Child no longer required

I'll just leave this here.

Design a model in LDD using any of 95 brick types, send it to this "factory", and it makes it.

(Via, needless to say.)

Parallel to serial to ST-506 to 5-bit teletype to...

A reader writes:

This seemed right up your alley. I saw this on Gizmodo this morning:

Plug-adapter chain

I initially dismissed it as totally fake. After all, it's just a string of pin adapters, and you can't get a flash drive to talk to a parallel port.

But then I thought some more. What if one were to replace the crystal in the USB drive with one of a much lower frequency, and then write a virtual device driver which implements USB using the parallel port pins? This would, of course, make the USB device useless on a regular USB interface, but it seems like it would be possible. And there's also the question of "why on earth would you want to?", but if you're the type to ask that question, you probably wouldn't have seen it in the first place.

Do you have any insight as to why such an approach would or would not work technically?


Improbable assemblage

(Anyone can do it!)

This reminds me of the hardware dongle, one of the many wonderful creations of the copy-control industry. Nowadays I think copy-protection dongles are all USB, but there was a time when some lucky users had to daisy-chain multiple parallel-port doodads in order to run multiple protected apps at once.

As you say, there'd surely be some way to connect a USB thumb drive to a parallel port, but not with standard computer-store products. (No, you can't just take a USB-to-parallel adapter and turn it around.)

I'm sure this sort of trick has actually been done many times, to connect modern storage to legacy systems. I don't think it'd be a huge job for one of the modern easy-to-program microcontrollers (Arduino, etc). If you've got some 35-year-old industrial computer that still works fine except its moving-parts storage keeps crapping out when the mining dust or machine-shop shavings get into it, hacking up some way to replace its ancient hard (or floppy, or optical, or tape) drive with Flash RAM is attractive.

There's more than one part of the hack-as-presented that couldn't possibly work, but what I immediately noticed was the green USB-to-mini-DIN adapter, which is probably one of those standard adapters for connecting a USB mouse to a PS/2 port, several of which can usually be found in the desk drawers of anybody who's been using a PC for the last ten years.

Those mouse adapters are, as you say, just pin-adapters, containing no logic; you could in principle do the same job with paper-clips and tape. Mice that work with these distinctive green adapters all have USB and PS/2 compatibility built in, and use one or the other depending on what they reckons they're plugged into. I think any of the green adapters will work with any such mouse, but they won't work with a USB-only mouse, and they definitely won't work with USB devices in general.

This sort of thing is one of the standard causes of support people banging their heads on the desk.

Theorem: The guy who's daisy-chained adapters so he can plug his XT keyboard into his iPad is preferable to the guy who's managed to plug a PCI card into a memory slot by just pushing really, really hard.


Can you hack Methyltris(methylethylketoxime)silane?

I got my pack of Sugru silicone moulding putty today.

I haven't come up with anything to do with it yet (I'm trying to think of an application that needs both Sugru and polycaprolactone). But I like the packaging.

Sugru packet

To save you from going to the full-sized image on Flickr, there's a warning on the packet that "sugru® contains Methyltris(methylethylketoxime)silane; Gamma-Aminopropyl Triethoxysilane. May produce an allergic reaction".

If I was one of those people who're worried about unspecified "chemicals", I'd expect this stuff to cause complete skeletal eversion within three minutes of exposure.

Note also the blacked-out line on the package. Under the marker ink it says "Use within a year of purchase". Actually, Sugru's official shelf life is only six months. Which is a slight bummer, but I only bought one "Smart Hacks Super Pack", for £11 plus £1.26 postage to me here in Australia. So I'll probably be able to use it all before it dries up. You clearly shouldn't use the "buy a huge lifetime-supply sack for a volume discount" technique for Sugru, though.

The only thing I don't like about Sugru is the manufacturers' endless use of the word "hack". All sorts of unremarkable things are today being promoted to the status of hacks. Some of the things you can do with stuff that goes on like putty but turns into silicone rubber in 24 hours definitely qualify as hacks, but I don't think just putting a more comfortable grip on a knife, cable or nail clipper really counts.

(Several pictures in the Sugru gallery only use the stuff to put little rubber feet on some slippery object. This strikes me as a waste of this quite expensive product, since peel-and-stick self-adhesive rubber feet in all shapes and sizes are easy to find and very cheap. Sugru will probably stick better than your basic rubber foot, but since you can get more than fifty small rubber feet for about five US bucks, I think you'll have some spares.)

