Build Your Own Vacuum Chamber For Degassing And More

April 12, 2019 by Lewin Day 23 Comments

A vacuum chamber can be a useful thing to have around the shop. It can be used for all manner of purposes, from science experiments to degassing paints and epoxies. They’re not something you’d find in every workshop, but never fear – you can always build one from scrap you’ve got lying around! (YouTube video, embedded below.)

[VegOilGuy] begins the build with a simple plywood box, which gets screwed together and then tarted up with bodyfiller and paint. This helps to make the box airtight, as well as improving the aesthetics. A slot is then cut in the lid, and then filled with an excessive amount of silicone sealant. A flat plate covered in aluminium foil is placed on top, and the silicone is left to cure for several days.This is used to create a flat sealing surface for the lid to be placed on later.

Once the seal is complete, it’s a simple plumbing job to finish the chamber. [VegOilGuy] does a great job of demonstrating copper soldering and the proper way to install the necessary taps and check valves. Combined with an electric pump, the vacuum chamber passes its tests with flying colors, completely ruining some marshmallows in the process.

With a few dollars spent online for the special bits, it’s a build that any handy maker could throw together in a weekend. You can always go another route, though – like using an old fridge compressor to get the job done.

[Thanks to Keith O for the tip!]

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This Bike Pump Now Sucks

April 11, 2019 by Lewin Day 18 Comments

Pulling a vacuum is something every proud maker must do once in a while. Whether you’re degassing epoxy or vacuum forming parts, you’ll need a reliable pump to get the job done. [drcrash] has just the guide to help – on how to convert a regular handpump to vacuum duty. (Video embedded after the break.)

[drcrash] recommends starting with a Slime brand 2060-A pump or similar. It’s a basic hand pump, with no pressure gauges or other frills to get in the way. It’s also got a strong steel shaft that can hold up to repeated use. You’ll also need some tubing and a check valve to get the job done.

The basic concept is to reconfigure the pump to suck air out of things rather than blowing it into them. By removing the original check valve and installing one in the opposite direction, and reversing the pump’s piston, it’s possible to pull good vacuum without breaking a sweat. [drcrash] reports that it’s possible to go up to 11 psi below atmospheric with this setup, which is plenty for a wide range of applications. If you need to go further, you can try building your own turbomolecular pump instead.

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Now Toto’s Africa Is Stuck In Our Heads

April 1, 2019 by Brian Benchoff 24 Comments

April Fool’s Day is bad. April Fool’s Day is a terrible, horrible, no good, very bad day. For one day a year, we’re inundated with pieces that can, accurately and without any sense of irony, be called fake news. YouTube is worse. But you know what’s worse than April Fool’s Day? A hundred children playing plastic recorders. But it’s April Fool’s Day, and things must get worse. Here’s a vacuum cleaner playing Africa by Toto.

This is the latest build from [James Bruton] or [Ecks Robots Dot Co Dot UK], who is the king of building just about anything with 3D printers. He’s got a BB8 and some of the cooler Star Wars droids, a Hulkbuster, and openDog. When it comes to confabulating robotics and 3D printers, [James] is the king. But this is April Fool’s Day, and if you’re a big YouTuber, you need to do something annoying. [James] is the king.

This build uses a Henry vacuum cleaner, a canister vacuum with a silk screened face, because why not, and you’re not truly living until you put googly eyes on your Roomba. Also, all vacuums in England are Hoovers, because reasons. In collaboration with [Mothcub], [James] adapted cheap children’s plastic recorders to a Henry vacuum cleaner with a few 3D printed parts, some servo-controlled valves, and a bit of plastic tubing. While using cheap kid’s recorders as the tone generator in what is effectively a pipe organ is interesting (the stickers over the holes are a great idea), this is something that should not be done ever. This idea should not be replicated. These recorders are not in tune and I don’t know how because they’re just one piece of plastic that came out of the same mold.

The servos, and therefore the entire pipe organ, are controlled via MIDI, which makes this the first DIY MIDI pipe organ we’ve seen. It’s a proof of concept, and a pretty good one. It also sounds terrible. This is proof that cheap plastic recorders don’t sound good. The video is below, and I highly suggest skipping the second half.

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Downdraft Table Inhales Dust, Not Cash

March 14, 2019 by Tom Nardi 15 Comments

We always look forward to the builds [MakerMan] sends in, and it’s not just because we dig his choices in royalty free music (though it helps). He always manages to put together his projects with a minimum of fuss, and perhaps more importantly, a minimum of funds. His builds use salvaged components, easily sourced materials, and common tools. Watching him work invariably makes us realize that we tend to overthink our own projects.

In his latest video, [MakerMan] was tasked with building a downdraft table for a local factory that makes jewelry boxes. By sucking air through a series of holes in the table’s surface, sawdust created while the workers are building the boxes will automatically be removed from the workspace. Even if you aren’t in the jewelry box making business, any task which produces fine particles (such as sanding) could benefit from such a setup. You probably won’t need a downdraft table quite as large as the one he builds, but the principles will be the same if you get inspired to build a somewhat smaller version.

