration was paid to safety in this build, we would like to reiterate that all the required safety gear should be worn. That being said, it’s not the first time we’ve seen a chainsaw modified to be more useful than its default timber-cutting configuration, like this build which turns a chainsaw into a metal cutting chop saw.

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Retrotechtacular: The Drama Of Metal Forming

May 29, 2021 by 22 Comments

It may seem overwrought, but The Drama of Metal Forming actually is pretty dramatic.

This film is another classic of mid-century corporate communications that was typically shown in schools, which the sponsor — in this case Shell Oil — seeks to make a point about the inevitable march of progress, and succeeds mainly in showing children and young adults what lay in store for them as they entered a working world that needed strong backs more than anything.

Despite the narrator’s accent, the factories shown appear to be in England, and the work performed therein is a brutal yet beautiful ballet of carefully coordinated moves. The sheer power of the slabbing mills at the start of the film is staggering, especially when we’re told that the ingots the mill is slinging about effortlessly weigh in at 14 tons apiece. Seeing metal from the same ingots shooting through the last section of a roller mill at high speed before being rolled into coils gives one pause, too; the catastrophe that would result if that razor-sharp and red-hot metal somehow escaped the mill doesn’t bear imagining. Similarly, the wire drawing process that’s shown later even sounds dangerous, with the sound increasing in pitch to a malignant whine as the die diameter steps down and the velocity of the wire increases.

There are the usual charming anachronisms, such as the complete lack of safety gear and the wanton disregard for any of a hundred things that could instantly kill you. One thing that impressed us was the lack of hearing protection, which no doubt led to widespread hearing damage. Those were simpler times, though, and the march of progress couldn’t stop for safety gear. Continue reading “Retrotechtacular: The Drama Of Metal Forming” →

Keep Coffee Warm Through Induction Heating

April 11, 2021 by 13 Comments

Transformers have an obvious use for increasing or decreasing the voltage in AC systems, but they have many other esoteric uses as well. Electric motors and generators are functionally similar and can be modeled as if they are transformers, but the truly interesting applications are outside these industrial settings. Wireless charging is essentially an air-core transformer that allows power to flow through otherwise empty space, and induction cooking uses a similar principle to induce current flow in pots and pans. And, in this case, coffee mugs.

[Sajjad]’s project is an effort to keep his coffee warm while it sits on his desk. To build this special transformer he places his mug inside a coil of thick wire which is connected to a square wave generator. A capacitor sits in parallel with the coil of wire which allows the device to achieve resonance at a specific tuned frequency. Once at that frequency, the coil of wire efficiently generates eddy currents in the metal part of the coffee mug and heats the coffee with a minimum of input energy.

While this project doesn’t work for ceramic mugs, [Sajjad] does demonstrate it with a metal spoon in the mug. While it doesn’t heat up to levels high enough to melt solder, it works to keep coffee warm in a pinch if a metal mug isn’t available. He also plans to upgrade it so it takes up slightly less space on his desk. For now, though, it can easily keep his mug of coffee hot while it sits on his test bench.

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Electroplating 3D Printed Parts For Great Strength

March 1, 2021 by 33 Comments

Resin 3D printers have a significant advantage over filament printers in that they are able to print smaller parts with more fine detail. The main downside is that the resin parts aren’t typically as strong or durable as their filament counterparts. For this reason they’re often used more for small models than for working parts, but [Breaking Taps] wanted to try and improve on the strength of these builds buy adding metal to them through electroplating.

Both copper and nickel coatings are used for these test setups, each with different effects to the resin prints. The nickel adds a dramatic amount of stiffness and the copper seems to increase the amount of strain that the resin part can tolerate — although [Breaking Taps] discusses some issues with this result.

While the results of electroplating resin are encouraging, he notes that it is a cumbersome process. It’s a multi-step ordeal to paint the resin with a special paint which helps the metal to adhere, and then electroplate it. It’s also difficult to ensure an even coating of metal on more complex prints than on the simpler samples he uses in this video.

After everything is said and done, however, if a working part needs to be smaller than a filament printer can produce or needs finer detail, this is a pretty handy way of adding more strength or stiffness to these parts. There’s still some investigating to be done, though, as electroplated filament prints are difficult to test with his setup, but it does show promise. Perhaps one day we’ll be able to print with this amount of precision using metal directly rather than coating plastic with it.

Thanks to [smellsofbikes] for the tip!

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How To Get Into Lost Wax Casting (with A Dash Of 3D Printing)

December 7, 2020 by 24 Comments

I’ve always thought that there are three things you can do with metal: cut it, bend it, and join it. Sure, I knew you could melt it, but that was always something that happened in big foundries- you design something and ship it off to be cast in some large angular building churning out smoke. After all, melting most metals is hard. Silver melts at 1,763 °F. Copper at 1,983 °F. Not only do you need to create an environment that can hit those temperatures, but you need to build it from materials that can withstand them.

Turns out, melting metal is not so bad. Surprisingly, I’ve found that the hardest part of the process for an engineer like myself at least, is creating the pattern to be replicated in metal. That part is pure art, but thankfully I learned that we can use technology to cheat a bit.

When I decided to take up casting earlier this year, I knew pretty much nothing about it. Before we dive into the details here, let’s go through a quick rundown to save you the first day I spent researching the process. At it’s core, here are the steps involved in lost wax, or investment, casting:

  1. Make a pattern: a wax or plastic replica of the part you’d like to create in metal
  2. Make a mold: pour plaster around the pattern, then burn out the wax to leave a hollow cavity
  3. Pour the metal: melt some metal and pour it into the cavity

I had been kicking around the idea of trying this since last fall, but didn’t really know where to begin. There seemed to be a lot of equipment involved, and I’m no sculptor, so I knew that making patterns would be a challenge. I had heard that you could 3D-print wax patterns instead of carving them by hand, but the best machine for the job is an SLA printer which is prohibitively expensive, or so I thought. Continue reading “How To Get Into Lost Wax Casting (with A Dash Of 3D Printing)” →