The Mystery Of Automatic Lubricators Is Revealed

June 30, 2022 by Lewin Day 14 Comments

Industrial machines have all kinds of moving parts that require regular lubrication in order to prevent wear and damage. Historically, these would require regular visits from maintenance personnel to keep them greased up and slippery. Automatic lubricators eliminate that job by regularly dosing machines with fresh grease, and [Big Clive] decided to see what makes them tick.

The device can be set to deliver a full load of grease over a period of 1-12 months.

The simplest models merely use a spring to slowly force grease out over time. Changing the spring changes the rate at which grease is dispensed. Chemical versions exist too. A chemical pill is selected and inserted into a chamber with liquid, which releases gas over time. As gas is released, it creates pressure which forces a plunger down, dispensing grease over time.

Perhaps the fanciest versions are the electronic models, however, which have a dial on the back for selecting the rate of grease delivery. Turning the dial changes a resistance that is connected across two zinc-air cells which are sealed. Apparently, when current is forced through these cells and they’re excluded from oxygen, the cells liberate hydrogen gas, according to a patent [Big Clive] found. This then forces down the plunger, dispensing the grease. Turning the dial changes the resistance, changing the rate at which grease is dispensed.

The quest for labor saving in industry has produced multiple designs of automated lubricator, all of which are fantastically simple and optimised for purpose. It shows just how much can be achieved with a few components and some creative thinking, where one’s first impulse might be to reach for a timer or microcontroller to do the job.

Lubrication is incredibly important – don’t forget it when building your CNC machines! Video after the break.

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ESP32 Camera Slider Build Keeps Things In Perspective

June 30, 2022 by Tom Nardi 2 Comments

We’ve seen a lot of camera slider builds here at Hackaday, and for good reason: having one really lets you take your project documentation, especially videos, to the next level. It’s one of those force multiplier builds — after you’ve completed it, it can help you make all your future projects just that much better. But we’re also no strangers to seeing these projects become overly complex, which can often make it difficult for others to replicate.

But that’s not the case here. The motorized camera slider that [Sasa Karanovic] recently sent our way does exactly what you’d expect, and little else. That’s not meant as a dig — sometimes the best approach is to keep it simple. Unless you’re a professional photographer or videographer, it’s unlikely you need a complicated motion rig. This design is perfect for the hacker or maker who wants to spruce up their project videos, but doesn’t want to spend months fiddling with the design. Continue reading “ESP32 Camera Slider Build Keeps Things In Perspective” →

A Home Made Laser Cutter For $700

June 29, 2022 by Matthew Carlson 36 Comments

While some decent lasers are out there for under $400 USD, they tend to be a little small. What if you wanted something a little nicer but didn’t want to jump to the $2,000 category? The answer for [Owen Schafer] was to build it with parts he had lying around and a few strategic purchases.

While he was initially planning on using a diode laser, doing anything more than engraving is tricky. He purchased a cheap 40 W CO2 laser tube, but it meant that he needed water cooling, mirrors, and more complex stuff that a diode doesn’t need. The frame is aluminum extrusion held together with 3D printed plates. Given there was a powerful laser bouncing around with mirrors, a plywood box formed the enclosure.

The stepper controller is an Arduino Mega running the Marlaser firmware, though [Owen] admits perhaps a laser cutter-specific driver board would have been better as he spent many hours trying to get the Arduino to do what he wanted. Air ventilation is a tube with a fan that vents out a nearby window. Water cooling is just a bucket of water with a pump in it. A simple nylon hose connected to a compressor with a maximum airflow valve provides an air assist while cutting. Finally, we’re happy to report that [Owen] bought safety glasses specific to his laser to protect his eyes and researched how to ground the high voltages generated.

We particularly loved seeing all of [Owen’s] test cuts. He proudly displayed his boxes, sharks, and lamp shades like anyone with their new laser cutter is wont to do. If you’re looking to upgrade your laser, there’s an add-on for detecting materials optically or a relatively cheap laser bed you can throw in your laser.

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Metal Detector Gets Help From Smartphone

June 27, 2022 by Bryan Cockfield 15 Comments

[mircemk] is quite a wizard when it comes to using coils of wires in projects, especially when their application is within easy-to-build metal detectors. There are all kinds of ways to send signals through coiled wire to detect metal objects in the ground, and today [mircemk] is demonstrating a new method he is experimenting with which uses a smartphone to detect the frequency changes generated by the metal detector.