Here are all of the Sugru pictures on Flickr, including some neat ideas. Here's the photostream of "projectsugru / Jane ni Dhulchaointigh", which appears to be some sort of aberrant composite entity formed from the woman who invented Sugru, and the product itself. There's also a Flickr group called "Sugru Hacks" which only has six images in it so far. Perhaps I should start a "Sugru I-Refuse-To-Use-The-H-Word" group.

Apparently (PDF), methyltris(methylethylketoxime)silane is commonly used as a cross-linker in RTV silicone compositions. There are several related compounds used for the same purpose. Its MSDS (PDF) isn't very alarming.

Gamma-aminopropyl triethoxysilane, a.k.a. 3-aminopropyl triethoxysilane, seems (PDF) to be another common sealant/adhesive ingredient; it, again like several other silanes, can work as a cross-linker as well, and also as a "coupling agent" that helps polymers stick to surfaces. It seems to be (PDF) rather nastier than methyltris-blah-blah-blah. I presume Sugru contains little enough of it that most people won't suffer skin irritation. I may need to revise my plan to eat all of my Sugru, though.

(I found the above-linked PDFs on this chemical-company site.)

Before I looked this stuff up, I thought these two long-named chemicals might have been unique to Sugru. There has to be something unusual in Sugru, because it does seem to be a genuinely new product, not just some well-known industrial product being re-packaged at a huge markup for consumers, like Silly Putty or "mouse tape".

Whatever the secret herbs and spices are, though, they're not methyltris(methylethylketoxime)silane or gamma-aminopropyl triethoxysilane.

(Apparently Sugru is the first example of a "new class of silicone materials", the "Formerol" process for making which is patented. I can't find the patents, though.)

Today's mechanical conundrum

A reader writes:

As soon as I heard about "Steve Durnin's D-Drive, [possibly] the holy grail of infinitely variable transmissions", my BS meter activated and the needle swung to "Possible thermodynamics violation".

But in his favor he's got an actual physical prototype...

...and is attempting to have a metal model made so its input and output power can be tested.

What do you think of the concept, and can you tell how on earth it works? I'm still trying to figure out how this is too different from CVT, other than maybe a wider range.

I'm still wondering if this is somehow impossible, but personally I'm open to the possibility that it's a similar step such as CVT and the in-article claims are typical science-journalism overestimations.


Oh no - it's another New Inventors prize-winner!

Fortunately, though, an infinitely-variable transmission (IVT) is not actually in any way related to perpetual motion. All it is, is a continuously-variable transmission (CVT) that has some way to run its variable "gear ratio" all the way down to infinity-to-one, also known as a "driven neutral".

(This is, by the way, not the same as just running the gear ratio up so much, billions or trillions to one, that the final gear in the train is functionally immobile, and could be embedded in concrete without having any effect on the load of the driving motor for some years. A true "driven neutral" could be driven at a trillion RPM for eleventy frajillion years, and never turn the output at all. A transmission that bottoms out at zillion-to-one gearing would, however, be perfectly usable as a real-world infinitely-variable transmission.)

Because it can gear down to infinity-to-one, this does indeed mean that this transmission doesn't need a clutch, which does indeed reduce complexity. Whether a real-world version of the D-Drive would be too big or too heavy or inadequate in some other more complex way for real-world duty, though, I don't know. But there's nothing crackpot-y about the basic idea.

As the video makes clear, the big deal here is making an IVT - actually, a mere CVT, that still needed a clutch, would do - that uses standard gearbox-y sorts of components, or can in some other way handle lots of power and torque without being unmanageably big, expensive and/or quick to wear out.

Normal CVTs have been available in low-torque machinery like motor-scooters for some time, and are now showing up in some mainstream, full-sized cars as well. But they're still a fair distance from ideal.

It's easy to make a CVT, you see. Here's one made out of Lego. It's hard to make a CVT that can handle lots of power. And yes, the fact that most CVTs contain some sort of friction-drive device is a big part of the reason for this.

Note, however, that there's a big difference between dynamic-friction CVTs like this one or the Lego one, in which friction between moving parts transfers power, and static-friction CVTs like this one, in which friction locks components together (as in a clutch!), and they don't wear against each other.

