A mechanical linkage is an system of connected bodies. The connections are called joints, that come in many flavors. Linkages allow you to design various path movements, speed profiles and force changes. The simplest possible linkage is a four bar mechanism and its special case the crank mechanism.

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How to calculate the coupler length in a crank rocker mechanism

I'm trying to learn a bit about building kinematic mechanisms by building a small project. The goal is to be able to open and close a box programmatically via a servo motor. I have a small box that ...
34 views

Gear design for symmetrical opening of two parts

I'm trying to build a lamp which has about 20 identical layers stacked on top of each other. There is a central spine and, on each level, a pair of arcs attached to the spine that are hinged and which ...
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1 vote
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*** modified design with new gas spring approach -I couldn't find shoulder bushing with large enough shoulder diameter so I will buy nylon tubing and cut them to lenght (Item 11) and add abs washer I ...
1 vote
764 views

Is there a formula that relates the two angles in a crank rocker?

I'm working on a mechanism that requires a crank rocker - is there a formula that relates the angle (to some fixed reference; horizontal, vertical, whatever) of the driving "crank" to the ...
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1 vote
217 views

Six-bar linkage is shown on the image: It has one degree of freedom, so if one of the variables is constrained, it's possible to calculate the positions of all the joints. In this specific case the ...
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1 vote
402 views

Synthesis of 5 bar mechanism

I'm working on my university project but I can't find a proper synthesis method for 5 bar mechanism. I'm working on underactuated mechanism. It's a slider crank with the connecting rod divided into 2 ...
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Free body diagram problem: Linkage w/ magnets and friction hinge

I am a bit stumped on a IRL problem, which i simplified in the diagram below: There are left and right beams (gray) linked together by a friction hinge. The bottom beam (black) is connected to the ...
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I am too dumb to make Peaucellier–Lipkin linkage work

I tried in math.stackexchange.com and they send me here. First: Don't crucify me for not "doing math", or asking a dumb question. School was a long time ago, and lose what you don't use. My ...
25 views

I'm trying to design a space-saving, wall-mounted, fold-away workbench that has an auxiliary platform that folds out. The fold-away linkage to support the aux platform when it's folded out is taxing ...
40 views

Mechanical Rotation about a Virtual Axis for Robot EOAT

I am working on a robotics application where we are erecting a cardboard box and stapling the ends shut. I need control over the "top" end flap to make sure it is out of the way for the rest ...
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"Snapping" shut/quickly closing gates

Suppose you have a set of two gates like so: Where you only want one of the gates to be in the "open" (non-blocking") position at any given time, this being the other possible state: ...
50 views

Number of degrees of freedom of parallel mechanism

Can anyone provide me with the number of degrees of freedom (translational and/or rotational) at point P? Edit with my assumptions: The left picture shows the mechanism from the side and the right ...
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What is the correct term for a joint stabilized by three points of articulation?

I am trying to find the correct term for this mechanical principle. I have a biomechanical system where two objects are anchored to each other along three points of articulation. These points are ...
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I am unsure how I would solve this. I have tried to solve it and got -29.1 but my attempt was wrong. Could someone please lead me in the right direction or show me the way to solve this? Thank you.
214 views

What is the effect of caster angle in automobiles? What will happen if we use neutral caster?

What is the effect of caster angle in automobiles and what will happen if we use neutral caster? We study that positive caster makes vehicle more stable at high speeds. It increases lean while ...
121 views

Linkage between two vertically and horizontally offset wheels

I'm trying to drive a wheel with a radius of 20cm that is 20cm above the motor and horizontally offset by 20cm from the motor, similar to the following: I wonder what a good linkage might be for a ...
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3k views

Toggle position of a fourbar slider-crank

In the fourbar mechanism as in the following picture, I have to find the toggle position, the sliding distance and the time ratio. Here is my understanding/plan to do this: The toggle positions ("...
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I am facing a difficult question and can't find answers anywhere else. What on the left is a hydraulic ram, it's pushing the box in the centre to move upward, while the four-bar linkage attached on ...
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Is there a spherical joint equivalent to a 4 bar linkage?

In a 4-bar linkage, all the joints are regarded as hinge joints. However, when I searched "spherical 4-bar linkage system", I didn't get a 4-bar system with spherical joints but instead a 4 bar system ...
136 views

What is the correct mathematical approach to this linkage problem?

I have a linear actuator with 52 millimeters of travel. I have a set of linkages with specific dimensions as shown in the images below, to which this actuator will be attached. The REF dimension is ...
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