Portable Solder Paste Station Prevents Smears With Suction

October 30, 2024 by Danie Conradie 28 Comments

Applying solder paste to a new custom PCB is always a little nerve-racking. One slip of the hand, and you have a smeared mess to clean up. To make this task a little easier, [Max Scheffler] built the Stencil Fix Portable, a compact self-contained vacuum table to hold your stencil firmly in place and pop it off cleanly every time.

The Stencil Fix V1 used a shop vac for suction, just like another stencil holder we’ve seen. The vacuum can take up precious space, makes the jig a little tricky to move, and bumping the hose can lead to the dreaded smear and colorful language. To get around this [Max] added a brushless drone motor with a 3D printed impeller, with a LiPo battery for power. The speed controller gets its PWM signal from a little RP2040 dev board connected to a potentiometer. [Max] could have used a servo tester, but he found the motor could be a little too responsive and would move the entire unit due to inertia from the impeller. The RP2040 allowed him to add a low pass filter to eliminate the issue. The adjustable speed also means the suction force can be reduced a little for easy alignment of the stencil before locking it down completely.

We love seeing tool projects like these that make future projects a little easier. Fortunately, [Max] made the designs available so you can build your own.

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On The Nature Of Electricity: Recreating The Early Experiments

October 3, 2024 by Dan Maloney No comments

Bits of material levitating against gravity, a stream of water deflected by invisible means, sparks of light appearing out of thin air; with observations like those, it’s a wonder that the early experiments into the nature of electricity progressed beyond the catch-all explanation of magic. And yet they did, but not without a lot of lamb’s bladders and sulfur globes, and not a little hand waving in the process. And urine — lots and lots of urine.

Looking into these early electrical experiments and recreating them is the unlikely space [Sam Gallagher] has staked out with the “Experimental History of Electricity,” a growing playlist on his criminally undersubscribed YouTube channel. The video linked below is his latest, describing the apparatus one Francis Hauksbee used to generate static electric charges for his early 18th-century experiments. Hauksbee’s name is nowhere near as well-known as that of Otto von Guericke or William Gilbert, who in the two centuries before Hauksbee conducted their own experiments and who both make appearances in the series. But Hauksbee’s machine, a rotating glass globe charged by the lightest touch of a leather pad, which [Sam] does a fantastic job recreating as closely as possible using period-correct materials and methods, allowed him to explore the nature of electricity in much greater depth than his predecessors.

But what about the urine? As with many of the experiments at the time, alchemists used what they had to create the reagents they needed, and it turned out that urine was a dandy source of phosphorous, which gave off a brilliant light when sufficiently heated. The faint light given off by mercury when shaken in the vacuum within a barometer seemed similar enough that it became known as the “mercurial phosphor” that likely inspired Hauksbee’s electrical experiments, which when coupled with a vacuum apparatus nearly led to the invention of the mercury discharge lamp, nearly 200 years early. The more you know. Continue reading “On The Nature Of Electricity: Recreating The Early Experiments” →

Welding Wood Is As Simple As Rubbing Two Sticks Together

July 21, 2024 by Dan Maloney 12 Comments

Can you weld wood? It seems like a silly question — if you throw a couple of pieces of oak on the welding table and whip out the TIG torch, you know nothing is going to happen. But as [Action Lab] shows us in the video below, welding wood is technically possible, if not very practical.

Since experiments like this sometimes try to stretch things a bit, it probably pays to define welding as a process that melts two materials at their interface and fuses them together as the molten material solidifies. That would seem to pose a problem for wood, which just burns when heated. But as [Action Lab] points out, it’s the volatile gases released from wood as it is heated that actually burn, and the natural polymers that are decomposed by the heat to release these gases have a glass transition temperature just like any other polymer. You just have to heat wood enough to reach that temperature without actually bursting the wood into flames.

His answer is one of the oldest technologies we have: rubbing two sticks together. By chucking a hardwood peg into a hand drill and spinning it into a slightly undersized hole in a stick of oak, he created enough heat and pressure to partially melt the polymers at the interface. When allowed to cool, the polymers fuse together, and voila! Welded wood. Cutting his welded wood along the joint reveals a thin layer of material that obviously underwent a phase change, so he dug into this phenomenon a bit and discovered research into melting and welding wood, which concludes that the melted material is primarily lignin, a phenolic biopolymer found in the cell walls of wood.

[Action Lab] follows up with an experiment where he heats bent wood in a vacuum chamber with a laser to lock the bend in place. The experiment was somewhat less convincing but got us thinking about other ways to exclude oxygen from the “weld pool,” such as flooding the area with argon. That’s exactly what’s done in TIG welding, after all. Continue reading “Welding Wood Is As Simple As Rubbing Two Sticks Together” →

Robot Seeks And Sucks Up Cigarette Butts, With Its Feet

July 20, 2024 by Donald Papp 30 Comments

It would be better if humans didn’t toss cigarette butts on the ground in the first place, but change always takes longer than we think it should. In the meantime, researchers at the Italian Institute of Technology have used the problem as an opportunity to explore what seems to be a novel approach: attaching vacuum pickups to a robot’s feet, therefore removing the need for separate effectors.

