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5 votes
Accepted

Rotation around an axis outside of the mechanism

The design that you illustrated is pretty much correct. See below: In order for the end to move along a circular path, you want a four-bar-linkage with equal length arms. Note how the length of the ...
Jonathan R Swift's user avatar
4 votes
Accepted

How do folding barriers work?

What you see here is two sets of four-bar linkages connected to each other to form a six-bar linkage. To be more precise this is a Watt type 1 six-bar linkage. This particular configuration is known ...
joojaa's user avatar
  • 3,577
4 votes

Linkage of two shafts that need to rotate different angles

If you wanted to use circular gears you can use the following procedure. Assuming $i$ is the gear ratio, you'd need $$i = \frac{d_1}{d_2} = \frac{n_2}{n_1} = \frac{\theta_2}{\theta_1}$$ The distance ...
NMech's user avatar
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3 votes

Linkage of two shafts that need to rotate different angles

Figure 1. A CAD calculation for a direct linkage. You want the left wheel to turn 95° from 1 to 2. You want it to rotate the right wheel 83° from 3 to 4. The direct distance from 1 to 2 is 44.2 mm on ...
Transistor's user avatar
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3 votes
Accepted

Why is Scotch-Yoke mechanism not used for internal combustion reciprocating piston engines?

Making an engine using scotch-yoke mechanisms for all pistons on a multi-cylinder engine will increase the cost and add a lot of needless complexity and mass, especially rotating mass that won't ...
Solar Mike's user avatar
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3 votes

Transfer horizontal movement into vertical movement

Following up on the comment by @ForwardEd, I too believe the use of a pulley is benefitial to your problem, especially considering its excellent ability to change the direction of a force. In the ...
ToxicOwl's user avatar
  • 369
3 votes

what college level teaches mechanical linkage design?

It all depends on how complicated the linkage is. For many simple linkages all you need to know is trigonometry (sin, cos, tan) and torque/moment equilibrium (Force x Distance = Force x Distance). ...
ericnutsch's user avatar
  • 8,191
3 votes

Difference between Linkage, Kinematic chain, Mechanism, Mechanical element, Mechanical machine and their precise definitions

Here are some definitions for you, based on my experience with these terms: A linkage is a group of bodies (or links) connected together by joints. A kinematic chain is a subset of linkages, ...
BarbalatsDilemma's user avatar
3 votes

Rotation around an axis outside of the mechanism

This is a basic way of doing it. A rotating cam, attached to the triangle via a link through a bore in the reciprocating runner guide. The runner guide goes back an force in a path made by 4 bearings ...
kamran's user avatar
  • 22.5k
2 votes

Rotation around an axis outside of the mechanism

Another online resource you can try out is http://cadcam.eng.sunysb.edu/app/
NMech's user avatar
  • 24.4k
2 votes

Rotation around an axis outside of the mechanism

The program Solvespace may be of use to your project. The first example in a Solvespace video refers to the term 'mechanical linkage' and shows a circular path for one of the pivots of the linkage, ...
fred_dot_u's user avatar
  • 7,227
2 votes

what college level teaches mechanical linkage design?

There are some purely geometric linkage design methods, such as two and three position synthesis (which are easy enough to teach even a 8 year old). But there are methods that are not so geometrically ...
joojaa's user avatar
  • 3,577
2 votes

what college level teaches mechanical linkage design?

To answer your title, It's not really a matter of what college level, but rather what college. For example, a general studies college (one with a broad range of majors) may not offer such a class, ...
Jason's user avatar
  • 165
2 votes

Linkage of two shafts that need to rotate different angles

If you were to set up a gear mechanism, it would be two gears with circumference and radius ratio of 95/83, with the smaller gear at 95 switch. Therefore the same ratio links would rotate the switches ...
kamran's user avatar
  • 22.5k
2 votes

Transfer horizontal movement into vertical movement

No matter what you do, you will need a second body for your tree to move relative to. You could be using the earth as in your rope example. It is also possible to use a mass in the tree, much like a ...
Abel's user avatar
  • 1,352
2 votes

What would you call this mechanism and how can I calculate the forces involved

This is a type of ellipsograph or Trammel of Archimededs. It's a mechanism that is widely documented in textbooks for both the kinematics and the dynamics. Regarding the second part of your question, ...
NMech's user avatar
  • 24.4k
2 votes

3D linkage design - terminology

The easiest way to do this (either the direct or the inverse) is with the use of the homogeneous transformations. Basically, it is an augmented transformation matrix in 3 dimensions which can also ...
NMech's user avatar
  • 24.4k
1 vote

Rotating a series of lights such that each one rotates more than the previous one

Belt-driven pulleys seems easiest. Do an image search for "timing belts, pulleys and tensioners" and you should get some ideas.
Transistor's user avatar
  • 10.9k
1 vote
Accepted

How to calculate the mechanical advantage of torque reaction arms (or balanced articulated arms)?

In each joint, The moments are the weight of the load plus the weight of the lift arm(s) multiplied by the distance to the joint. setting the moments sum about the joint equal to zero will give ...
kamran's user avatar
  • 22.5k
1 vote

Planar linkage design based on output curve?

This is the classic point path linkage synthesis problem. Any kinematics textbook covers this topic. Design of Machinery - Robert Norton, Theory of Machines and Mechanisms - Uicker and Pennock, ...
prclinks's user avatar
1 vote

How to do linkage analysis for a two-arm lever?

The mechanism consists of four members, and can be modelled using three revolute joints at $A$, $B$ and $C$ and one prismatic joint at $D$. However, to get the ratio between stock force and handle ...
drC1Ron's user avatar
  • 423
1 vote

Transfer horizontal movement into vertical movement

P is a pivot, A and B are connected as shown. Movement in the horizontal plane via A is converted to movement in the vertical via B. There will be sinusoidal considerations if the movement is ...
fred_dot_u's user avatar
  • 7,227
1 vote

Is the DOF for a robot mechanism invariant if it is not in a different configuration?

yes, it would change. Say you have an arm that can both rotate and extend or retract. Say it has a joint articulation with a range of rotation about X, Y, Z axis and at the same time can elongate ...
kamran's user avatar
  • 22.5k
1 vote
Accepted

What is this bistate linkage?

I believe what you are seeing is a pendulum mounted on a sliding bracket. The weight with the thumbscrew indicates that it can be tuned to match the required movement to engage the V-shaped "socket" ...
fred_dot_u's user avatar
  • 7,227
1 vote

Why does this linkage calculate log?

Angles are related to trig functions, which are indeed related to exponentials, which in turn are related to logs. This means that logs and angles are distantly related (but in very interesting ways). ...
niels nielsen's user avatar
1 vote

Why does this linkage calculate log?

This is a classic linkage synthesis problem called "function generator". Before calculators, linkages like this were used to approximate mathematical functions. They died with the slide ...
prclinks's user avatar
1 vote

How do folding barriers work?

Think of the orange bar as the humerus bone in your upper arm, the blue bar as your radius, and the pink one as your ulna. The gate folds up in much the same way your arm folds up, and opens up much ...
Mara Gati Lucky's user avatar

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