# Machining Copper From Algaecide

We love it when we find someone on the Internet who has the exact same problem we do and then solves it. [Hyperspace Pirate] starts a recent video by saying, “Oh no! I need to get rid of the algae in my pond, but I bought too much algaecide. If only there were a way to turn all this excess into CNC machined parts.” OK, we’ll admit that we don’t actually have this problem, but maybe you do?

Algaecide is typically made with copper sulfate. There are several ways to extract the copper, and while it is a little more expensive than buying copper, it is cost-competitive. Electrolysis works, but it takes a lot of power and time. Instead, he puts a more reactive metal in the liquid to generate a different sulfate, and the copper should precipitate out.

# Categorizing Steel

In the movie Conan the Barbarian, we hear a great deal about “the riddle of steel.” We are never told exactly what that riddle is, but in modern times, it might be: What’s the difference between 4150 and 1020 steel? If you’ve been around a machine shop, you’ve probably heard the AISI/SAE numbers, but if you didn’t know what they mean, [Jason Lonon] can help. The video below covers what the grade numbers mean in detail.

The four digits are actually two separate two-digit numbers. Sometimes, there will be five digits, in which case it is a two-digit number followed by a three-digit number. The first two digits tell you the actual type of steel. For example, 10 is ordinary steel, while 41 is chromium molybdenum steel. The last two or three digits indicate how much carbon is in the steel. If that number is, say, 40, then the steel contains approximately 0.40% carbon.

# A Two-Stroke Engine Made From Scratch Using Basic Hardware Store Parts

How hard could it to be to build a two-stroke internal combustion engine (ICE) from scratch? This is a challenge that [Camden Bowen] gladly set for himself, while foregoing such obvious wastes of time like first doing an in-depth literature study on the topic. That said, he did do some research and made the design in OnShape CAD before making his way over to the hardware store to make some purchases.

As it turns out, you can indeed build a two-stroke engine from scratch, using little more than some metal piping and other parts from the hardware store. You also need a welder and a lathe, with [Camden] using a Vevor mini-lathe that totally puts the ‘precision’ in ‘chatter’. As building an ICE requires a number of relatively basic parts that have to move with very little friction and with tight tolerances, this posed some challenges, but nothing that some DIY spirit can’t fix.

In the case of the very flexible boring bar on the lathe, improvising with some sturdy metal stock welded to a short boring bar resolved that, and precision was achieved. Together with an angle grinder, [Camden] was then able to manufacture the crank case, the cylinder and crank shaft and all the other pieces that make up an ICE. For the carburetor he used a unit off Amazon, which turned out to have the wrong throat size at 19 mm, but a 13 mm version worked. Ultimately, the first ICE constructed this way got destroyed mostly by running it dry and having the starter fluid acting as a solvent, but a full rebuild fixed all the issues.

This second attempt actually ran just fine the first time around, with oil in the crank case so that the poor engine wasn’t running dry any more. With a 40:1 fuel/oil mixture the little engine idles and runs as well as a two-stroke can, belching blue smoke and making a ruckus. This answers the question of whether you can build a two-stroke ICE with basic machining skills and tools, but of course the question that’s now on everyone’s lips is whether a four-stroke one would be nearly as ‘easy’. We wait with bated breath.

# Retrotechtacular: The Tools And Dies That Made Mass Production Possible

Here at Hackaday we’re suckers for vintage promotional movies, and we’ve brought you quite a few over the years. Their boundless optimism and confidence in whatever product they are advancing is infectious, even though from time to time with hindsight we know that to have been misplaced.

For once though the subject of today’s film isn’t something problematic, instead it’s a thing we still rely on today. Precision manufacturing of almost anything still relies on precision tooling, and the National Tool and Die Manufacturers Association is on hand in the video from 1953 below the break to remind us of the importance of their work.

The products on show all belie the era in which the film was made: a metal desk fan, CRT parts for TVs, car body parts, a flight of what we tentatively identify as Lockheed P-80 Shooting Stars, and a Patton tank. Perhaps for the Hackaday reader the interest increases though when we see the training of an apprentice toolmaker, a young man who is being trained to the highest standards in the use of machine tools. It’s a complaint we’ve heard from some of our industry contacts that it’s rare now to find skills at this level, but we’d be interested to hear views in the comments on the veracity of that claim, or whether in a world of CAD and CNC such a level of skill is still necessary. Either way we’re sure that the insistence on metrology would be just as familiar in a modern machine shop.

