Even if surface-mount skills aren’t in your repertoire, chances are pretty good that most of us are at least familiar with SMD stencils. These paper-thin laser-cut steel sheets are a handy way to apply a schmear of solder paste to the pads of a PCB before component placement and reflowing. But are stencils good for anything else?
It turns out they are, if you’ve got some plain old 8×8 LED matrix displays you want to jazz up a bit. In this case, [upir]’s displays were of the square pixel type, but this trick would work just as well for a matrix with circular elements. Most of the video below is a master class in Adobe Illustrator, which [upir] used to generate the artwork for his stencils. There are a lot of great tips here that make creating one simple shape and copying it over the whole array with the proper spacing a lot easier. He also details panelizing multiple stencils, as well as the workflow from Illustrator to manufacturing.
When lined up properly over the face of the LED matrix, the stencils have quite an effect. We really liked the narrow vertical bars, which make the LED display look a bit like a VFD. And just because [upir] chose to use the same simple shape over all the LEDs in a matrix doesn’t mean that there aren’t other options. We can see how you might use the same technique to create different icons or even alphanumeric characters to create custom LED displays. The possibilities are pretty much limited to your imagination.
This isn’t the first time we’ve seen [upir] teaching old displays new tricks.
Continue reading “LED Matrix Displays Get New Look Thanks To SMD Stencils” →
One of the first tools that is added to a toolbox when working on electronics, perhaps besides a multimeter, is a soldering iron. From there, soldering tools can be added as needed such as a hot air gun, reflow oven, soldering gun, or desoldering pump. But often a soldering iron is all that’s needed even for some specialized tasks as [Mr SolderFix] demonstrates.
This specific technique involves removing a large connector from a PCB. Typically either a heat gun would be used, which might damage the PCB, or a tedious process involving a desoldering tool or braided wick might be tried. But with just a soldering iron, a few pieces of wire can be soldered around each of the pins to create a massive solder blob which connects all the pins of the connector to this wire. With everything connected to solder and wire, the soldering iron is simply pressed into this amalgamation and the connector will fall right out of the board, and the wire can simply be dropped away from the PCB along with most of the solder.
There is some cleanup work to do afterwards, especially removing excess solder in the holes in the PCB, but it’s nothing a little wick and effort can’t take care of. Compared to other methods which might require specialized tools or a lot more time, this is quite the technique to add to one’s soldering repertoire. For some more advanced desoldering techniques, take a look at this method for saving PCBs from some thermal stresses.
Continue reading “Finessing A Soldering Iron To Remove Large Connectors” →
Shape shifters have long been the stuff of speculative fiction, but researchers in China have developed a magnetoactive phase transitional matter (MPTM) that makes Odo slipping through an air vent that much more believable.
Soft robots can squeeze into small spaces or change shape as needed, but many of these systems aren’t as strong as their more mechanically rigid siblings. Inspired by the sea cucumber’s ability to manipulate its rigidity, this new MPTM can be inductively heated to a molten state to change shape as well as encapsulate or release materials. The neodymium-iron-boron (NdFeB) microparticles suspended in gallium will then return to solid form once cooled.
Applications in drug delivery, foreign object removal, and smart soldering (video after the break) probably have more real world impact than the LEGO minifig T1000 impersonation, despite how cool that looks. While a pick-and-place can do better soldering work on a factory line, there might be repair situations where a magnetically-controlled solder system could come in handy.
We’ve seen earlier work with liquid robots using gallium and bio-electronic hybrids also portending the squishy future of robotics.
Continue reading “Phase Change Materials For Flexible And Strong Robots” →
Normally when we talk about PCBs and hotplates, we’re talking about reflowing solder. In this build from [Arnov Sharma], though, the PCB itself is the hotplate!
The idea was to create a compact hotplate for easily reflowing small PCBs. To achieve that, [Arnov] designed a board with a thick coil trace that acts as a heating element. The full coil trace has a resistance of 1.9 ohms, and passing electricity through it generates plenty of heat. Running off a 12 volt supply, the mini hotplate is capable of reaching a maximum temperature of 214°C. Higher voltages can push that figure higher.
