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Professional CAD/CAM tools built on Inventor and AutoCAD
Integrated BIM tools, including Revit, AutoCAD, and Civil 3D
Professional CAD/CAM tools built on Inventor and AutoCAD
Set joint limits, create motion links between joints, use contact sets, and analyze the movement of joints with motion studies.
Type:
Tutorial
Length:
9 min.
Transcript
00:03
Once joints are added to an assembly in Fusion,
00:06
there are a number of joint tools that can be used to study and refine the behavior of your design.
00:11
Implementing joint limits, motion links, contact sets, and motion studies can help you to create a more realistic and functional model.
00:20
This example has joints configured to create a vice on a hinge.
00:25
There is a slider joint for the sliding jaw to connect with the fixture;
00:29
a revolute joint, which enables a handle to rotate a screw through the sliding jaw;
00:33
and another revolute joint used as a hinge for the entire device.
00:37
When dragging these joints, notice that the motion of the model seems unrealistic.
00:43
For instance, the sliding jaw can move through the fixtures, and the handle does not cause the sliding jaw to move.
00:50
These issues can be resolved using a combination of joint tools.
00:55
In the Browser, expand the Joints folder and select the sliding joint.
01:00
Right-click the joint to access several options:
01:03
Drive Joints, Edit Joint, Edit Motion Limits, Lock Motion, Suppress, Animate Joint, and Animate Joint Relationships.
01:15
While Animate Joint focuses on an individual Joint, Animate Joint Relationships demonstrates how joints interact when animated together.
01:23
To address the issue of the slider going through the model, right-click the Slider joint and select Edit Motion Limits.
01:30
In the Edit Motion Limits dialog, you can set minimum and maximum values for the joint, as well as define a resting position, if needed.
01:39
Select the Minimum and Maximum options, then set the Minimum to -0.75 inches and the Maximum to 1.25 inches.
01:48
When you enable each limit, flags show on the canvas to indicate that they are active.
01:54
With these limits set, the jaws will stop at each end of the vice.
01:58
Be aware that joint limits only affect the specified joint and do not consider related components.
02:05
Setting up joint limits provides a realistic motion range, and you can configure them for any joint with available degrees of freedom.
02:13
Next, address the issue of the handle rotation not causing the sliding jaw to move.
02:19
On the toolbar, expand the Assemble menu, and select Motion Link.
02:25
If a notification asks whether you want to revert or capture the position, choose Revert to position.
02:32
Motion Link enables you to create a relationship between a revolute joint and a slider joint.
02:38
By linking these joints, you can establish a ratio of rotation to motion.
02:43
In the Motion Link dialog, verify that the Slider 42 and Revolute 16 joints are selected.
02:51
You will see the animation playing.
02:54
For Slider 42, set the motion to Slide Z and the distance to 0.394 inches.
03:01
For Revolute 16, set the motion to Rotate Z and the angle to 360 degrees.
03:08
So, for each complete rotation of the handle, the slider moves 0.394 inches in or out.
03:16
This setup simulates a gear ratio without relying on computationally heavy contact sets.
03:22
Click OK to save the link, and you will see it at the bottom of the Joints list.
03:27
Now, when you rotate the handle, the slider moves along with it.
03:32
You can see how these relationships begin to bring the motion to life.
03:36
However, the plates go through each other at the fully closed extent.
03:41
You can further refine the model using contact sets.
03:45
Click Assemble > Enable Contact Sets.
03:48
Then, in the Browser, right-click Contact Sets and select New Contact Set.
03:54
Select the two plates in the jaws, and then click OK.
03:58
Now, when these components meet, Fusion prevents them from passing through each other.
04:04
Note that contact sets are computationally intensive and may slow down your system, so they should be used judiciously.
04:11
For example, if you are working with gears,
04:14
attempting to create movement from the contact of those gears can quickly slow your computer as it tries to make the calculations needed.
04:21
However, a combination of contact sets and joint limits can provide both accuracy and efficiency.
04:28
By using a contact set, you can determine the maximum or minimum limit values.
04:34
In this case, you can determine the maximum position where two components make contact.
04:40
On the canvas, double-click the Slider value, and you see that the current offset value is 1.216 inches.
04:48
Press Esc to clear the selection.
04:51
Then, in the Browser, right-click Slider 42 and select Edit Motion Limits.
04:57
Set the Maximum value to 1.216 inches, then click OK.
05:02
Now, you can either delete the contact set or suppress it.
05:07
In this case, it is no longer needed, so you can delete it.