A quick web search finds that the National Tool and Die Manufacturers Association no longer exists, instead the search engine recommends the National Tooling And Machining Association. We’re not sure whether this is a successor organisation or a different one, but it definitely represents the same constituency. When the film was made, America was at the peak of its post-war boom, and the apprentice would no doubt have gone on to a successful and pretty lucrative career. We hope his present-day equivalent is as valued.

If you’re of a mind for more industrial process, can we direct you at die casting?

# Betta Aims To Bring Wire EDM To The Desktop

Just as practical nuclear fusion has been “only 20 years away” for the last 80 years or so, the promise of electrical discharge machining (EDM) in the home shop seems to always be just around the corner. It’s hard to understand why this is so — EDM is electrically and mechanically more complicated than traditional subtractive manufacturing techniques, so a plug-and-play EDM setup seems always just out of reach.

Or perhaps not, if this 3D printed 4-axis wire EDM machine catches on. It comes to us from [John] at Rack Robotics and is built around the Powercore EDM power supply that we’ve previously featured. Since wire EDM is a process that requires the workpiece to be completely immersed in a dielectric solution, the machine, dubbed “Betta,” is designed to fit inside a 10-gallon aquarium — get it?

A lot of thought went into keeping costs down. for example, rather than use expensive sealed motors, [John] engineered the double CoreXY platform to keep the motors out of the water bath using long drive shafts and sealed bearings. The wire handling mechanism is also quite simple, at least compared to commercial WEDM machines, and uses standard brass EDM wire. The video below shows the machine going to town of everything from aluminum to steel, with fantastic results on thin or thick stock.

While Rack Robotics is going to be offering complete kits, they’re also planning on open-sourcing all the build files. We’re eager to see where this leads, and if people will latch onto EDM with the same gusto they did with 3D printing.

# DIY Bimetallic Strip Dings For Teatime

Do you like your cup of tea to be cooled down to exactly 54 C, have a love for machining, and possess more than a little bit of a mad inventor bent? If so, then you have a lot in common with [Chronova Engineering]. In this video, we see him making a fully mechanical chime-ringing tea-temperature indicator – something we’d be tempted to do in silicon, but that’s admittedly pedestrian in comparison.

The (long) video starts off with making a DIY bimetallic strip out of titanium and brass, which it pretty fun. After some math, it is tested in a cup of hot water to ballpark the deflection. Fast-forward through twenty minutes of machining, and you get to the reveal: a tippy cup that drops a bearing onto a bell when the deflection backs off enough to indicate that the set temperature has been reached. Rube Goldberg would have been proud.

OK, so this is bonkers enough. But would you believe a bimetallic strip can be used as a voltage regulator? How many other wacky uses for this niche tech do you know?

Thanks [Itay] for the tip!

# There’s Hope For That Cheap Lathe Yet!

There may be few cases where the maxim that “you get what you pay for” rings true, than a lathe. The less you spend on a lathe, the closer you get to a lathe-shaped object and the further from, well, a lathe. [Camden Bowen] has bought a cheap lathe, and he’s not content with a lathe-shaped object, so he takes us in the video below through a set of upgrades for it. In the process he makes a much nicer lathe for an entirely reasonable sum.

First up are the bearings, in this case a set of ball races which aren’t really appropriate for taking lateral force. After a lot of effort and a tiny bit of damage he manages to remove the old bearings and get the new ones in place, though their slightly different dimensions means he has to replace a spacer with a temporary 3D printed item which he’ll turn in metal later. We learn quite a bit about cheap lathe tools and tool alignment along the way, and he ends up buying a better tool post to solve some of its problems. We were always not very good at grinding HSS edges, too.

At the end of it all he has a much better lathe, upping cost from \$774 to \$1062 which is still pretty good for what he has. Worth a look, if you too have a lathe-shaped object.