PCB Hotplate Has Integrated Heating Element Traces

November 16, 2022 by Lewin Day 13 Comments

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.

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DIY Streamdeck Helps You Professionalize Your Twitch Show

November 12, 2022 by Lewin Day 4 Comments

The one thing that separates the pros on Twitch from the dilettantes is the production values. It’s all about the smooth transitions, and you’ll never catch the big names fiddling with dodgy software mid-stream. The key to achieving this is by having a streamdeck to help control your setup, like this straightforward design from [Electronoobs]. (Video, embedded below.)

The build relies on an Arduino Micro, which is a microcontroller board perfectly equipped to acting as a USB macro keyboard. It’s paired with a Nextion LCD touchscreen that displays buttons for various stream control features, like displaying a “Be Right Back” screen or cuing up video clips. The build also features bigger regular buttons for important quick-access features like muting a mic. It’s all wrapped up in a 3D printed housing, with some addressable RGB LEDs running off another Arduino to add some pizazz. The neat trick is that the build sends keycodes for F13-F24, which allows for the streamdeck’s hotkeys to avoid conflicting with any other software using conventional keyboard hotkeys.

It’s a useful tool that would be of use to anyone streaming on Twitch or other platforms. Alternatively, you could repurpose an old phone to do a similar job. Video after the break.

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Bicycle Inner Tube Becomes Rugged Pencil Case

November 12, 2022 by Lewin Day 23 Comments

If you’re a cyclist that lives in an area with poorly-maintained infrastructure, you’ll likely have plenty of punctured inner tubes begging for reuse. Consider crafting them into a rugged, hard-wearing pencil case with this design from [Yorkshire Lass].

[Yorkshire Lass] does a great job of not only explaining the basic design of the pencil case, but also the unique techniques required to work with inner tubes in this manner. For best results, the tube must first be straightened by stretching it for some time along a flat board. Strips of the rubber must then be cut to suit, and then assembled into the pattern to make the pencil case. Sewing up the case also requires some special techniques outside those used in regular sewing. That’s largely down to the fact that rubber can’t be pinned in place without leaving a permanent hole in the material. Thankfully, the write-up explains all the traps for those new to sewing inner tubes, which we’d have to suspect is most of us.

Assembled properly, you’ll end up with a pencil case made of far tougher material than most. Plus, it makes a great fashion accessory to flaunt to other bicycle or recycling evangelists at your school, college, or workplace. Even better, there’s scope to run a group craft session with your local bike group given everyone surely has a few dud mountain bike tubes laying around.

We’ve seen some other neat hacks intended to store pens and pencils around the workshop. Meanwhile, if you’ve got your own great reuse ideas for old bicycle inner tubes, do drop us a line!

3D Printer Repurposed For Light-Duty Lab Automation Tasks

November 11, 2022 by Dan Maloney 3 Comments

Laboratory automation equipment is expensive stuff, to such a degree that small labs are often priced out of the market. That’s a shame, because there are a lot of tedious manual tasks that even modest labs would benefit from automating. Oh well — that’s what grad students are for.

But it actually isn’t that hard to bring a little automation to the lab, if you follow the lead of [Marco], [Chinna], and [Vittorio] and turn a 3D printer into a simple lab robot. That’s what HistoEnder is — a bog-standard Creality Ender 3 with a couple of special modifications that turn it into a tool for automating histology slide preparation. Histology is the study of the anatomy of tissues and uses various fixing and staining techniques to make microscopic features visible. In practice, this means moving baskets of glass slides back and forth between jars of different solutions, a job that’s perfect for a simple Cartesian gantry lab robot with a small work envelope and light loads.

None of the printer modifications are permanent; the 3D printed accessories — a hook for the slide basket and a carrier for standard histology staining jars — can quickly come off the printer to return it to its regular duty. All it takes to run HistoEnder is a bit of custom G-code and some careful alignment of the jar carrier on the print bed. We suppose the bed heater could even be used to warm up the fixing and staining solutions. There’s a brief video of HistoEnder in action embedded in the tweet below.

