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Questions tagged [pulleys]

96 questions
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Dynamics Simple Pulley System - Stuck on the Process

Have spent hours poring over this homework question but am having difficulty getting the right process going to solve the problem. I don't really know where to start, and I'd really be grateful if someone could show me the ropes (pun intended ^_^).…
Elisa Accordino
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What makes a pulley that is rated for horizontal pulling different from a pulley rated for lifting?

I have a home project that involves lifting a platform with a cable that runs through a series of pulleys to redirect the cable. I'm selecting pulleys for the job and I see that some pulleys are rated for horizontal pulling while others are rated…
Klik
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How to mount timing pulleys/belts for small DIY project

I'm building a rotating lamp for a small DIY project to learn about motors and timing belts/pulleys. As I am learning, finding parts that are small enough, fit a stepper motor shaft and reasonable priced is difficult. I am trying to find a way to…
jeremy
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comparing backlash of different mechanisms

I have a cylinder with a shaft in its center that I need to rotate at 120 RPM on 180°, for costing reasons, I would like, if possible, to reuse the same DC motor that I already use for another system. That motor has a speed of 6000 RPM so I need a…
LiohAu
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Is twisted belt configuration a good practice?

Internet is full of twisted belt examples (30, 60, 90 degrees), however, the allowed misalignment tolerances claimed by the manufacturers are less than several degrees. The very term misalignment seems to impose the two pulleys are out of single…
FlegmatoidZoid
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Degrees of Freedom for Complex Pulley Systems

I'm trying to understand DOF clearly, but this pulley system has me doubting myself. When I try to determine the degrees of freedom, I sum the DOF of each object, and subtract the constraints. for this system, I have four pulleys (1-4, in order of…
Mason Turvey
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How can I apply a load to an electric motor to simulate realistic conditions for an experiment?

I am trying to perform some experiments with a motor and I want to run it under realistic conditions (or at least not unloaded). Is there an easy way to load a motor? A couple ideas I had include: attach water paddles to paddle water continuously,…
Jacques
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How do you calculate the frictional losses in wire ropes over sheaves?

I am currently pulling a load with a wire rope that is moved through a system of sheaves, but had to replace a smaller wire rope cable (1/2") with a larger wire rope cable (3/4"). The sheave/wire diameter ratio is below the recommended guidelines,…
gsolorzanop
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choosing between v belt and round belt for fast RPM, low torque application

My pulleys are going to be rotated with a 1000-2000 RPM motor, with a constant RPM controlled by a hall effect sensor, there is going to be almost no torque as one of the pulleys just has a 100 gram optical element attached to it and all the pulleys…
Mark Legault
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Surprisingly Low Efficiency of Compound Machine [Project Help]

I'm working on a school project that requires us to build a compound machine with a mechanical advantage of 9. It should be able to lift a 10oz soup can three or more inches by using the weight of fifteen pennies. My machine consists of an inclined…
Mister_Maybe
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Mounting a timing pulley on a ball screw shaft

I have a pretty basic question. I need to install a timing pulley on a ball screw shaft (6mm): http://uk.rs-online.com/web/p/products/2816419/ The processed end (the pointy side) of the shaft is secured by a support mount, I need to place a timing…
JackS
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Difference between a "Pulley" and a "Wheel and axle"

A "Pulley" and a "Wheel and axle" seem much similar to each other. What is their actual difference and what are their precise definitions? My understanding of the two terms is much relied on the context of Simple machines. The wikipedia articles of…
Hamed Begloo
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Tower crane with a cabin on ground level

Pardon me for kind of a stupid question, but I keep wondering. Traditionally, tower cranes' cabins are located at the top of the tower. I can understand why it have been necessary up to ~1990s, when it was the only way for a human to get reliable…
GreyCat
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Bushed 3" V-belt pulley with unkeyed 3/4" shaft?

Shortly I will have two 3/4" unkeyed shafts needing 3" type-A V-belt pulleys, one each. They'll each have their own motor driving them, and will need to run to 5000 RPM and possibly higher in the future. Is anyone making pulleys for keyless…
Jonathan Brickman of Topeka KS
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How can you control the speed of a rope moving through a pulley?

I'm putting together a ceiling-mounted clothes rack. The rack is raised and lowered with rope and pulleys. If the rack is raised under full load and accidentally released, then the system could be damaged and it might pose a danger to anyone near…
Korgan Rivera
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