Old Scanner Finds New Life In DIY PCB Fab

December 20, 2017 by Dan Maloney 33 Comments

Cheap, high-quality PCBs are truly a wonder of our age. That a professionally fabricated board with silkscreen and solder mask can be ordered online and delivered to your door has lowered the bar between a hobbyist project and a polished product. But the wait can be agonizing, and it can throw a wrench into the iterative design process. What to do?

[Andras Kabai] knows the answer to that, and this former flatbed scanner turned into a UV exposer is the centerpiece of his DIY board fab. The old Mustek scanner was a couple of bucks secondhand, and provided not only the perfect form-factor for a board scanner but a trove of valuable parts to reuse. [Andras] replaced the original fluorescent light bar with a long, narrow PCB stuffed with UV LEDs, and added an Arduino Mega to control the original stepper drive. The project looks like it went through a little feature creep, with an elaborate menu system and profiles that include controls for exposure time, the brightness of the LED array via PWM, and the length of board that gets exposed. It’s clearly a work in progress, but early results are encouraging and we’ll be watching to see how [Andras]’ in-house fab shapes up.

This approach to PCB fab is only one of many, of course. You can turn a budget 3D-printer into a PCB machine, or even use an LCD to mask the boards during exposure. The latter intrigues us — an LCD mask and a scanning UV light source could make for a powerful PCB creation tool.

The Miracle Of Injection Molding: How Does It Work?

December 17, 2017 by Bryan Cockfield 18 Comments

Pretty much any household item nowadays has an involved, extremely well-thought-out manufacturing method to it, whether it’s a sheet of paper, an electrical outlet, a can of tuna, or even the house itself. Some of the stories of how these objects came to be are compelling, though, as one of the recent videos from [This Old Tony] shows as he takes a deep dive into a $5 ball valve, and uses it to talk about all of the cool things you can do with injection molding.

Injection molding is the process of casting molten plastic into more useful pieces of plastic. In this case it’s a plumbing valve which might seem simple on the surface, but turns out to be much more involved. These ball valves are extremely reliable but have a very small price tag, meaning that a lot of engineering must have gone into their design. What is unearthed in the video is that injection molding allows parts to be cast into the molds of other parts, and the means by which those parts don’t all melt together, and how seals can be created within the part itself. All of this happens with a minimal number of parts and zero interaction from a human, or from any robot that isn’t the injection mold itself.

The video goes into exceptional detail on these valves specifically but also expounds on various techniques in injection molding. Similar to the recognition the seemingly modest aluminum can deserves, the injection molded ball valve deserves a similar amount of respect. While [This Old Tony] usually focuses on metalworking, he often tackles other interesting topics like this and this video is definitely worth checking out.

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Digital Kiln

December 16, 2017 by Brian McEvoy 31 Comments

A kiln or foundry is too often seen as a piece of equipment which is only available if a hackspace is lucky enough to have one or individuals are dedicated enough to drop the cash for one of their own. [The Thought Emporium] thought that way until he sourced materials to make his own kiln which can also be seen after the break. It costs half the price of a commercial model not including a failed—and exploded—paint can version.

As described in the video, these furnaces are tools capable of more than just pottery and soft metal baubles. Sure, a clay chess set would be cool but what about carbon fiber, graphene, aerogel, and glass? Some pretty hot science happens at high temperatures.

We get a nice walk-through of each part of the furnace starting with the container, an eleven-gallon metal tub which should set the bar for the level of kiln being built. Some of the hardware arrangements could be tweaked for safety and we insist that any current-carrying screw is safely mounted inside an enclosure which can’t be opened without tools. There’s good advice about grounding the container if metal is used. The explanation of PID loops can be ignored.

What else can you do with a kiln? How about jewelry, heat treating metal, or recycle your beer cans into an engine.

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The Internet Of Blast Gates

December 11, 2017 by Brian Benchoff 22 Comments

There’s nothing quite like building out a shop filled with tools, but even that enviable task has a lot of boring work that goes into it. You’ve got to run power, you’ve got to build benches, and you need to build a dust collection system. That last one is usually just fitting a bunch of pipe and tubes together and adding in a few blast gates to direct the sucking of your dust collection system to various tools around the shop.

