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Say you have a very complex completely mechanical machine, and you want to put a dial indicating rotation speed of the central drive shaft and its torque. But the machine is completely mechanical, and you don't have pneumatics or hydraulics in it. Is it possible to create a speed dial or a torque dial simply using springs and different types of gears? I would imagine an internal clock of sorts would be necessary for the speed dial, and that could be done. Any help would be much appreciated

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A centrifugal governor can show the RPM. And from that the torque.

Many snowmobiles and all-terrain vehicles, ATV use nongravitational spring-loaded governors to change the continuously variable transmissions (CVT).

. Wikipedia link. governor

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to read torque mechanically, you mount the engine or motor spinning the shaft on a hinge along one side and a compression spring along the other. when the engine is applying torque to the shaft, the hinge allows the motor to rock slightly, compressing the spring, and a needle attached to the motor will then read torque on a stationary scale next to it.

BTW note that an ordinary automobile speedometer contains gears and a rotating magnet near an aluminum disc. That magnet rotates via a flex shaft that runs to one of the front wheels of the vehicle. When the magnet rotates it applies a torque via eddy current induction to the disc in proportion to its speed. a small hairspring preloads the disc, to which the speedo needle is attached, so it reads zero when the magnet is not moving. it hence reads RPM without electronics or software.

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Interesting puzzle.

The speed dial could be something along the lines of the 'flying-ball governor' mechanism, with the travel of the sliding+rotating collar connected to another sliding non-rotating collar, and from there on to your dial, via linkage or cable.

A torque indicator seems harder, but perhaps by running the shaft power thru a differential, having one end 'fixed' via a torsion spring ?? I think the angular position of this end of the differential would then correspond to torque, per the stiffness of the torsion spring. You would be altering the stiffness of the connection, however.

You could also take the torque from the motor mount.

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