05:12
Now, when you slide the jaw back and forth, the plates contact each other but do not overlap.
05:18
Finally, explore the concept of motion studies.
05:22
To use a joint in a motion study, it needs to be unlocked.
05:26
Right-click the Revolute 2 joint and select Unlock Motion.
05:31
Then, to build the motion study, click Assemble > Motion Study.
05:36
When prompted, select the Revolute 2 joint.
05:40
Now, you can add steps and define joint values at each step to simulate motion over time.
05:46
In the Motion Study dialog, click to place a keyframe at time set 20.
05:51
Set the Angle to 45 degrees, and then press Enter.
05:56
The vise changes its angle.
05:59
While visualizing one joint is fine, motion studies enable you to analyze how multiple joints interact simultaneously.
06:07
To add a joint, on the canvas, select the Slider 42 joint.
06:12
Click at time step 30 to add a keyframe to the slider joint.
06:16
Set the distance to 0.2, press Enter, and the jaws open.
06:21
Scrub the time slider back and forth.
06:25
Now, you can see the jaws move along with the vice angle changing, providing a comprehensive view of the movement of your model.
06:32
Unlike Animate Joint, motion studies consider all related joints, offering deeper insights into the overall motion.
06:40
You can also control the playback speed and loop type for the study.
06:45
Once completed, click OK.
06:47
The motion study is saved in your Browser for future reference.
06:52
By implementing joint limits, motion links, contact sets, and motion studies, you can create a more realistic and functional model.
07:00
These tools enable you to study and refine the behavior of your design efficiently.
Video transcript
00:03
Once joints are added to an assembly in Fusion,
00:06
there are a number of joint tools that can be used to study and refine the behavior of your design.
00:11
Implementing joint limits, motion links, contact sets, and motion studies can help you to create a more realistic and functional model.
00:20
This example has joints configured to create a vice on a hinge.
00:25
There is a slider joint for the sliding jaw to connect with the fixture;
00:29
a revolute joint, which enables a handle to rotate a screw through the sliding jaw;
00:33
and another revolute joint used as a hinge for the entire device.
00:37
When dragging these joints, notice that the motion of the model seems unrealistic.
00:43
For instance, the sliding jaw can move through the fixtures, and the handle does not cause the sliding jaw to move.
00:50
These issues can be resolved using a combination of joint tools.
00:55
In the Browser, expand the Joints folder and select the sliding joint.
01:00
Right-click the joint to access several options:
01:03
Drive Joints, Edit Joint, Edit Motion Limits, Lock Motion, Suppress, Animate Joint, and Animate Joint Relationships.
01:15
While Animate Joint focuses on an individual Joint, Animate Joint Relationships demonstrates how joints interact when animated together.
01:23
To address the issue of the slider going through the model, right-click the Slider joint and select Edit Motion Limits.
01:30
In the Edit Motion Limits dialog, you can set minimum and maximum values for the joint, as well as define a resting position, if needed.
01:39
Select the Minimum and Maximum options, then set the Minimum to -0.75 inches and the Maximum to 1.25 inches.
01:48
When you enable each limit, flags show on the canvas to indicate that they are active.
01:54
With these limits set, the jaws will stop at each end of the vice.
01:58
Be aware that joint limits only affect the specified joint and do not consider related components.
02:05
Setting up joint limits provides a realistic motion range, and you can configure them for any joint with available degrees of freedom.
02:13
Next, address the issue of the handle rotation not causing the sliding jaw to move.
02:19
On the toolbar, expand the Assemble menu, and select Motion Link.
02:25
If a notification asks whether you want to revert or capture the position, choose Revert to position.
02:32
Motion Link enables you to create a relationship between a revolute joint and a slider joint.
02:38
By linking these joints, you can establish a ratio of rotation to motion.
02:43
In the Motion Link dialog, verify that the Slider 42 and Revolute 16 joints are selected.
02:51
You will see the animation playing.
02:54
For Slider 42, set the motion to Slide Z and the distance to 0.394 inches.
03:01
For Revolute 16, set the motion to Rotate Z and the angle to 360 degrees.
03:08
So, for each complete rotation of the handle, the slider moves 0.394 inches in or out.
03:16
This setup simulates a gear ratio without relying on computationally heavy contact sets.
03:22
Click OK to save the link, and you will see it at the bottom of the Joints list.
03:27
Now, when you rotate the handle, the slider moves along with it.
03:32
You can see how these relationships begin to bring the motion to life.
03:36
However, the plates go through each other at the fully closed extent.
