How can the degrees of freedom of a mechanism be obtained?

AI Thread Summary
The discussion focuses on calculating the degrees of freedom (DoF) for a can crusher mechanism using the formula M=3(n-1)-2j1-j2. The user substitutes values, concluding that M equals 2, but believes the DoF should be 1. Participants emphasize the importance of defining terms like mobility, number of links, and joints for clarity. There is a request for a clearer drawing of the can crusher to better understand the calculations. Overall, the consensus is that the mechanism likely has 1 DoF, pending clarification of the visual representation.
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Summary: ##M=3\left(n-1\right)-2j_1-j_2##

Hi, I'm trying to get the degrees of freedom of a can crusher.

1654270512452.png

So substituting I get

##
\begin{array}{l}M=3\left(n-1\right)-2j_1-j_2\\
n=5\\
j_1=5\\
M=3\left(5-1\right)-2\cdot 5-0\\
M=2\end{array}
##

And I would think it would be 1
 
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Welcome to PF.

It's best to define all of your terms when posting equations. Assuming that this is a standard DoF problem, I think:

M = Mobility
n = Number of Links
j = Number of Joints

Is that correct? Also, did you generate the drawing of the can crusher on the right? If so, could you somehow show what corresponds to what on the picture on the left? I'm having trouble seeing how you came up with it.

I agree that I think this crusher "hinge" has basically 1 DoF, but it would be best to understand your drawing first to be sure. Thanks.

https://en.wikipedia.org/wiki/Degrees_of_freedom_(mechanics)
 
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berkeman said:
Bienvenido a PF .

Es mejor definir todos sus términos al publicar ecuaciones. Suponiendo que este es un problema estándar de DoF, creo:

M = movilidad
n = Número de enlaces
j = Número de articulaciones

Es eso correcto? Además, generó el dibujo de la trituradora de la lata a la derecha? Si es así, ¿podría mostrar de alguna manera qué corresponde a qué en la imagen de la izquierda?? Tengo problemas para ver cómo se te ocurrió.

Estoy de acuerdo en que creo que esta "bisagras" de la trituradora tiene básicamente 1 DoF, pero sería mejor entender su dibujo primero para estar seguro. Gracias.

https://en.wikipedia.org/wiki/Degrees_of_freedom_(mecánica)
Hi Berkeman, I changed the image and did it above but it doesn't seem to be correct

Imagen6.png


The original image was this
Imagen8.jpg
 
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