But even here, real-world elements muddy the water and make it hard for someone who doesn't actually work at the engineering coalface to tell whether they're looking at something genuinely new and useful, or something that's not new at all, and/or won't work. Here, for instance, is the NuVinci transmission, a friction-based CVT that spreads the friction stress between numerous relatively lightly-clamped spheres - it's related to the "ball differential" with which R/C car racers are familiar. The NuVinci's makers claim it's useful for high-power, high-torque applications. And maybe they're right. I don't know.

For an excellent example of the ugliness that can happen when somewhat specialised knowledge is repurposed by people who, at best, don't know what they're talking about, look at this particular piece of "water-powered car" nonsense, where the well-known-to-jewelers electric oxyhydrogen torch is claimed to be some sort of incredible over-unity breakthrough. This sort of thing happens all the time - it's just, usually, not quite such a blatant scam.

As the Gizmag article mentions, many commercial CVTs are also deliberately hobbled by car manufacturers. They force the transmission to stick to only a few distinct ratios, and also to want to creep forward when at rest, just like a normal automatic transmission. This isn't a limitation of existing CVT technology, though; it's just deliberately bad implementations of it.

(The manufacturers do this so that people who're used to normal autos won't be freaked out by a CVT. Those of us who'd like the superior technology we pay for to be allowed to actually be superior just throw up our hands, and cross those cars off the worth-buying list.)

I think one trap for the D-Drive could be the second motor that handles the ratio-changing - that might need to spin really, really fast in certain circumstances.

There's also the fact that this is only really an infinitely-variable transmission at one end of the ratio scale. The D-Drive can gear down an infinite amount, and right on through zero to negative (reverse) ratios. But unless I'm missing something, I don't think it can gear up at all. So the output shaft can't ever turn faster than the input shaft. This is a problem if you want to do low-power flat-highway cruising, when the engine's turning quite slowly but the wheels are turning very fast.

Normal cars have significant gear reduction in the differential, though - the "final drive ratio". Perhaps if you make the diff a 1:1 device, which shouldn't make it that much bigger, the D-Drive's output-ratio limitation won't matter.

The reason why I'm saying "might" and "perhaps" so often is that I, like the New Inventors judges, am not actually an expert on the very large number of mechanisms that the human race has invented over the centuries. The simplicity of the D-Drive makes me particularly suspicious. The D-Drive's mode of operation may be a little difficult for people who don't work with mechanisms all day to intuitively grasp, but there aren't many components in there, and none of them are under 100 years old. Actually, that's probably a considerable understatement; I'm not sure when epicyclic gearing became common knowledge among cunning artificers, but I can't help but suspect that a master clockmaker in 1650 wouldn't find any of the D-Drive's components surprising.

Sometimes someone really does invent some quite simple mechanical device, like the D-Drive, that nobody thought of before. But overwhelmingly more often, modern inventors just accidentally re-invent something that was old when James Watt used it.

To get an idea of the diversity of mechanical movements and mechanisms, I suggest you check out one of several long-out-of-copyright books full of the darn things. I think Henry T Brown's 507 Mechanical Movements, Mechanisms and Devices is the most straightforward introduction; it's a slim volume available for free from here.

(If you'd like a paper edition, which I assure you makes excellent toilet reading, you can get the one I have for eight US bucks from Amazon. Here's a version of it for four dollars.)

And then there's Gardner Dexter Hiscox's Mechanical movements, powers, devices, and appliances, whose full title would take a couple more paragraphs, which is also available for free.

Both of those books carry publication dates in the early twentieth century, but many of the mechanisms in them were already very, very old. Like, "older than metalworking" old. But several of them are still, today, unknown to practically everybody who's not able to give an impromptu lecture about the complementary merits of the cycloidal and Harmonic drives.

(You may, by the way, notice rather a lot of mechanisms in those old books that do the work of a crank. That's because one James Pickard patented the crank in 1780 - plus ça change. This forced James Watt, and many other early-Age-Of-Steam engineers, to find variably practical Heath-Robinson alternatives to that most elegant of mechanisms to get the power of their pistons to bloody turn something. Watt's colleague William Murdoch came up with a kind of basic planetary gearing to replace the crank. Planetary gears have, in the intervening 230-odd years, found countless applications - including the D-Drive!)

Getting back to Mr Durnin and The New Inventors, they both currently allege that the D-Drive is a "completely new method of utilising the forces generated in a gearbox". According to this Metafilter commenter and this patent application, that may not actually be the case, since 18 of the 19 formal Claims made in the application appear to have been turned down. But, again, I could be getting this wrong, because somewhere behind the impenetrable thicket of legalese I suspect the "Written Opinion" may be saying that the final Claim actually is patentable as a separate worthwhile thing. (See also this forum thread.)

