There are two silly-sounding musical instruments whose names I keep forgetting. With any luck, this post will fix them in my memory.
The first one makes a sort of tinkling "sproing" noise, and the second sounds like someone squeaking a cleaning cloth on a drinking glass, or window. They're both surprisingly common - considering how weird they sound by themselves - in Latin music.
This much information wasn't quite enough, however, for Google to lead me directly to the answers. (Not the first time, and not either of the later times when I forgot again, and looked them up again.) But I got there in the end.
The sproinger, frequently heard in the sort of 1970s cop-movie music that opens with frantic bongo drumming, is called a "Flexatone", or "Flex-a-tone" to give it its full original 1920s-patent trademarked name.
A "genuine" Flex-A-Tone will set you back at least $US26.99 (or $US34.50, for the deluxe version!). But this eBay seller (who's here on eBay.com.au) has, among a variety of other instruments that look absolutely ideal for giving to the small children of people whom you do not like, a "Flexitone" for only $US24.99 delivered within the USA, or $US33.99 including delivery to Australia.
Speaking as a man who already owns a siren whistle (not nearly as good as the expensive Acme version), a melodica and two Stylophones (the old analogue type, of course), I can't say I'm not tempted.
And then there's that rubbing-glass-sounding drum.
It's called a Cuíca, and it actually is played by squeaking a cloth on something. There's a stick inside the little drum, anchored to the middle of its single head. You rub the stick with a damp cloth to play the instrument, and alter pitch by pressing on the outside of the head with your other hand.
Here's a 4.6Mb video tutorial, which makes clear that certain jokes about the motions involved...
...are far, far too easy to be worth making.
The Cuíca is also known as a "laughing gourd" or "laughing drum" (not to be confused with the various kinds of talking drum). That's a fairly straightforward name, which made the Cuíca easier to look up than the Flexatone. Many other novelty instruments also have names deducible from their sound, like the humble "slide whistle", here demonstrated...
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.
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 archive.org 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 Pickardpatented 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.
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.
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.
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-effectdevice), 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.
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.
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.)
They're good for quite a lot of arcing before the chain's weaker links started breaking, too. I hope somebody was at leastwearing 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-voltagestufffirst.
Are you wondering, “Hey, in these belt-tightening times of international financial crises and slashed Internet advertising budgets, have thosecontextual-link-advertisingcompanies that splattered so many stupid irrelevant ad-links over so much of the Web cleaned up their act, and started linking from stuff that actually has something to do with what they’re advertising?”