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The older cars with an overdrive option also freewheeled when in overdrive.


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Well, the question has already been accepted, however. I'll mention something regardless. First of all, it's perfectly fine to use a plain threaded rod for linear motion. You mostly simply need to consider what your basic requirements are, and your willing budget. What I'm most surprised about, is that no-one here even considered to mention all the ways you ...


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An obvious solution is to design a "punch" that fits the groove, which you drive with a linear actuator. There are many ways to do that, a lead screw is an obvious one. you could use two small rounded grooves on the "punch" to fit the string (so that it doesn't get out and doesn't get squashed or mangled). Additionally I've put a small ...


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Mechanism you are looking for is something mechanical watchmakers have been searching for ages*. Because that is exactly what a mechanical wrirst watch does. The mechanism in question is called an escapement. Now the classical escapement moves in pulses, but there is a sub variant known as a constant force escapement that moves at constant speed if the force ...


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You can use regular threaded rod as a lead screw. The size and pitch (and grade) of the thread will determine your precision but 0.5 mm seems overkill for furniture positioning. The smaller the screw the finer the pitch and therefore precision will be, but at the cost of reduced load capacity. Just keep the rod lubricated and you shouldn't have issues.


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It's not exactly clear to me what you mean by trapezoidal thread rod. Like you noticed Metric threads are also trapezoidal (just like ACME with slightly difference face angels). Figure : Common types of bolts (source linearmotiontips) To my understanding (from the context of the question) the main differences that you are likely to find between the ...


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A very easy way is to attach it to a reducing gear, a gear with more teeth. You would choose the radius of the reducing gear like this. If your output is usually 10% above desired speed, we choose $$R_{final}=\frac{R_{initial}}{0.93}$$ Note we did not choose 0.90 because we want to hover near average desired output speed. By just choosing 0.93 we get close ...


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There are multiple things going on here. Your question indicates you have a variable input speed but want a constant output speed. The answer to this on its own would be a continuously variable transmission with a controller that sets the ratio according to the output speed. Any version that has a controllable ratio could be hooked to a simple pid ...


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To my understanding the Hartnell governor is a variation that might be applicable to your needs. Figure : HArtnell Governor source mechoholic Essentially it moves the sleeve against a compression spring (instead of gravity), so - at least in theory - you could turn it upside down.


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Not sure if this exists off the shelf, but what if you installed in line with the spinning gear a device with two weights held in place by springs, which would move outward if the centrifugal force became too high? I believe they also have devices that will declutch the engine if a speed is exceeded, but not sure that is a desired behavior. (https://i.stack....


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