The build starts with sheets of MDF, which get cut, glued, and screwed together to make the basic tabletop shape. To this, [MakerMan] attaches a welded steel frame which will give it the strength MDF itself lacks. With careful measurement, lines are plotted across the top of the MDF sheet and all the holes are drilled with a simple hand drill; no fancy CNC here.

With the table doing its best colander impression, [MakerMan] adds an air box to the bottom which is similarly made of thin MDF sheets. All of the joints are sealed up with caulk, because at this point you want things to be as air tight as possible. A large blower is attached to the bottom, which gets piped to a dust collection system that’s made of a garbage can and…you guessed it, more MDF.

Watching [MakerMan] turn what’s often literal trash into a functional build never gets old. We’ve seen him create everything from a gorgeous origami chandelier to a very impressive diode laser cutter using little more than scrap parts and hand tools, and we can’t wait to see what he comes up with next.

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Vacuum-Powered Rotary Tool Redux, This Time Machined

February 28, 2019 by Dan Maloney 18 Comments

We love to see projects revisited, especially when new materials or methods make it worth giving the first design another go around. This twin-turbine vacuum-powered Dremel tool is a perfect example of what better tools can do for a build.

You may recall [JohnnyQ90]’s first attempt at a vacuum powered rotary tool. That incarnation, very similar in design to the current work, was entirely 3D-printed, and caused no little controversy in the comments about the wisdom of spinning anything made on an FDM printer at 43,000 RPM. Despite the naysaying, [Johnny] appears to have survived his own creation. But the turbo-tool did have its limitations, including somewhat anemic torque. This version, machined rather than printed and made almost completely from aluminum, seems to have solved that problem, perhaps thanks to the increased mass of the rotating parts. The twin rotors and the stator were milled with a 5-axis CNC machine, which has been a great addition to [JohnnyQ90]’s shop. The turbine shaft, looking like something from a miniature jet engine, was meticulously balanced using magnets mounted in the headstock and tailstock of a lathe. The video below shows the build and a few tests; we’re not big fans of the ergonomics of holding the tool on the end of that bulky hose, but it sure seems to work well. And that sound!

We first noticed [JohnnyQ90] when he machined aluminum from soda cans to make a mini Tesla turbine. His builds have come a long way since then, and we look forward to what he’ll come up with next.

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In Space, No One Can Hear You Explode: The Byford Dolphin Incident

February 15, 2019 by Al Williams 47 Comments

“It wouldn’t happen that way in real life.” One of the most annoying habits of people really into the “sci” of sci-fi is nitpicking scientific inaccuracies in movies. The truth is, some things just make movies better, even if they are wrong.

What would Star Wars be without the sounds of an epic battle in space where there should be no sound? But there are plenty of other examples where things are wrong and it would have been just as easy to get them right — the direction of space debris in the movie Gravity, for example. But what about the age-old trope of explosive decompression? Some movies show gross body parts flying everywhere. Others show distressed space travelers surviving in space for at least brief periods.

It turns out, dropping pressure from one atmosphere to near zero is not really good for you as you might expect. But it isn’t enough to just make you pop like some meat balloon. You are much more likely to die from a pulmonary embolism or simple suffocation. But you are a meat balloon if you experience a much greater change in pressure. How do we know? It isn’t theoretical. These things have happened in real life.

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A Crash Course In 3D Printed Venturi Pumps

February 8, 2019 by Tom Nardi 15 Comments

Venturi pumps, commonly referred to as aspirators, are a fantastic way of moving around things which you might not want spinning around inside of a pump, and one of the easiest ways to create a vacuum. According to his research, [Tuval Ben Dosa] believed such a device would be a good way to move corrosive gasses which would normally eat up a blower fan; all he had to do was figure out how to 3D print one to his specifications.

Put simply: if you take a “T” shaped pipe and pass a fluid (such as air or water) through the straight section, a vacuum will be created on the shorter side due to the Venturi effect. As long as you don’t mind the substance you wish to pump getting mixed into your working fluid, it’s a simple way to bring something “along for the ride” as the fluid makes its way through the pipe.

[Tuval] needed a way to remove the chlorine gasses produced by his PCB etching station, and an aspirator seemed like the perfect solution. He just needed to pump clean air through a Venturi, which would suck up the chlorine gas on the way through, and ultimately carry it outside. But he soon found that while a pump based on the Venturi effect is simple conceptually, getting it to work in the real world is a bit trickier. Especially when you’re dealing with something like 3D printing, which brings in its own unique challenges.

He tried modeling a few designs he found online in 3D and printing them out, but none of them worked as expected. The most common problem was simply that no vacuum was being generated, air was freely moving out of both sides. While [Tuval] doesn’t claim to have any great knowledge of fluid dynamics, he reasoned that the issue was due to the fact that most Venturi pumps seem designed to move water rather than air. So he designed a new version of the pump which had a more pronounced nozzle on the inlet surrounded by a cavity in which the gases could mix.

His modified design worked, and now anyone with a 3D printer can run off their own Venturi device for quickly and easily giving potentially harmful fumes or gases the boot. If this is one of those things you’d feel more comfortable buying than building, don’t worry, we’ve previously covered using a low-cost aspirator as a vacuum source in the home lab.