Modelling a four bar mechanism in SolidWorks

A Mechanism in any mechanical system is used to either transform or transmit some given input motion. The best demonstration of a mechanism is that used in an engine.

In this particular mechanism the input motion from the crank is transmitted to the slider. There are two ways of looking at this in that the motion whilst being transmitted is also transformed from one of being rotation to linear motion.
 
I will model a simple four bar mechanism in SolidWorks to show how the links move relative to each other. Four bar mechanisms form an integral part of mechanical systems.
 
Let’s begin by creating the four links making up the mechanism.
 
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Once we are done creating the links, we can proceed to create a new assembly.
 
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We can then insert the links in the assembly one by one. After this, we can go ahead and define the mates for the parts.
 
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The final assembly should look like the one above.
 
Remember to fix the frame (longest link). You can check to see whether the mechanism is a Grashof linkage by rotating the crank and see if it rotates 360 degrees.
 

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You can then create an animation of the study to really visualize how the links move relative to each other.
 
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Remember that to run a motion study you must first ensure that the SolidWorks motion add-in in the add-ins folder is active.
 
Begin by defining the driving link and its rotation speed.
 
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You can even create a motion plot to show movement of the joints. Right click on any link and choose to create a motion plot.
 
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You can choose any joint you would want to trace its path.
 
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Finally you can record you animation if you wish.
 

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