Making An Injection Mold For Yourself

August 28, 2023 by 29 Comments

Injection molding is the obvious onward step from 3D printing when the making of a few plastic parts becomes their series manufacture. The problem with injection molding is though, that making a mold can be prohibitively expensive. Has the advent of affordable CNC machining changed that? [Teaching Tech] takes a look, and machines a mold for part of a bicycle bracket.

With a diversion into home-made silicone seals for the injection molding machine, he proceeds to machine the mold itself from a block of aluminium. It’s a basic introduction to mold construction for those of us who’ve never ventured in this direction before, and it provides some interesting lessons. As we’d expect he does a rough machining pass before returning with a ball-end tool to smooth off those curves, but there’s a lesson in measuring rather than believing the paperwork. The tool he used was a bit smaller then the spec, so his path left some rough edges that had to be returned to. Otherwise the use of a removable pair of bolts to form holes in the finished part is we guess obvious after watching the video, but it’s something we learned as injection molding newbies.

This video follows on from a previous one we also covered, in which we’re introduced to the machine itself.

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Photography Goes Leaf Green

August 28, 2023 by 4 Comments

Something that haunts film photographers is the prospect of a film shortage. This won’t replace film in that event, but [Applied Science] demonstrates photography using leaves. That’s right, a plant can record an image on its leaves.

Anyone with a high-school level of education can tell you that the leaf is a solar energy harvester, with the green chlorophyll using CO2 scavenged from the air to make sugars in the presence of light. It stands to reason that this light sensitivity could be used to capture images, and indeed if you place a leaf in the dark for an extended period of time its chlorophyll fades away where there is no light. The technique described in the video below the break is different though, and much more sensitive than the days-long exposures required to strip chlorophyll. It relies on starch, which the leaf uses to store energy locally when it has an excess of light. Continue reading “Photography Goes Leaf Green” →

The Device That Won WW2: A History Of The Cavity Magnetron

August 28, 2023 by 55 Comments

[Curious Droid] is back with a history lesson on one of the most important inventions of the 20th century: The cavity magnetron. Forged in the fighting of World War II, the cavity magnetron was the heart of radar signals used to identify attacking German forces.

The magnetron itself was truly an international effort, with scientists from many countries providing scientific advances. The real breakthrough came with the work of  [John Randall] and [Harry Boot], who produced the first working prototype of a cavity magnetron. The device was different than the patented klystron, or even earlier magnetron designs. The cavity magnetron uses physical cavities and a magnetic field to create microwave energy.  The frequency is determined by the size and shape of the cavities.

While the cavity magnetron had been proven to work, England was strapped by the war effort and did not have the resources to continue the work. [Henry Tizzard] brought the last prototype to the USA where it was described as “the most valuable cargo ever brought to our shores”. The cavity magnetron went on to be used throughout the war in RADAR systems both air and sea.

Today, many military RADAR systems use klystrons or traveling wave tube amplifiers due to requirements for accurate frequency pulses.  But the cavity magnetron still can be found in general and commercial aviation RADAR systems, as well as the microwave ovens we all know and love.

Check the video out after the break.

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Maker Faire Hannover: The Right Way To Do It

August 28, 2023 by 16 Comments

On these pages we bring you plenty of reports from events, most of which are from the hacker or hardware communities. These can be great fun to attend, but they’re not the only game in town when looking at things adjacent to our community. At what you might describe as the consumer end of the market there are the Maker Faires, which bring a much more commercial approach to a tech event. While so many of us are in Germany for Chaos Communication Camp there’s a maker faire ideally placed to drop in on the way back. We took the trip to Hannover, a large and rather pleasant city just off the Berlin to Amsterdam motorway roughly central to the top half of the country. It’s got one of the German emissions zones so without the green tax sticker in the car we took a park-and-ride on one of their clean and efficient trams to alight a short walk from the congress centre.

Plenty To See, And It’s Not All For Kids

An array of European electronic conference badges on show
Outside, a working forge
Face it, we all want a clock like this one!
Vintage test equipment
You may know Bitluni from many featured projects here.
A group of Germans who maintain a 1990s TV studio.
Hackaday’s first post, courtesy of the Wayback Machine and Makerspace Minden.

