Questions tagged [linkage]

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.

A mechanical linkage is a 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.

This tag could be used for questions asking about the design or use of various mechanisms as described.

The simplest possible linkage is a four bar mechanism, because a triangle is fully defined. Another simple mechanism is the crank mechanism that can be thought of as a special case of the four bar.

A four bar mechanism

Image 1: A simplified schematic of a four bar mechanism. Links A-B, B-C, C-D and the ground connection form four bars. The circles represent rotational joints.

41 questions
8
votes
3 answers

What method can I use to make a pivot point in an aluminum linkage?

I recently had a project where I made an aluminum linkage (similar to a scissor lift) operated by linear actuators. Aluminum pieces were fabricated from 6061 "standard" aluminum stock, 6mm (0.25 inch) thick. The bars are at most 750x75mm (30x3").…
JYelton
  • 183
  • 1
  • 8
7
votes
2 answers

Design of a Four-Bar Infinity Coupler Linkage

How can I control a Four-Bar Infinity Coupler such that it does not accidentally become a Paralellogram Linkage? It seems to me that, when the bars are all horizontal, gravity could change the movement of the green driven…
skibulk
  • 419
  • 3
  • 10
5
votes
4 answers

Rotation around an axis outside of the mechanism

I want to design a system of linkages that will allow me to rotate the green element around the blue point/axis without entering the red circle. The green triangle to go fully around the blue point. I only need about 120 degrees. I have seen…
Allshar
  • 85
  • 4
5
votes
2 answers

Applications of Five-Bar Mechanisms

I have some university work to do based on a real world application with five or six bar mechanism, but I am unable to find such a device. Are there real applications of such mechanisms? I've considered some, such as the trigger of a gun and a…
4
votes
3 answers

Linkage of two shafts that need to rotate different angles

I have two switches that have different throw angles the switches have shafts coming out of them which are connected the the cams that can be seen in the attached pic. One needs to rotate 95 degrees to throw and the other 83 degrees to throw, the…
Cooper
  • 41
  • 1
4
votes
1 answer

GIM Mechanism Software (Kinematics / Analysis / Synthesis)

I've recently discovered a very awesome software tool for the synthesis and analysis of mechanisms. The tool is called GIM, from Faculty of Engineering in Bilbao, Department of Mechanical Engineering, University of the Basque Country (UPV/EHU) …
zipzit
  • 281
  • 1
  • 2
  • 9
4
votes
0 answers

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 I've reproduced in fusion 360 and I'm trying to…
4
votes
3 answers

what college level teaches mechanical linkage design?

I'm 17 years old and learning first-year college math. What college level math do I need for mechanical linkage design? Can I learn designing and creating mechanical linkage without math but with my geometric intuition? or there's resource I can…
Hunhwi Kim
  • 41
  • 1
3
votes
1 answer

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

So I have an assembly with two pins sliding in two groves. First I would like to know if there's a name for this so I can do some more research. Second, if the assembly is standing up so that the top pin travels vertically and the bottom…
user34065
  • 31
  • 1
3
votes
3 answers

How do folding barriers work?

With folding barriers like the one below, how does the orange bar get turned by the green mechanism? What's inside the yellow triangular part? https://www.youtube.com/watch?v=LF8kSTCZIxw
John M.
  • 1,033
  • 8
  • 12
2
votes
2 answers

Lengths of Connectors in Steering Linkage

Below is a picture 4-wheel vehicle steering linkage. I figured that in order to steer correctly $(W+D)tan\theta_1=Dtan\theta_2$ where $\theta_1$ is the angle of the outside front wheel, $\theta_2$ is the angle of the inside front wheel, $W$ is the…
IOWF
  • 21
  • 3
2
votes
3 answers

Transfer horizontal movement into vertical movement

I would like to transfer horizontal swaying movement of a tree into oscillating vertical movement. How to do it? It does not have to be ideal perpendicularity or straightness. More or less efficient mechanism. Update. More details on measures. I…
2
votes
1 answer

What is this bistate linkage?

I've found this video on YouTube: https://youtu.be/hWK8Gv0JHqk?t=220 Watch from 3:40 to 4:20. I'd like to learn more about this linkage that makes that link alternate between hitting and missing the sliding link. I've searched for the animated…
GuiRitter
  • 123
  • 3
2
votes
0 answers

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 meet each other (this looks like a big rib cage,…
DeltaG
  • 123
  • 2
1
vote
1 answer

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 angle of the driven "rocker"? I've tried to work the function…
T.S
  • 113
  • 3
1
2 3