A Cheap DIY PLC Based On The Atmega328P

If you’re running a big factory, you’ve probably got a massively expensive contract with a major programmable logic controller (PLC) manufacturer. One shudders to think about the cost of the service subscription on that one. If you’re working on a smaller scale, though, you might consider a DIY PLC like this one from [Mr Innovative.]

PLCs are rarely cutting-edge; instead, they’re about reliability and compliance with common industry standards. To that end, this design features the ATmega328P. Few other microcontrollers are as well understood or trusted as that one. The device is compatible with RS232 and RS485 and will run off 24 VDC, both of which you would find in a typical industrial environment. It offers 24 V digital inputs and outputs, as well as analog inputs and outputs from 0 to 10 V. [Mr Innovative] demonstrates it by hooking up a DWIN human-machine interface (HMI) for, well… human interaction, and a variable frequency drive to run a motor.

If you want to run a basic industrial-lite system but can’t afford the real industrial price tag, you might enjoy tinkering around at this level first. It could be a great way to get a simple project up and running without breaking the bank. Video after the break.

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The Mystery Of Automatic Lubricators Is Revealed

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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Water And Molten Aluminium Is A Dangerous Combination

It is not uncommon for a Hackaday writer to trawl the comments section of a given article, looking for insights or to learn something new. Often, those with experience in various fields will share kernels of knowledge or raise questions on a particular topic. Recently, I happened to be glazing over an article on aluminium casting with interest, given my own experience in the field. One comment in particular caught my eye.

 And no, the water won’t cause a steam explosion. There’s a guy on youtube (myfordlover, I think) who disproves that myth with molten iron, pouring the iron into water, pouring water into a ladle of molten iron and so on. We’ll be happy to do a video demonstrating this with aluminum if so desired.

Having worked for some time in an aluminium die casting plant, I sincerely hope [John] did not attempt this feat. While there are a number of YouTube videos showing that this can be done without calamity, there are many showing the exact opposite. Mixing molten aluminium and water often ends very poorly, causing serious injury or even fatalities in the workplace. Let’s dive deeper to see why that is.

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MakerBot Moves Away From Makers With New Printer

If you’ve been following the desktop 3D printing market for the last couple years, you’re probably aware of the major players right now. Chinese companies like Creality are dominating the entry level market with machines that are priced low enough to border on impulse buys, Prusa Research is iterating on their i3 design and bringing many exciting new features to the mid-range price point, and Ultimaker remains a solid choice for a high-end workhorse if you’ve got the cash. But one name that is conspicuously absent from a “Who’s Who” of 3D printing manufacturers is MakerBot; despite effectively creating the desktop 3D printing market, today they’ve largely slipped into obscurity.

So when a banner popped up on Thingiverse (MakerBot’s 3D print repository) advertising the imminent announcement of a new printer, there was a general feeling of surprise in the community. It had been assumed for some time that MakerBot was being maintained as a zombie company after being bought by industrial 3D printer manufacturer Stratasys in 2013; essentially using the name as a cheap way to maintain a foothold in the consumer 3D printer market. The idea that they would actually release a new consumer 3D printer in a market that’s already saturated with well-known, agile companies seemed difficult to believe.

But now that MakerBot has officially taken the wraps off a printer model they call Method, it all makes sense. Put simply, this isn’t a printer for us. With Method, MakerBot has officially stepped away from the maker community from which it got its name. While it could be argued that their later model Replicator printers were already edging out of the consumer market based on price alone, the Method makes the transition clear not only from its eye watering $6,500 USD price tag, but with its feature set and design.

That said, it’s still an interesting piece of equipment worth taking a closer look at. It borrows concepts from a number of other companies and printers while introducing a few legitimately compelling features of its own. While the Method might not be on any Hackaday reader’s holiday wish list, we can’t help but be intrigued about the machine’s future.

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Surfboard Industry Wipes Out, Innovation Soon Follows

For decades, Gordon Clark and his company Clark Foam held an almost complete monopoly on the surfboard blank market. “Blanks” are pieces of foam with reinforcing wood strips (called “stringers”) in a rough surfboard shape that board manufacturers use to make a finished product, and Clark sold almost every single one of these board manufacturers their starting templates in the form of these blanks. Due to environmental costs, Clark suddenly shuttered his business in 2005 with virtually no warning. After a brief panic in the board shaping industry, and a temporary skyrocketing in price of the remaining blanks in existence, what followed next was rather surprising: a boom of innovation across the industry.

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Mod Your Camera With ModBus

Industrial hardware needs to be reliable, tough, and interoperable. For this reason, there are a series of standards used for command & control connections between equipment. One of the more widespread standards is ModBus, an open protocol using a master-slave architecture, usually delivered over RS-485 serial. It’s readily found being used with PLCs, HMIs, VFDs, and all manner of other industrial equipment that comes with a TLA (three letter acronym).

[Absolutelyautomation] decided to leverage ModBus to control garden variety digital cameras, of the type found cluttering up drawers now that smartphones have come so far. This involves getting old-school, by simply soldering wires to the buttons of the camera, and using an Arduino Nano to control the camera while talking to the ModBus network.

This system could prove handy for integrating a camera into an industrial production process to monitor for faults or defective parts. The article demonstrates simple control of the camera with off-the-shelf commercial PLC hardware. Generally, industrial cameras are very expensive, so this hack may be useful where there isn’t the budget for a proper solution. Will it stand up to industrial conditions for 10 years without missing a beat? No, but it could definitely save the day in the short term for a throwaway price. One shortfall is that the camera as installed will only save pictures to its local memory card. There’s a lot to be said for serving the images right to the engineer’s desk over a network.

We’ve seen [Absolutelyautomation]’s work before – check out this implementation of Pong on an industrial controller.

Protecting Your Home Against Potato Invaders

Not sure where the potatoes were sneaking in, [24Gospel] did what any decent hacker would do: strapped a camera to a Raspberry Pi, hacked a bit on OpenCV, and built himself a potato detection system. Now those pesky Russets can’t get into the house without tripping the tuber alarm.

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OK, seriously. [24Gospel] works for a potato farm as a systems/software developer. (How big does a potato farm have to be to require a dedicated software guy?) His system is still a first step, but the goal is to grade the potatoes, record data about size and defects, and even tell different potato types apart. And he’s found decent success so far, especially for the money. We don’t often build projects that need to operate in hostile environments, but we appreciate the nice plastic case and rugged adjustable steel frame that supports the Pi and camera over the sorting bed.

Even more, we applaud the hacker spirit here. [24Gospel] is obviously working in a serious production environment, but still he’s trying out new things in an attempt to make it work better. While it would be impossible to quantify the impact of this kind of on-the-job ingenuity, we bet it’s not insignificant. Why don’t we see more documented workplace hacks around here? Would the unsung heroes please stand up?

[via /r/raspberry_pi]