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Tutorial on Assembly and SolidWorks Motion
Dept. of Mechanical Engineering 22.321 Mechanical Design I Written by: Gregg Merlino 9/22/2009 Revised by: Dimitri Soteropoulos 9/2/11
Objective:
This tutorial is an example of techniques used to create an assembly in SolidWorks and perform motion analysis.
Prerequisites:
This tutorial assumes the user has completed Tutorial 1: SolidWorks Modeling and Drawing with each part in the linkage completed.
Task 1: Creating the Assembly
Open all of your part drawings in SolidWorks, including pins and bearings. Pick one of the parts and begin an assembly from the part located in the file menu. In the assembly screen, you will notice a list of all your parts on the lefthand side of the screen similar to Figure 1. File>>make assembly from part
Figure 1. Begin Assembly Window
Click on the base plate, and drag it into the workspace. If additional parts are needed, click on insert components in the assembly tab at the top of the window. Insert>>Part 1
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Tutorial on Assembly and SolidWorks Motion
Once the parts have been added, they will float in space as seen in Figure 2.
Figure 2. Imported Parts in Solidworks Prior to Assembly
Relationships need to be established in order to create the linkage. The method of creating these relationships in SolidWorks is called mating. To illustrate, select the outer surface of a bearing and click on the Mate button in the toolbar (Figure 3). The parameters for the mate feature will open in the property manager on the left side. Next, select the surface on the inside of the base plate. Click the green check mark to accept the mate. The default mate created is concentric.
Figure 3. Example of Concentric Mate
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Tutorial on Assembly and SolidWorks Motion
Select the back of the base plate and the face of the bearing, and create a mate between them. The next mate will be coincident where the parts share the same plane. Repeat this process for each part until the assembly is made. The mates for each component of the link will be coincident and concentric. Remove any unused parts, and your final outcome will be a fully functional fourbar linkage with bearings and pins, similar to Figure 4.
Figure 4. Final Assembly after Mating
You can change the appearance of your links to obtain a better visual representation of your linkage. This change can be found in the edit drop down menu under appearance. Figure 5 illustrates changes made to the link appearance.
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Tutorial on Assembly and SolidWorks Motion
Figure 5. Linkage after Change of Appearance
Task 2: SolidWorks Motion Analysis:
After the assembly has been created, motion analysis can be performed. In the toolbar, click the drop down menu and select addins (Figure 6).
Figure 6. Addin Detail
Check the SolidWorks motion box, and click OK (Figure 7).
Figure 7. Addins Feature
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Tutorial on Assembly and SolidWorks Motion
After the motion analysis component has been added, a new option in the motion analysis drop down menu will appear. Select motion analysis. Figure 8 details options available in motion analysis.
Figure 8. Motion Analysis Interface
Next, select a motor using the motor icon in the motion analysis screen. Set the parameter for motor speed and direction as well as the desired part to set in motion. Figure 9 is a detail of the motor control Interface.
Select Rotary Motor for Linkage Select Face of Crank and direction Motor Speed Control
Figure 9. Motor Control Interface
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Tutorial on Assembly and SolidWorks Motion
Once the motor has been selected, the motion of the linkage must be calculated by clicking the motion study icon, found in the motion analysis screen (Figure 8). In order to plot displacement, each of the preceding steps must be performed. After motion study calculations have been made, the XY plot function can be used to calculate relative position. Open the XY plot window in motion analysis by
selecting the icon to begin plot sequence. Follow the selections shown in Figure 10 to plot the displacement of the couplers center of mass relative to the pin on the crank. The displacement plot is shown in Figure 11.
Point that you want to track Reference Point
Figure 10. Plot Parameters Window
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Tutorial on Assembly and SolidWorks Motion
Figure 11. Plot Display from Motion Analysis
The plot shown in Figure 11 was based on a sixsecond period determined by a motor speed of 10RPM. This value was not a default value. In order to plot one complete rotation of the crank, the period will need to be adjusted by dragging the time line bar to the desired time period. Figure 12 contains a detail of the time line bar at the bottom of the motion analysis window.
Drag line to adjust period of motion
Figure 12. Time Window