Like other metal detectors, this one uses two coils of wire with an oscillator circuit and some transistors. The unique part of this build, though, is how the detector alerts the user to a piece of metal. Normally there would be an audible alert as the frequencies of the circuit change when in the presence of metal, but this one uses a smartphone to analyze the frequency information instead. The circuit is fed directly into the headphone jack on the smartphone and can be calibrated and used from within an Android app.

Not only can this build detect metal, but it can discriminate between different types of metal. [mircemk] notes that since this was just for experimentation, it needs to be calibrated often and isn’t as sensitive as others he’s built in the past. Of course this build also presumes that your phone still has a headphone jack, but we won’t dig up that can of worms for this feature. Instead, we’ll point out that [mircemk] has shown off other builds that don’t require any external hardware to uncover buried treasure.

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Injection Molds: Aluminum Or Resin?

June 27, 2022 by Al Williams 11 Comments

[JohnSL] and his friend both have injection molding machines. They decided to compare the aluminum molds they usually use with some 3D printed molds created with a resin printer. They used two different resins, one on each side of the mold. You can see a video of the results below.

One half of the mold used ordinary resin while the other side used a resin that is made to hold up to higher temperatures. As you might expect, the lower-temperature resin didn’t stand up well to molten plastic. However, the higher temperature resin did somewhat better. It makes sense, though, that an aluminum mold draws more heat out of the plastic which is helpful in the molding process.

The higher temperature — and more expensive — resin did seem to hold up rather well, though. Of course, this was just to test. In real life, you’d want to use the better resin throughout.

No surprise, the resin molds didn’t last nearly as long as a proper mold. After 70 shots, the mold was worn beyond what you’d want to use. So not necessarily something you’d want to use for a real production run, but it should be enough for a quick prototype before you go to the expense of creating a proper mold.

We wonder if there are some other tricks to get better results. A comment from [TheCrafsMan] suggests that clear resin UV cures better, and that might produce better results. In fact, there are a lot of interesting comments on the video from people who have varied experiences trying to do the same thing.

If nothing else, watching the mill cut through the aluminum around the 15-minute mark is always interesting to watch. If you don’t already have an injection molding setup, you can always build one. We’ve seen more than one design.

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Getting Serial Data Out Of An Old Spectrophotometer

June 25, 2022 by Lewin Day 15 Comments

[Jure Spiler] came into possession of an old spectrophotometer, which measures the absorbance and transmittance of light in a sample. Getting data out of the device was difficult, particularly as the model in question was an educational version missing some functionality. However, perseverance got the old machine talking happily to a PC.

After an earlier experiment with sniffing the signals being sent to the LCD, [Jure] did some more research. It turned out that a special expensive cable could hook up to the device’s parallel port and deliver serial data, for the low price of € 356 Euros. Now knowing a serial output was present, [Jure] was able to find the data stream desired.

Hooking up a logic analyzer to the “parallel port” on the machine revealed that the device would actually send serial data out over certain pins on the port. The trick that made it harder was that it was in Inverted RS232 form. Thus, all it took was a simple TTL inverter hooked up to a USB-TTL adapter to get the device talking to a modern PC.

With that achieved, [Jure] was able to whip up a simple VB6 program to collect data from the spectrometer and put it in a CSV file for further analysis. There’s even a program to graph the data right off the bat, making the scientific instrument easier and quicker to use than ever!

Oftentimes, old scientific hardware like this isn’t especially difficult to hack. It’s usually just hard enough to make busy scientists stump up the cash for the fancy adapters and cable, while being no match for the dedicated hacker!

A Water Leak Detector That Listens Carefully

June 24, 2022 by Lewin Day 14 Comments

Water leaks can be pernicious things. Even just a few drips per minute happening undetected inside a wall can cause major damage if left unrepaired for long enough. AquaPing is a new device that hopes to detect difficult-to-find water leaks with the aid of acoustic methods.

The AquaPing is a so-called “stand-off” sensor that is intended to detect leaks at a distance, even if they are inside a wall. No contact is needed with the plumbing itself. Instead, the device detects the broadband high-frequency noise created when water leaks from a pipe under pressure.

It’s a method that’s best suited to leaks from cracks or loose fittings. These generate a characteristic hiss that can be picked up with signal analysis even if the noise itself is obscured to human perception by other noises in the area. However, leaks like a hole in a gutter or a dripping rusted-out water tank are best found by other methods, as they don’t create this same signature noise.

The device will soon be launched on CrowdSupply as a purchasable product, however the project is fully open source for those eager to dive in themselves. We’ve featured some other really creative leak detectors before, too! Video after the break.

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