SolidWorks Motion Study Tutorial

December 2, 2020
EngineeringClicks

There are three types of Motion Study: Animation/Basic Motion/Motion Analysis
Animation is the simplest, Basic Motion includes more information and Motion Analysis is the most complex
Assembly models can be found in the SOLIDWORKS software and can be used for sample tutorials
Animations are for mostly visual applications, for presentations etc.
Motion Analysis can be used to calculate various forces on assemblies and to generate plots for different parameters

SolidWorks Motion Studies allows for more complex machines like engines to be designed where every part is moving on the correct path. This SolidWorks Motion Study Tutorial will cover Animation and Motion Analysis.

CAD (Computer Aided Design) programs have always been able to transform an engineer or designer’s ideas into a real design through the creation of sketches and 3D models. These models could then be used for visual representations of designs for customers, or they could also be exported to CNC machines (and 3D printers more recently) for the creation of physical parts.

This has been the bread-and-butter for CAD programs since their inception and pretty much every software package has this capability. This applies to singular parts that are easily machined and assembled, but not to parts that have a dynamic relationship with each other and move in relation to one another on a certain path.This is where a feature like the SolidWorks Motion Studies can help. It allows for more complex machines like engines to be designed where every part is moving on the correct path.

The SolidWorks Motion System in particular can help the user in three main areas, where motion is needed, and the degree of difficulty:

Animation
Basic Motion
Motion Analysis

Animation in SolidWorks is classified as when the user would like a visual representation of movement in their design, for marketing purposes or a presentation, but not including any specific forces like gravity or mass. Motors can be added to drive the motion of the assembly and the position of parts can be set at pre-defined key points.

Basic Motion integrates an extra degree of difficulty into the design and adds the effects of springs, gravity, physical collision and mass. Basic Motion is still quite fast and will create an impressive, physics-based simulation. If your project requires this, the Basic Motion Study is for you.

Lastly, the most complex SolidWorks motion study level is Motion Analysis. This brings factors like damping, momentum, force and impact into the design. If you need this level of detail then a full Motion Analysis will be needed on your project.

For the purposes of this article, the SolidWorks Animation and SolidWorks Motion Analysis will be looked at in depth.

SolidWorks Animation

All SolidWorks motion studies start in the same way: an assembly is opened, the motion add-in is loaded (if needed), and the tab saying “Motion Study” must be clicked. Now the Motion Study Manager has been opened, the last step is to select the type of Motion Study that you will be conducting (Animation/Basic Motion/Motion Analysis) and begin!

There are many assembly models to be found in the program’s Resources>Tutorials folder, we will be using these tutorials to go through each of the motion studies. The plunger model is one of the simpler models, so we will utilize this for our Animation tutorial. You can locate the model in the: install_dir > samples > tutorial > motionstudies > animation folder.

You will want to start with defining a starting position. This will require you to go into the Motion Manager and position the time point at zero seconds. You can then move the camera around to its starting position, i.e. where you want the camera when the animation begins.

After you have positioned the camera, you need to select the parts that will be moving and how long the movement will last. For the plunger, it will be the orange arm to move up to a vertical position, perpendicular to the horizontal base.

The part labelled “arm left” must be found in the MotionManager, highlighted with a left click, and move the time bar out to five seconds. This determines how long the movement will last for. The “Add Key” button must then be selected to bring up a horizontal line from zero to five seconds on the “arm left” line. A diamond symbol known as a key point will be positioned at the end of the horizontal bar.

We have now selected the part that will be moving in the animation, and how long it will move for. Next the physical movement of the “arm left” shall be specified. This is quite simple, one must go to the design window where the assembly is located, select the orange arm and move it to the desired location. Once this is completed, we can click the “calculate” button over the MotionManager tree, and the assembly will begin to animate.

If it is desired that the component animation will end at the same point it started from, the user must select the diamond keypoint at five seconds, press CTRL+C, and move the keypoint to 2.5 seconds while keeping CTRL pressed. If done correctly, there will be a noticeable piece missing in the green changebar between 2.5 and 5 seconds, this is a pause in the animation.

Then the original keypoint at 0 seconds will have to be copied to 9 seconds on the timeline. This duplicates that start position and gives the animation the path to return to its original position at the end of the movement. The “calculate” button can now be pressed again, and the animation can be observed.

From here, now that the basic functions of the animation have been covered, it is at the users discretion how much customization and movement they would like in their animation. You can hide parts, make them see-through, change the appearance or texture among many other options. Rendering the animation is also an option to create a much more realistic looking part and environment.