03:41
You can further refine the model using contact sets.
03:45
Click Assemble > Enable Contact Sets.
03:48
Then, in the Browser, right-click Contact Sets and select New Contact Set.
03:54
Select the two plates in the jaws, and then click OK.
03:58
Now, when these components meet, Fusion prevents them from passing through each other.
04:04
Note that contact sets are computationally intensive and may slow down your system, so they should be used judiciously.
04:11
For example, if you are working with gears,
04:14
attempting to create movement from the contact of those gears can quickly slow your computer as it tries to make the calculations needed.
04:21
However, a combination of contact sets and joint limits can provide both accuracy and efficiency.
04:28
By using a contact set, you can determine the maximum or minimum limit values.
04:34
In this case, you can determine the maximum position where two components make contact.
04:40
On the canvas, double-click the Slider value, and you see that the current offset value is 1.216 inches.
04:48
Press Esc to clear the selection.
04:51
Then, in the Browser, right-click Slider 42 and select Edit Motion Limits.
04:57
Set the Maximum value to 1.216 inches, then click OK.
05:02
Now, you can either delete the contact set or suppress it.
05:07
In this case, it is no longer needed, so you can delete it.
05:12
Now, when you slide the jaw back and forth, the plates contact each other but do not overlap.
05:18
Finally, explore the concept of motion studies.
05:22
To use a joint in a motion study, it needs to be unlocked.
05:26
Right-click the Revolute 2 joint and select Unlock Motion.
05:31
Then, to build the motion study, click Assemble > Motion Study.
05:36
When prompted, select the Revolute 2 joint.
05:40
Now, you can add steps and define joint values at each step to simulate motion over time.
05:46
In the Motion Study dialog, click to place a keyframe at time set 20.
05:51
Set the Angle to 45 degrees, and then press Enter.
05:56
The vise changes its angle.
05:59
While visualizing one joint is fine, motion studies enable you to analyze how multiple joints interact simultaneously.
06:07
To add a joint, on the canvas, select the Slider 42 joint.
06:12
Click at time step 30 to add a keyframe to the slider joint.
06:16
Set the distance to 0.2, press Enter, and the jaws open.
06:21
Scrub the time slider back and forth.
06:25
Now, you can see the jaws move along with the vice angle changing, providing a comprehensive view of the movement of your model.
06:32
Unlike Animate Joint, motion studies consider all related joints, offering deeper insights into the overall motion.
06:40
You can also control the playback speed and loop type for the study.
06:45
Once completed, click OK.
06:47
The motion study is saved in your Browser for future reference.
06:52
By implementing joint limits, motion links, contact sets, and motion studies, you can create a more realistic and functional model.
07:00
These tools enable you to study and refine the behavior of your design efficiently.
Once joints are added to an assembly in Fusion, implementing joint limits, motion links, contact sets, and motion studies can help to create a more realistic and functional model.
The design in this example has joints configured to create a vise on a hinge:
When dragging these joints, the sliding jaw can pass through the fixtures, and the handle does not cause the sliding jaw to move. These issues can be resolved using a combination of joint tools.
Use the Edit Joint Limits tool to limit the sliding jaw movement:
Flags show on the canvas to indicate that the limits are active.
Note that joint limits only affect the specified joint and do not consider related components.
For the assembly to work properly, turning the handle must move the sliding jaw of the vise. Create this relationship by adding a motion link between the revolute joint and the slider joint. Linking these joints enables a ratio of rotation-to-motion to be established.
An automatic animation shows the handle and sliding jaw moving together.
For each complete rotation of the handle, the slider will move 0.394 inches in or out. This setup simulates a gear ratio without relying on computationally heavy contact sets.
Because the maximum limit previously set for the slider joint was approximate, the jaw plates pass through each other at the fully closed extent. Use a contact set to make the maximum limit precise.
The movable jaw now slides until the two jaw plates make contact; then it stops.
Contact sets are computationally intensive and may slow down your system. In this example, the contact set created previously can be used to determine the exact maximum distance for the jaw slider. Then, after using this value to edit the slider joint limits, the contact set can be removed.
The contact set can now be deleted or suppressed.
Finally, explore the concept of motion studies.
To use a joint in a motion study, first, it needs to be unlocked.
To build the motion study:
Now, steps can be added and joint values defined at each step to simulate motion over time.
Motion studies also enable the analysis of multiple joints interacting simultaneously:
The motion study is saved in the Browser for future reference. Unlike using the Animate Joint tool, motion studies consider all related joints, offering deeper insights into the overall motion.
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