For most shops with a handful of tools and dust collection ports, manually opening and closing each blast gate is an annoying if necessary task. What if all of this was automated, though? That’s what [Bob] over on I Like To Make Stuff did. He automated his dust collection system. When a tool turns on, so does the vacuum, and the right blast gate opens up automatically.

The first part of this build is exactly what you would expect for installing a dust collection system in a shop. The main line is PVC sewer pipe tied to the rafters. Yes, this pipe is grounded, and s otherwise not very interesting at all. The real fun comes with the bits of electronics. [Bob] modified standard blast gates to be servo-actuated. Each individual tool was wired up to a current sensor at the plug, and all of this was connected to an Arduino. With a big ‘ol relay attached to the dust collection system, the only thing standing in the way of complete automation was a bit of code.

This project is a continuation of [Bob]’s earlier Arduinofication of his dust collection system where all the blast gates were controlled by servos, an Arduino, and a numeric keypad. That’s an exceptionally functional system that gets around the whole ‘leaning over a machine to open a gate’ problem, but it’s still not idiot-proof – someone has to press a button to open a gate. This new system is, for the most part, completely automatic and doesn’t really require any thought on the part of the operator. It’s neat stuff, and a great application of cheap Arduinos to make shop life a bit easier.

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Curbside Mower Gets Electric Transplant

December 8, 2017 by Tom Nardi 28 Comments

There’s few things more exciting to a hacker or maker than seeing a piece of hardware on the curb. An old computer, an appliance, maybe if you’re really lucky some power tools. So we can only imagine the rush that known lawn equipment aficionado [AmpEater] had when he saw a seemingly intact push mower in the trash. The pull start was broken on the gas engine, but where this mower was going, it wouldn’t need a gas engine.

When he got the mower back to his garage, he started on the process of converting it over to electric. Of course this means basically everything but the wheels, handle, and deck would get tossed. But starting with a trashed gas mower still sounds a lot easier compared to trying to figure out how to make or source a wheeled mower deck.

Step one in this conversion was stripping all the paint off the deck and welding a plate over where the original gas engine was. [AmpEater] then 3D printed some mounts to hold the DeWalt tool batteries he would be using as a power source, taking the extra time to align everything so it would have the look of an old flathead gasoline engine. A tongue-in-cheek reference to the mower’s old gasoline gulping days, and an awesome little detail that gives the final product a great look.

The controller is a commercial model intended for electric bikes, and the heart of this new mower is a brushless direct-drive motor capable of 3,000 RPM at 40 A. [AmpEater] reports a respectable one hour run time with the six DeWalt batteries, and more power than his store-bought Ryobi electric mower.

If the name [AmpEater] looks familiar, it’s because this isn’t the first time he’s graced us with a mower conversion: back in 2013 he impressed us with his solar-electric Cub Cadet zero-turn. This build isn’t quite as slick as the Cub Cadet, but the much lower cost and difficulty level means that you may be able to follow in his footsteps even if you don’t have his Zeus-level mastery of the electric motor.

As electric mowers have gotten more popular, we’ve seen an increasing flow of hacks and mods for them. Everything from replacing the batteries to turning them into something else completely.

Print A Plywood Bending Jig

December 6, 2017 by Kristina Panos 10 Comments

Ever wanted to bend plywood but don’t have the equipment or the space to use it? Whatever the issue, dust off those project ideas and take a look at [Ryo Kosaka]’s experimental bending jig.All you need are some boards, a couple of fasteners, and [Ryo]’s 3-D printed connectors.

This is quite the elegant solution for bending in a small space with little noise. The main departure from standard bending methods is that instead of making the bend by clamping the veneers between a pair of positive and negative mold halves, most of the clamping pressure comes from air pumped into a rubber ball. That’s not even the best part: not only is the mold reconfigurable, it’s modular. Want another bend in your thing? Just print another connector and grab another piece of wood.

[Ryo]’s pivoting connectors screw into the end of one board and move freely along the length of a second board. Once the bend angle is dialed up, he locks it in place with a bolt. For the first test, [Ryo] made a lamp base with two bends.The jig worked great except for a small gap that didn’t get enough clamping pressure from the ball. We wonder if rotating the jig during the process would have let gravity address the issue. For the second test, [Ryo] added another piece to make the jig rectangular and made a floating wall shelf. Bend your way past the break for the video version.

In making the lamp base, [Ryo] found it easier to pre-bend the veneers with a heat gun. If the project were smaller, he could have softened up the wood in a microwave.

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