This all has me thinking, again, about the repeatedly-demonstrated gullibility of The New Inventors. When I can bring myself to watch the show, I keep thinking - OK, actually sometimes shouting - about how I'd spoil the party by asking at least one out of every four inventors "would you be willing to make a small wager that your device is not fundamentally worthless, or a duplicate of something that's been in production for years?"

(Sometimes, I'd just say "Have you always dreamed of being a rip-off artist, or is it a recent career development?")

The New Inventors seem to not have much of a peer-review system to keep the show free of crackpots, scammers and ignorant inventors who're unaware that their baby was independently invented in 1775. Or maybe there's just a shortage of interesting inventions, like unto Atomic magazine's shortage of interesting letters, so they let even the dodgy ones onto the show as long as they look impressive.

Perhaps the people on the judging panel just studiously avoid saying anything that might attract legal action from an inventor outraged that someone dared to point out that his magic spark plugs strongly resemble 87 previous magic spark plugs out of which the magic appeared to leak rather quickly.

Personally, I suspect that some insight into the newness or otherwise of the D-Drive may lurk in the various kinds of differential steering used in tanks. (Many of those have also been implemented, needless to say, in Lego.) And don't even ask about differential analysers.

It doesn't even take a lot of searching to find other IVTs. Here's one that, like the D-Drive, has no friction (or hydraulic) components. Its highest input-to-output gear ratio is quoted as "five to one", which is weirdly low; perhaps it's meant to be the other way around.

I hope, I really do hope, that the D-Drive turns out to be a proper new and useful device. We can always use another one of those.

But I remain very unconvinced that something this simple, aiming to do this straightforward a task, really is useful, let alone new.

UPDATE: As mentioned in the comments, Gizmag have a new post about this.

To summarise: The D-Drive does not remove all friction components from the drivetrain, because it can only ever be a part of that drivetrain, and needs supporting stuff that'll probably need friction components. And yes, it would need a motor just as powerful as the "main" one to drive the control shaft.

And Steve Durnin is apparently proud of independently coming up with a system similar to Toyota's Hybrid Synergy Drive "Power Split Device". I must be missing something, there, seeing as if this is the case then the D-Drive probably isn't patentable, and probably wouldn't even be particularly marketable.

"Sucking with both of those really didn't help..."

The brilliant Matthias Wandel, seeing how fast he can get his air engine to spin.

His wooden air engine.

(Just about everything Matthias makes, at least since the old stuff, is wooden. Wooden combination lock.
Wooden tank tracks. Wooden marble machines. Wooden Jenga pistol. Wooden pen centrifuge. Wooden pager rotator. Wooden gears. Wooden pipe organ. (Mostly) wooden bandsaw. Wooden binary logic. I don't think the Eyeballing Game and the gear template generator are made of wood, but I haven't examined his server. It could be all ropes and pulleys in there.)

I'm not certain that Matthias' video-based speed-estimation is completely sound. A proper tachometer would probably be a good idea.

There are, of course, a lot of ways to do that. Optical and magnetic sensors, point-and-shoot "non-contact" tachos made to do things like measure the rotational speed of machine tools and model-aeroplane propellers. And of course Lego, shop-bought or home-made (and with or without googly eyes).

Tachometry often involves multipliers or divisors of some sort; the above-linked Lego sensor tops out at only 500RPM, for instance, so you'd need to point it at something geared down from the thing you're actually measuring, to get a reading. And model-plane-prop tachos need to be told how many blades the prop has. For devices like this motor, which spins in the same range of speeds as computer fans, I wonder if you could use a computer fan to measure their speed?

Chop the blades off the rotor of a a standard three-wire computer fan, disable the motor coils (I think the speed sensor is a separate Hall-effect device), connect the de-bladed rotor to the thing whose rotational speed you want to measure, and then either use a frequency counter to measure the pulse rate on the yellow wire, or just plug the cable into a computer motherboard and run a fan-monitor utility.

Anybody tried it?

So many ways to be useless

Shannon's Ultimate Machine, aka the "Most Useless Machine", has become something of a fad.

So of course, people have made Lego versions.

I think this one, announced in this Lugnet post, is my favourite.

Yep - it's clockwork!

The clockwork motor it uses is either this one or this one. There's also this rather rare see-through one. You could probably also use one of the many pull-back motors.

