Robert Murray-Smith

19 Articles

Honoring The Legacy Of Robert Murray-Smith

October 8, 2025 by 54 Comments

We at Hackaday are deeply saddened to learn of the passing of Robert Murray-Smith. The prolific experimenter had spent over a decade on YouTube, creating more than 2,500 videos where he gleefully demonstrated his seemingly endless collection of homemade contraptions. At least eighteen of which ended up on the pages of Hackaday since we first crossed paths with him back in 2013.

Like many of you, we were also shocked to find that Robert made the decision to end his own life. As cliché as it might sound, he simply didn’t seem like the type. His demeanor was always boisterous in his videos, exhibiting an almost child-like joy as he showed off his latest creation with a laugh and smile.

But as explained by his brother Dave in the brief announcement video posted yesterday, his outward appearance was a well-rehearsed mask that covered a deepening depression. Regular viewers of Robert’s videos knew he lost his wife, as he shared a memorial video for her in April of 2024. What he was less open about with his viewers was his own health, which it turns out had been rapidly declining for the last few months.

We now know that simply getting up and walking around had become painful for Robert, a fact obscured by the fact that most of his videos saw him seated at his workbench or in the back garden. That he was able to continue making so many videos at all speaks not only to his passion for technology and engineering, but the great love he had for the community that he’d built.

From the video we also learned that Robert found it very difficult to discuss his declining mental and physical health with friends and family. For men of his generation, the “strong and silent type” was often the ideal. Given all that he was going through, nobody could fault him for experiencing a sense of hopelessness, and yet his brother explains that Robert would never admit to the difficulties he was facing. Whenever pushed to talk about his feelings, he’d respond with that phrase which we’ve all heard (and maybe used once or twice) — “I’m fine.”

Because of this, Robert’s family has partnered with the suicide prevention charity CALM (Campaign Against Living Miserably) to try and raise awareness about men’s mental health. They ask that anyone who wishes to honor Robert make a donation to CALM, in the hopes that they can help others who may find themselves in a similar situation.

It’s no great secret that many in the hacker and maker communities face their own daily struggles. Whether it’s from being neurodivergent, or the inability to fit in with mainstream society. Several of the staff here at Hackaday are from marginalized groups, and even among those who aren’t, let’s just say we have it on good authority that most of them didn’t get to sit with the “cool kids” back in high school. We also know that, just like Robert, many in the community find it difficult to communicate with others about how this impacts their mental health.

The lasting legacy of Robert Murray-Smith will of course be his incredible body of work, which will continue to inspire millions of viewers. But we can also honor him by making sure that we’re looking out for the well-being of friends, family, and even ourselves. There are resources available, and there’s no shame in asking for help when you need it.

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A Supercapacitor From Mushrooms

April 1, 2024 by 28 Comments

The supercapacitor is an extremely promising energy storage technology, and though they have yet to reach parity with the best batteries in terms of energy density, offers considerable promise for a future of safe and affordable energy storage. Perhaps best of all from our point of view, they are surprisingly simple to make. A practical supercapacitor can be made on the bench by almost anyone, as the ever-resourceful [Robert Murray-Smith] demonstrates using mushrooms as his feedstock.

The idea of a supercapacitor is to replace the flat plate on the simple capacitor from your physics textbook with one that has as large a surface area as possible for charge to accumulate on. In this case the surface is formed from organic charcoal, a substance which retains something of the microscopic structure of whatever it was made from. Mushrooms are a good feedstock, because their mycelium structure has a naturally huge surface area. He takes us in the video below the break through the process of carbonizing them, much easier when you have a handy kiln than trying the charcoal-burner method, and then grinds them to a powder before applying them as a paste with a binder to a piece of graphite foil. With two of these electrodes and a piece of paper towel as a dielectric, he demonstrates a simple benchtop supercapacitor running a small electric motor for a surprisingly longer time than we expected.

We’d like to see further work on home made supercapacitors, as we believe they have immense potential as well as storing the stuff. Meanwhile, this is by no means the most unexpected supercapacitor material we’ve seen.

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Airloom’s Whacky Wind Clothesline Turbine Idea

November 26, 2023 by 53 Comments

What if you don’t put airfoils on a central, spinning axis, but instead have them careen around a circular track? If you’re a company called Airloom, you’d say that it’s a very cheap, very efficient and highly desirable way to install wind-based generators that can do away with those unsightly and massive 100+ meter tall wind turbines, whether on- or offshore. Although grand claims are made, and venture capital firms have poured in some money, hard data is tough to find on their exact design, or the operating details of their one and only claimed kW-level prototype.

Transpower's 'flying clothesline' wind turbine setup.
Transpower’s ‘flying clothesline’ wind turbine setup.

Despite the claims made by Airloom, they’re not the first to have this idea, with Transpower in the 1980s making itself famous with their ‘flying clothesline’ that featured a continuous loop of sails tensioned between two ropes. These ran around a pole on either end with each having a generator for a claimed total of 200 kW. Ultimately Transpower seems to have gone under along with many other wind power pioneers of the era as they couldn’t make their idea economically feasible. Something which is a definite trend in the field.