GoEngineer have a video going through the animation workflow in a little more detail:

SolidWorks Motion Analysis

For this tutorial a cam and follower example, like those seen in automatic lathe machines, will be used. The contact forces between the parts in this assembly will be analysed as they progress throughout the motion. These results will then be plotted on a graph.

Motion Analysis is the most complicated form of motion study available in SolidWorks, and is far more complex than the simple animation seen in the last tutorial. This is a simulation of a real world situation, and features real forces and statistics.

This assembly model is located in the: install_dir > samples > tutorial > MotionStudies folder and it is called the Valve_Cam.

In MotionManager, select the tab that is labeled as “1200” and then click “Motion Analysis”, therefore determining your type of motion study. As the motion is already set up for this model, the “calculate” button can be clicked straight away and the movement of the parts can be observed.

Now we will start the analysis, the faces in contact that will be examined must be selected. Click “Isometric View” in the main window, and then select the “Results and Plots” button above the MotionManager. A “Results Property Manager” window will then appear, which includes multiple drop-down menus.

“Category”, the first menu box, will have an option for “Forces”, “Subcategory”, the second menu box, will include an option for “Contact Force”, and “Result Component”, the third menu box, has an option for “Magnitude.” The various options that are on offer within these menu boxes are the factors that determine the analysis type, so it is advised to be aware of them and somewhat familiar with the available choices.

Now that the three options for the analysis have been chosen, there is a final “Component Selection” option. Once selected, you must enter the design window and select both faces that will be examined. The faces we will be using are the surfaces in contact between the camshaft and the rocker.

The analysis is now completely set up, and the desired plots can be generated. Common plots include the reaction forces and displacement between the two surfaces. As can be seen in the video below, the reaction force gets bigger as the cam begins to lift up the follower. This is normal as there is now compression forces on the spring. The second peak comes as the spring is being relaxed as the rocker passes the cam. The video below will go through this process in detail:

Comparison Between Various Studies

So now that we have the results of the calculation, say we want to change some of the parameters on the motion study to see how that affects the graphs? Well, firstly go to the tab labeled “1200”, right-click, and select “Duplicate.”

Name the new tab as “2000” as the speed of the motor in the simulation will be upped to 2000 RPM, and the changes to the graphs will be seen.

The time bar can be dragged back to the start at zero seconds, and the component that is being changed, in this case the “RotaryMotor2” part can be selected. Right-click the part, and select the “Edit Feature” option. The motion can now be adjusted from 1200 RPM to 2000 RPM, and clicking the green tick confirms this change. The “Calculate” button must now be pressed again to re-analyse the motion with the new motor speed.

With this new simulation, a bouncing effect can be seen from the rocker hitting the cam after it has been lifted. A video showing this bouncing effect is shown here:

This bounce is a result of the faster rotation of the motor. The contact force is zero at the point when the rocker comes off of the cam, so we will need to adjust the spring constant to stop that from happening. An increase in the spring constant should ensure the motion is maintained.

To change this, find the part “LinearSpring2” in the components list in the MotionManager, right-click it and select the “Edit Feature” option.The properties of the spring should now be visible, the k value (spring constant) should be set to 0.1 N/mm, this can be increased to 10.00 N/mm. Again, select the green tick to confirm the changes and “Calculate”!

The bounce should now have been eliminated and the change can also be seen on the generated plots as there is more force on the spring that makes sure that the cam and rocker stay in constant contact at all times.

Conclusion

So there is a somewhat brief tutorial on how to conduct an Animation and Motion Analysis in SolidWorks. Once you are familiar with the functionalities and options that we have covered in this article, you should absolutely be able to go and conduct your own studies or animations with parts for your future projects!

As I am sure you are aware, the Basic Motion motion study was not covered in this post. This is because as it is a mix of an Animation and a Motion Analysis, covering all three methods would have resulted in a very repetitive tutorial! If you are comfortable conducting both the Animation and Motion Analysis studies, then a Basic Motion simulation should be no problem.

If you do run into any problems, remember that there is a world of information on YouTube covering all of these motion studies in great detail. A cool short clip of a Basic Motion study can be found linked below:

Both of the examples that we used in the tutorials can be found in the tutorial folder within the SolidWorks software. They are a great resource to be aware of and provide a decent foundation of knowledge when it comes to motion studies in particular. The SOLIDWORKS help website can also be referred to for more tutorials on any of the motion studies.

What we would recommend if you are a beginner is to try to follow these tutorials as best you can at first, and become familiar with the various options available within the different motion studies. Once you are comfortable with the examples and understand how everything works, you can then progress onto your own custom models and continue to enhance your skills in motion studies.

We hope that you have enjoyed these tutorials and if you would like to see more of these types of tutorials, please let us know what you would like to learn more about with a comment down below. Thanks for reading and we hope to see you back here again soon!