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PCB Toaster Oven Solders Your Boards

August 28, 2023 by 15 Comments

Using a toaster oven to reflow PCBs isn’t anything new, but just using a toaster oven has some limitations. Making toast isn’t as complex as reflowing PCBs. [Nabil] decided to modify an oven to get better results. In fact, this was the second iteration and involved making a custom PCB to replace the one in the oven. You can see the unit in the video below.

Of course, unless you have the exact oven (a Breville BOV450XL), you won’t want to duplicate the board, but it might give you some good ideas. The new board has a 2.8-inch capacitive LCD, an ESP32, and a few sensors and actuators.

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Review: WAINLUX K8, A Diode Laser That’s Ready To Work

August 28, 2023 by 24 Comments

Rarely a week goes by that some company doesn’t offer to send us their latest and greatest laser. You know the type — couple of aluminum extrusions, Class 4 diode flopping around in the breeze, and no enclosure to speak of unless you count the cardboard box they shipped it in. In other words, an accident waiting to happen. Such gracious invitations get sent to the trash without a second thought.

Now don’t get me wrong, I have no doubt that the average Hackaday reader would be able to render such a contraption (relatively) safe for use around the shop. Build a box around it, bolt on a powerful enough fan to suck the smoke out through the window, and you’ve turned a liability into a legitimate tool. But the fact remains that we simply can’t put our stamp on something that is designed with such a blatant disregard for basic safety principles.

The earlier WAINLUX JL4 — lucky rabbit foot not included.

That being the case, a recent email from WAINLUX nearly met the same fate as all those other invitations. But even at a glance it was clear that this new machine they wanted to send out, the K8, was very different from others we’d seen. Different even from what the company themselves have put out to this point. This model was fully enclosed, had a built-in ventilation fan, an optional air filter “sidecar”, and yes, it would even turn off the laser if you opened the door while it was in operation. After reading through the promotional material they sent over, I had to admit, I was intrigued.

It seemed like I wasn’t the only one either; it was only a matter of days before the Kickstarter for the WAINLUX K8 rocketed to six figures. At the time of this writing, the total raised stands at just under $230,000 USD. There’s clearly a demand for this sort of desktop laser, the simplicity of using a diode over a laser tube is already appealing, but one that you could actually use in a home with kids or pets would be a game changer for many people.

But would the reality live up to the hype? I’ve spent the last couple of weeks putting a pre-production WAINLUX K8 through its paces, so let’s take a look and see if WAINLUX has a winner on their hands.

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Close-up of a magnetic tentacle robot next to a phantom bronchiole (Credit: University of Leeds)

The Healing Touch Of Magnetic Tentacles In Photothermal Lung Cancer Therapy

August 28, 2023 by 11 Comments

Of the body’s organs, the lungs are among the trickiest to take a biopsy and treat cancer in, both due to how important they are, as well as due to their inaccessibility. The total respiratory surface within the average human lungs is about 50 to 75 square meters. Maneuvering any kind of instrument down the endless passages to reach a suspicious area, or a cancerous region to treat is nearly impossible. This has so far left much of the lungs inaccessible.

The standard of care for lung cancer is generally surgical: remove parts of the lung tissue. However, a proposed new method using magnetic tentacles may soon provide a more gentle approach, as described in Nature Engineering Communications by Giovanni Pittiglio and colleagues (press release).

The tentacles are made out of a silicone substrate with embedded magnets that allow for it to be steered using external magnetic sources. With an embedded laser fiber, the head of the tentacle can be guided to the target area, and the cancerous tissue sublimated using an external laser source. In experiments on cadavers with this system, the researchers found that they could enter 37% deeper into the lungs than with standard equipment. The procedure was also completed with less tissue displacement.

Considering the high fatality rate of lung cancers, the researchers hope that this approach could soon be turned into a viable therapy, as well as for other medical conditions where a gentle tentacle slithering into the patient’s body could effect treatments previously considered to be impossible.

Heading image: Close-up of a magnetic tentacle robot next to a phantom bronchiole (Credit: University of Leeds)