This isn’t the first time this team has repurposed technology for the lab — remember the fitness band that was turned into an optical densitometer?

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Chevron Desk Takes Advantage Of Plywood For Patterning

November 8, 2022 by Lewin Day 23 Comments

Buying a desk is all well and good, but [WoodCraftly] found that the options they found online were too pricey for what was being offered. Buying the table frame from scratch was much cheaper, and just required crafting a top to match. That provided the opportunity to create this beautiful herringbone-finish desk created with some simple woodworking techniques.

Plenty of clamps were needed for the glue-up.

The build starts with a motorized corner desk frame that can be bought from amazon for just $550. To create the chevron-finish top, [WoodCraftly] grabbed some plywood sheets, and cut them into a series of 1-inch strips. These were then flipped 90-degrees onto their side, and glued together to create a panel that showed off the individual layers of the plywood. This panel was then cut into 3-inch wide strips at a 45-degree angle, and these strips were then placed back to back and once again glued up to create the attractive herringbone design.

From there, it was a simple matter of gluing up panels into the L-shape required for the desk, adding mounting holes, and rounding off the corners for a nice finish. The desk was also given a thick coat of epoxy on the bottom which soaked into the wood and helped give the desk some strength, and a top coat that was sanded back to a natural-look finish.

Overall, the final desk is just the product of some smart cutting and gluing steps combined to create a fun pattern in the end. It’s always fun to build your own furniture because you can express your own style in your creations. Video after the break.

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Overengineered Fume Extractor, Version 2

November 7, 2022 by Al Williams 12 Comments

We all know the temptation of adding one more feature to your latest project. [Arnov Sharma] didn’t resist the urge. Building on his 3D-printed fume extractor, he developed a new version made of PCB material.

The device has a 18650 battery and corrects several flaws in the original design we covered earlier. In particular, the new version uses a quiet fan and consumes less power. There is also a 3D-printed filter housing that uses cotton as a filter media. Continue reading “Overengineered Fume Extractor, Version 2” →

An RP2040 Powered Pick And Place

November 7, 2022 by Matthew Carlson 15 Comments

Pick and place machines are a wonder to behold, as they delicately and accurately place part after part. Unfortunately, they have to have a similarly wondrous price tag. Luckily, they aren’t too difficult to make yourself as they share many properties of a 3D printer with some extra constraints. [Stargirl Flowers] released Starfish, an open-source pick-and-place control board based around an RP2040 to help people make their own.

She purchased a LumenPnP, and the itch to tinker became too much to ignore. The STM32 on the stock controller also happened to get fried, leaving an obvious opening to create a custom board. [Stargirl] chose Trinamic TMC2209 motor controllers to drive the three stepper motors. The power circuit is impressively overbuilt with a 3A fuse, a TVS diode for shunting voltage spikes, a P-channel MOSFET for reverse polarity protection, a low-pass filter for AC ripple, and a large 100μF capacitor.

The RP2040 is a good choice since it’s easy to get and has plenty of digital I/O. USB connects the board to the outside work and includes ESD TVS diodes to protect the board when connecting and disconnecting the USB port. Motors for vacuums are controlled by a 74HC2G34 buffer that drives enable lines to two MOSFETs. Solenoids are similar but with a high current peak and a much smaller current to keep them open. The DRV120 fits the bill as it is a single-channel relay with current regulation. I2C vacuum sensors are the same ones on the Lumen motherboard; they just required an I2C multiplexer.

It’s an extremely well-documented project explaining why each part was chosen and why. If you want to create an RP2040 project that needs to last, we consider this a guiding star. It’s all up on GitHub for you to take a look at.

This isn’t the first time we’ve seen RP2040 as part of a motor controller, and we suspect we’ll see more.