Some parts about Airloom’s design are definitely concerning, with the available images showing each airfoil running along a central rail on a number of wheels and with their ‘Power Takeoff’ (i.e. generator) not defined in any meaningful manner. Here is where [Robert Murray-Smith] had a bit of fun in a recent video, creating his own dual-chain version that somewhat resembles a mixture between the Transpower and Airloom designs. He also put the design up on Thingiverse for others to 3D print and tinker with, requiring a handful of bearings for smooth running.

For the power takeoff, [Robert] suggests that in his design the cogs around which the chain moves could be attached to a generator (like in the Transpower design), but he could see no indication of how Airloom intends to do this. Feel free to put your own speculations in the comments. And if you’re from Airloom, show us the details!

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A Hobson’s Coupler Leads To A Weird Engine

August 10, 2023 by 19 Comments

You want to join two shafts. What do you need? A coupler, of course. If the shafts don’t line up, you might consider an Oldham coupler. But what if the shafts are at a 90-degree angle to each other? Then you need a Hobson’s coupler. [Robert Murray-Smith] has the 3D printed hookup for you and a video that you can see below.

The part isn’t all 3D printed, though. You do need some bearings and steel rods. [Robert] proposes using this to couple a windmill’s blades to a generator, although we assume some loss is involved compared to a standard shaft. However, we’ve heard that the coupler, also called a Hobson’s joint or a stirrup joint, is actually pretty efficient. However, you rarely see these in practice because most applications will use a gear train employing a bevel gear.

While it may not be practical, the second video below shows an elbow engine that would look undeniably cool on your desk. By making some changes, you can create a Cardan joint which happens to be half of what you think of as a universal joint. The Hobson coupler and the Cardan joint seem to be made for each other, as you’ll see in the video.

We aren’t sure what we want to make with all these mechanisms, but as [Robert] points out, with new materials and techniques, these mechanisms might have a role to play in future designs, even though they have been mostly discarded.

There are, of course, many kinds of couplings. Then again, not all useful joints have to move.

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3D Print Your Own Seiko-Style “Magic Lever” Energy Harvester

August 9, 2023 by 20 Comments

Back in 1956, Seiko created their “magic lever” as an integral part of self-winding mechanical watches, which were essentially mechanical energy harvesters. The magic lever is a type of ratcheting arrangement that ensures a main gear only ever advances in a single direction. [Robert Murray-Smith] goes into detail in this video (here’s a link cued up to 1:50 where he begins discussing the magic lever)

There is a lot of naturally-occuring reciprocal motion in our natural world. That is to say, there is plenty of back-and-forth and side-to-side, but not a lot of round-and-round. So, an effective mechanism for a self-winding watch needed a way to convert unpredictable reciprocal motion into a unidirectional rotary one. The magic lever was one way to do so, and it only has three main parts. [Robert] drew these up into 3D models, which he demonstrates in his video, embedded below.

The 3D models for Seiko’s magic lever are available here, and while it’s fun to play with, [Robert] wonders if it could be integrated into something else. We’ve certainly seen plenty of energy harvesting projects, and while they are mostly electrical, we’ve also seen ideas about how to harvest the energy from falling raindrops.

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A CVT For Every Application

July 1, 2023 by 36 Comments

When the subject of CVTs or continuously variable transmissions comes up, the chances are that most readers will think of the various motor vehicles they’ve appeared in. Whether it’s a DAF, a Ford, a FIAT, or a Chevrolet, most major manufacturers have tried one at some point or another with greater or lesser success. The automotive ones inevitably use a variation on a V-belt or metal band between variable separation conical pulleys, but this is by no means the only CVT configuration. Serial tinkerer [Robert Murray-Smith] takes an in-depth look at the subject as part of his ongoing fascination with wind turbines.

What caught our eye about this video isn’t so much the final 3D-printed design he selects for his experiments, but the history and his look at the different CVT designs which have appeared over the years. We see the V-belts, as well as the various cone configurations, the disk transmissions, the hydrostatic ones, and even magnetic versions. His transmission uses two cones with a rubber coating, with of all things a movable golf ball between them. We’re guessing it will appear somewhere in his future videos, so watch out for it.

Meanwhile, this isn’t the first time we’ve seen a CVT, [James Bruton] used a hemisphere to make one on a robot.

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Clay Makes For DIY Power Source, Just Add Water

June 15, 2023 by 16 Comments

[Robert Murray-Smith] starts out showing us some clay formations that house bees. He couldn’t take any of that clay home, but that’s no problem — clay is plentiful, and apparently, you can make a battery with it. Well, perhaps not really a battery. Adding water to zeolite — a clay often used as a filter material — generates heat, and where there’s heat, there can be electricity.

[Robert] uses a salvaged Peltier device, as you find in small electric refrigerators. These solid-state heat pumps usually convert electricity into a temperature differential, but in this case, it is used as a thermocouple, generating electricity from a temperature difference.

The clay used is a very fine aluminosilicate crystal known as zeolite 13X. Once it comes into contact with plain ordinary water, it immediately starts to boil. It’s a neat experiment, and with the Peltier underneath the metal container holding the clay, enough power is produced to spin a small motor. Of course this won’t power anything large, but on the other hand, plenty of things these days don’t take much power. This technique would work with any exothermic reaction of course, but there’s something compelling about the shelf-stability of water and clay.

Beats a potato, we suppose. Batteries don’t have to be difficult to make. It is only hard to make really good ones.

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