The board is intended to self-regulate, with an ATtiny13 onboard and a thermistor to measure temperature. However, in the initial design, this feature didn’t quite work properly. Version 2 is intended to include a better temperature sensor and a OLED screen for displaying the current temperature to the user.
We’ve seen other tiny hotplate builds before, too. They’re great for smaller projects and for hacking on the go! Video after the break.
Continue reading “PCB Hotplate Has Integrated Heating Element Traces” →
[Ted Yapo] shared a method of easily and conveniently soldering to aluminum, which depends on a little prep work to end up only slightly more complex than soldering to copper. A typical way to make a reliable electrical connection to aluminum is to use a screw and a wire, but [Ted] shows that it can also be done with the help of an abrasive and mineral oil.
Aluminum doesn’t solder well, and that’s because of the oxide layer that rapidly forms on the surface. [Ted]’s solution is to scour the aluminum with some mineral oil. The goal is to scrape away the oxide layer on the aluminum’s surface, while the mineral oil’s coating action prevents a new oxide layer from immediately re-forming.
After this prep, [Ted] uses a hot soldering iron and a blob of solder, heating it until it sticks. A fair bit of heat is usually needed, because aluminum is a great heat conductor and tends to be lot thicker than a typical copper ground plane. But once the aluminum is successfully tinned, just about anything can be soldered to it in a familiar way.
[Ted] does caution that mineral oil can ignite around 260 °C (500 °F), so a plan should be in place when using this method, just in case the small amount of oil catches fire.
This looks like a simple technique worth remembering, and it seems easier than soldering by chemically depositing copper onto aluminum.
The original Game Boy was the greatest selling handheld video game system of all time, only to be surpassed by one of its successors. It still retains the #2 position by a wide margin, but even so, they’re getting along in years now and finding one in perfect working condition might be harder than you think. What’s more likely is you find one that’s missing components, has a malfunctioning screen, or has had its electronics corroded by the battery acid from a decades-old set of AAs.
That latter situation is where [Taylor] found himself and decided on performing a full restoration on this classic. To get started, he removed all of the components from the damaged area so he could see the paths of the traces. After doing some cleaning of the damage and removing the solder mask, he used 30 gauge wire to bridge the damaged parts of the PCB before repopulating all of the parts back to their rightful locations. A few needed to be replaced, but in the end the Game Boy was restored to its former 90s glory.
This build is an excellent example of what can be done with a finely tipped soldering iron while also being a reminder not to leave AA batteries in any devices for extended periods of time. The AA battery was always a weak point for the original Game Boys, so if you decide you want to get rid of batteries of any kind you can build one that does just that.
Continue reading “Acid-Damaged Game Boy Restored” →
We have certainly all had our moments with solder paste. Some of us hate it; it’s sticky and gooey, and it gets everywhere. That is, unless you have a solder paste dispenser. The trouble with these is that they typically require the use of an air compressor, which can be cumbersome to haul around in certain situations. If you need a solder paste dispenser that fits conveniently where air compressors won’t, take a look at this small one from [Nuri Engineer] called the solderocket.
This design foregoes the traditional compressor in favor of pressurized carbon dioxide canisters. These are common enough and used for things like rapidly inflating bicycle tires, but for this more delicate procedure the pressurized gas needs to be handled more daintily. A rotary knob is attached to the canister to regulate pressure, and a second knob attached to a microcontroller adjusts the amount of time the air pressure is applied to the solder paste. With this small compact setup, any type of paste can be delivered to a PCB without needing to use messy stencils or needing larger hardware like a compressor.
This could be just the tool that you need if you regularly work with surface-mount components. Of course there are other methods of dispensing solder paste that don’t require any compressed gas of any kind, but as long as something is around that gets the job done, we can’t really argue with either method.