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2

One option that has no parts that wear out is eddy current brake. It consists of a metal disc, and a magnet in close proximity to it. The magnetic field will cause eddy currents in the metal disc, which in turn cause a torque that opposes the rotation. The energy is converted into heat in the wheel, which can be cooled down by either air flow or with liquid ...

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One way is to have a tensioning roller where the cable is held in contact or loops round it once. Looping round « locks » the cable to the roller - much like the positioning capstans used to move ships. Then the roller’s speed can be controlled by a variable hydraulic pump to keep the correct tension . This way the friction, heat and adjustment can be ...

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Assume point "P" is rigid, calculate the fluid pressures on both sides of the wall, from the respective free water surface down to point "P", then sum the moments about it. I assume you know how to calculate the resultant forces, and the locations of their application (1/3 height of the respective pressure diagram above the base).

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I believe I need to set my limits of integration so that point P is zero and then my torque will be P(z)*z --> (integral from 0 to -z+depth of P) P(z)zdz I can do that for both sides and add the torques

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An automatic transmission and its convertor adjusted to output of proper torque, seems a good choice combined with a solenoid switch. The output can easily be adjusted by a digital switch board.

6

In the wire & cable business, the device you describe is called a dancer, for the way its components move about while regulating the tension in a rope or wire being unspooled from a large coil. The simplest examples use a rim brake which drags against the flange on the big spool. The rim brake is on a lever arm and the end of the arm is attached to a ...

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Seen in a cinematic production years ago is a spooling system which used a series of paddles arranged on an axle. As the cable and human was pulled downward by gravity, the paddles spun in a manner similar to a fan. Drag increases by speed squared with a bit of a fudge factor, but it's sufficient to say that as the force of gravity accelerates the downward-...

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Assume the cable is simply looped around the pulley in counter-clock-wise direction, the initial position should be as shown on the sketch (by the side of pulley). Further assume the pulley and the motor are fixed in space, and the platform is attached to another end of the cable. Then the tension in the cable equals mass of the platform times gravitational ...

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This is a quick answer till further detail by the OP. The 10 kg forces directed downward at the ends of the bars cancel out as for the rotation of the system, they just impart 40kg force at the axel. Let's say the length of the bars is 100cm. and we ignore the axel for now because it is too close to the rotation center. Then the moment of inertia of each ...

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let me take a stab at this. Similar to linear motion of a mass m on a frictionless surface or in space, that a force $F$ no matter how small will move a mass no matter how big, albeit with smaller acceleration if the mass is bigger or F smaller. $$F=m\alpha$$ A torque no matter how small will turn a disk or a randomly shaped piece of rock or an ice skater ...

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In your case it is the inertia that you have to calculate with. A quantity related to inertia is rotational inertia (→ moment of inertia) See Wikipedia for more info.https://en.wikipedia.org/wiki/Inertia

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You need to be concerned with other factors that impact the system as soon is it passes the transient time it accelerates from $\omega=0 \to \omega_{final}$ Those are friction, air drag, vibration, etc. Going back to your question, We are going to ignore the contribution of the cylinder both because of its mass and it's being almost at the center of ...

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