(Bonus points go to anyone who makes a Useless Machine that's powered by the clock escapement from the #8888 Idea Book.)

Irresponsible Mayhem: The Saga Continues

This post from 2007 was about a highly entertaining YouTube clip of some people pulling arcs from a long string of nine-volt batteries. With those neat little clip connectors, 9V batteries are just begging to be clipped together into very long, very dangerous daisy-chains. And, in that particular case, they had 125 batteries in series, by my count. That adds up to a nominal 1125 volts DC.

(The 9V terminals are also, of course, clearly intended to make them easy to lick.)

But now, unfortunately, that video's been removed.

So I went hunting for more experiments of this type.

Here's a string of 19 (for 171 volts DC, nominal) running a compact fluorescent lamp:

The experimenter boldly holds the thin-insulation alligator-clip leads in his bare hands, but that's as exciting as this video gets. Interesting to see that these lamps run from DC as happily as from AC, though.

Here's some fun with 52 batteries:

That'd give 468V if the batteries were all at their nominal 9V, and could easily make it to 500V with fresh batteries. But apparently these were discarded "8.4... ish" cells of unknown provenance (my money would be on a company replacing the batteries in all of its smoke detectors). 52 times 8.4 gives a mere 437 volts, open-circuit.

(All of these voltages will plummet when you close the circuit, to start striking arcs, because the more current you ask for the further the terminal voltage will sag, and alkaline nine-volters aren't meant to deliver more than a very little current. Energizer, for instance, don't provide a maximum-current rating on the datasheet [PDF] for their standard alkaline nine-volters, but the maximum current on the load-versus-capacity graph is half an amp, at which discharge rate the capacity drops from a 25mA-load maximum of more than 600 milliamp-hours, to a little more than 300mAh. If you buy a Big Bag of Innocent Unsuspecting 9V Batteries the cheap way, by getting carbon-zinc "super heavy duty" batteries instead of alkalines, the rated current [PDF datasheet] is now only about 5mA, and the highest current on the performance graph is only 25 milliamps. You're not going to be able to pull a multi-amp arc out of a string of those poor little things for long. Ex-smoke-detector alkaline batteries will probably work a lot better for this sort of Unwise Experiment than will brand new carbon-zincs.)

Here we have 48 batteries in series - so, maybe more than 460 volts open circuit - molesting a coin:

(With, again, not as much attention paid to safety as might have been.)

Here, though, is what we've been looking for!

Four hundred and ninety 9V batteries, baby!

They're good for quite a lot of arcing before the chain's weaker links started breaking, too. I hope somebody was at least wearing a couple of pairs of sunglasses simultaneously.

490 times nine volts gives 4410V; fresh batteries would add up to more than 4700V. These are more ex-smoke-detector batteries, though; the video description says they only added up to "almost 4000V".

Even four thousand volts can't strike a very long arc by itself. The dielectric breakdown strength of dry air is about 33 kilovolts per centimetre (around 84 kilovots per inch). So four kilovolts, even with humid air helping it (and hindering electrostatic experiments...), can only strike an arc a few millimetres in length, at the very most.

Once you've struck a spark with the terminals close together, though, you can draw it out into a much longer arc, because the ionised air between the terminals - which may include vaporised matter from the terminals - is much more conductive than un-ionised air. That's how arc welding works (and Jacob's Ladders too, for that matter), and that's what's happening in the video clip.

If I ever do something like this, I think I'll leave the striking of arcs and burning of batteries for the grand finale, and do some low-current high-voltage stuff first.

Look upon my Lego gearbox, ye mighty, and despair!

OK, so you've got your Lego automatic transmissions, and they're pretty awesome. And there are a number of Lego continuously-variable transmissions, some of elegantly simple design, and those are impressive too.

And then somebody comes along and makes a seven-speed-plus-reverse sequential Lego gearbox, and puts it in a fully remote-controlled Lego Veyron.

With, of course, working steering, engine pistons, disc brakes...

Oh, and it's the targa-top version of the Veyron too, just to pack another darn mechanism in there.

Like someone whose unsettling dreams about becoming the world's greatest badass have been dissipated by an encounter with Raven, all of the rest of us are now under no pressure at all for high achievement in Lego engineering.

(The gearbox is only an expanded and improved version of the 8448 gearbox, mind you, so clearly this is not really that much of a big deal. Also, I think you'll find that Mount Rushmore isn't actually a very large mountain.)