VERO (Vacuum-cleaner Equipped RObot) is a robotic dog with a vacuum cleaner “backpack” and four hoses, one going down each leg. A vision system detects a cigarette butt, then ensures the robot plants a foot next to it, sucking it up. The research paper has more details, but the video embedded below gives an excellent overview.

While VERO needs to think carefully about route planning, using the legs as effectors is very efficient. Being a legged robot, VERO can navigate all kinds of real-world environments — including stairs — which is important because cigarette butts know no bounds.

Also, using the legs as effectors means there is no need for the robot to stop and wait while a separate device (like an arm with a vacuum pickup) picks up the trash. By simply planting a foot next to a detected cigarette butt, VERO combines locomotion with pickup.

It’s fascinating to see how the Mini Cheetah design has really become mainstream to the point that these robots are available off-the-shelf, and it’s even cooler to see them put to use. After all, robots tackling trash is a good way to leverage machines that can focus on specific jobs, even if they aren’t super fast at it.

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Robotic Platform Turns Shop Vac Into Roomba

May 8, 2024 by Bryan Cockfield 14 Comments

The robotic revolution is currently happening, although for the time being it seems as though most of the robots are still being generally helpful to humanity, whether that help is on an assembly line, help growing food, or help transporting us from place to place. They’ve even showed up in our homes, although it’s not quite the Jetsons-like future yet as they mostly help do cleaning tasks. There are companies that will sell things like robotic vacuum cleaners but [Clay Builds] wanted one of his own so he converted a shop vac instead.

The shop vac sits in a laser-cut plywood frame and rolls on an axle powered by windshield wiper motors. Power is provided from a questionable e-bike battery which drives the motors and control electronics. A beefy inverter is also added to power the four horsepower vacuum cleaner motor. The robot has the ability to sense collisions with walls and other obstacles, and changes its path in a semi-random way in order to provide the most amount of cleaning coverage for whatever floor it happens to be rolling on.

There are a few things keeping this build from replacing anyone’s Roomba, though. Due to the less-than-reputable battery, [Clay Builds] doesn’t want to leave the robot unattended and this turned out to be a good practice when he found another part of the build, a set of power resistors meant to limit current going to the vacuum, starting to smoke and melt some of the project enclosure. We can always think of more dangerous tools to attach a robotic platform to, though.

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More Microwave Metal Casting

April 16, 2024 by Dan Maloney 10 Comments

If you think you can’t do investment casting because you don’t have a safe place to melt metal, think again. Metal casting in the kitchen is possible, as demonstrated by this over-the-top bathroom hook repair using a microwave forge.

Now, just because it’s possible doesn’t mean it’s advisable. There are a lot better ways to fix something as mundane as a broken bathroom hook, as [Denny] readily admits in the video below. But he’s been at the whole kitchen forging thing since building his microwave oven forge, which uses a special but easily constructed ceramic heat chamber to hold a silicon carbide crucible. So casting a replacement hook from brass seemed like a nice exercise.

The casting process starts with a 3D-printed model of the missing peg, which gets accessories such as a pouring sprue and a thread-forming screw attached to it with cheese wax. This goes into a 3D-printed mold which is filled with a refractory investment mix of plaster and sand. The green mold is put in an air fryer to dry, then wrapped in aluminum foil to protect it while the PLA is baked out in the microwave. Scrap brass gets its turn in the microwave before being poured into the mold, which is sitting in [Denny]’s vacuum casting rig.

The whole thing is over in seconds, and the results are pretty impressive. The vacuum rig ensures metal fills the mold evenly without voids or gaps. The brass even fills in around the screw, leaving a perfect internal thread. A little polishing and the peg is ready for bathroom duty. Overly complicated? Perhaps, but [Denny] clearly benefits from the practice jobs like this offer, and the look is pretty cool too. Still, we’d probably want to do this in the garage rather than the kitchen.
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Rosie The Robot Runs For Real

March 9, 2024 by Al Williams 2 Comments

On the recent 256th episode of the Hackaday podcast, [Kristina] mentioned her favorite fictional robot was Rosie from The Jetsons. [Robert Zollna] must agree since he built a reimagined Rosie and it even caught the notice of mainstream outlet People magazine.

We didn’t find much information outside of the TikTok video (see below; you can use the Guest button if you don’t have an account). However, there were a few clever ideas here. First, the robot mechanism is actually Rosie’s vacuum cleaner. Like a tail wagging a dog, an off-the-shelf floor vac tows the robot body.

Rosie herself is clearly an office chair base with an artistic body. The head rotates, and the mouth appears to open and close, so there’s apparently a little more electronics inside, but that’s nothing you couldn’t throw together with some RC servos and an ESP32.

Some videos cover the build so you might be able to glean more details, but the bite-sized videos aren’t very descriptive even though they are fun to watch. If you thought folks documenting their projects on YouTube was bad, you’re really gonna love the TikTok generation.

We like the look of Rosie, but as a practical matter, we need our robot vac to be smaller, not larger. However, using these off-the-shelf robots as a quick start for a robotics project is reasonable. Especially if you can pick up one cheap. Not that that’s a new idea. They even make stripped-down units with the intent that you don’t want to use them as cleaners.

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