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Extreme Reduction Gearing Device Offers an Amazing Gear Ratio
ErnieKey writes: The 3D printed extreme reduction gearing device, created by long-time puzzle maker M. Oskar van Deventer, may leave you puzzled for its obvious applications, but the coaxial cranking mechanism offers potential in a variety of real-world applications with multi-colored gears that move in opposite directions at a ratio of 11,373,076 : 1. This 3D printed reduction gearing device is compact and multi-colored, and looks deceivingly simple at first glance. Developed through a complex algorithm, it could possibly offer potential as parts for machines like 3D printers, aerospace and automotive components, as well as perhaps robotics and a variety of motors.
it could possibly offer potential as parts for machines like 3D printers, aerospace and automotive components, as well as perhaps robotics and a variety of motors.
Correct me if I'm wrong, but wouldn't that much reduction be fairly pointless? Wouldn't you basically have to make it out of unobtainium (the high-torque parts, anyway... most of it, that is) in order to do useful work with it?
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
It has a very specific meaning and the way it is used in this article is not it. Sorry, pet peeve.
TFA seems to conflate the ideas of speed ratio and force multiplication. That is only true if the mechanism is perfectly efficient. In practice some of the input force will instead be consumed opposing friction in the mechanism and the output force will be limited by the stretch of the parts. So the maximum force multiplication achived may be substantially lower than the speed ratio.
To make a high ratio gearbox practical for force multiplication the low torque high speed parts need to be small to minimise friction while the low speed high torque parts need to be large to prevent them from breaking.
To make it practical for accurate rotational positioning again the low speed parts need to be large, otherwise flexibility in those low speed parts will compromise the ability to accurately maintain position.
note: i'm known as plugwash most places but i screwd up registering that here somehow in the past and now can't register
Other than being printed, what's the special part? What makes it different from every other transmission other that it has many gears and uses excessive/bad ratios between them that make the device worthless from a practical perspective.
its got 5 tooth pinions FFS, that'd be so rough and wouldn't last any length of time under load ... And then he discovered that if repeatedly chain those gears you get larger ratios still.
You can do the same thing with fewer worm gears and smoother operation.
This isn't even a little bit new, he's just chained a bunch of gears and is using the inside of the circle rather than the outside.
Someone show this guy a traditional automatic transmission or a newer CVD and watch his head explode. His gadget is pretty trivial, certainly nothing novel about it
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In the end, a slightly less impressive variation on "Machine with Concrete."'?
I do not deploy Linux. Ever.
This is a fun device that can show you what can be done with 3D printed plastic. That said, it's useless. It would be really cool if I could apply 1 pound of force to the crank, turn it a Million times, and have it apply a Million pounds of rotational force at the other end. But it's made of plastic, so it won't do that. Indeed, the fast-rotating parts would wear out before the slow-rotating part made a single turn. So it's not even good as a kind of clock.
All that said, it's a good conversation piece, and probably worth the price for that.
Bruce Perens.
And you get Machine with Concrete by Arthur Ganson.
Tried to build this with my 3d printer. Something broke, and something seized, and to my amazement, it turned out to have 1:infinity gear reduction.
don't cut it off www.mgmbill.org
It reminds me of the harmonic drive - a low backlash, high ratio compact gear.
Other comments have noted that a very high ratio would need very strong matariels to transfer significant power.
That's true, but sometimes the point isn't power, the point is to move things over very small distances precisely.
> I'm not really all that well versed in electric motors but isn't the precision of an electric motor dependent on how precise the bursts of current are applied to it? I am assuming that any electric motor has a set minimal step it must take..
No, for tasks which require controlling the position or rate of rotation, the precision is NOt dependent on how precise the bursts of current are. You used the magic word there, "step". If you want to control the rotation of a motor with any precision, you use a type of motor called a stepper motor. You may be familiar with the commutator which regular hobby motors use to distribute current to different windings as the motor turns. By basically just removing the commutator, you end up with a motor that turns only 1/64th rotation with each pulse, and distributing those pulses to the different windings has yo be do
My browser submitted the post before I was done writing it.
Distributing those pulses to the different windings has to be done externally, via transistors or other controlling electronics. So the pulses don't need precision timing or anything, you just have to count them.
On the other hand, stepper motors can only have a certain number of steps per revolution (64 steps is a typical example, but other values are available) . So if you want something like 1/1000th turn, you do need a gear or screw of some sort.
For very slow rotation, such as clocks, synchronous motors are normally used. They use the ac swing from positive to negative rather than a commutator. They're quite accurate, and used to be more so, because the ac supply is regulated to exactly 60 hertz in order to allow power companies to interconnect. Again you don't have to deal with any intricate control of the pulses, just count the number of swings from positive to negative and back. The precision of the 60 hertz ac rate was recently reduced in the US, but it's still precise enough for most purposes.
The things that pass for nerdy today; this is like /. from the 1920's.