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In Fusion, you can use joints without switching workspaces to position components and assign motion behaviors in your assemblies. Then, with motion studies, you can explore and evaluate movement in your assembly.
Type:
Tutorial
Length:
11 min.
Transcript
00:03
If you are transitioning from SolidWorks or a similar CAD software,
00:07
then you are most likely accustomed to adding several mates to fully constrain and create just one effective joint.
00:14
Fusion does things a little bit differently.
00:18
When a joint is added, it limits all degrees of freedom.
00:22
Then, you simply select the respective kinematic joint to define the required motion.
00:27
There are several types of joints available in Fusion.
00:31
This Joint Types model was designed to highlight how each one works, noting the movement or lack thereof.
00:38
First, the Rigid joint locks two components together, limiting all degrees of freedom.
00:44
In other words, there is no movement between either component.
00:48
Revolute uses a rotational motion around one joint origin.
00:54
The Slider joint allows you to make a translational movement along a specified single axis.
01:01
Cylindrical is a combination of Revolute and Slider where you have one translational and one rotational movement along the same axis.
01:11
Pin Slot is like cylindrical, though the rotational movement is not constrained to the same translational axis.
01:19
Planar utilizes two translational and one rotational movement on a single axis.
01:26
And lastly, the Ball joint gives you full rotational movement in all three axes for each joint.
01:33
You can also amend the maximum and minimum values of the respective planar or revolute axes.
01:39
This allows you to align your assembly, giving you complete control over your joints and their motion.
01:45
For example, when the maximum and minimum values are edited for the Revolute and Slider joint limits,
01:51
you can see how the joint movement is different from before.
01:56
When working with joints, it is important to understand the Capture Position command and as-built joints versus grounding.
02:04
The Capture Position command, as the name implies,
02:07
captures the repositioning of a component in time after it has been moved in any axis,
02:12
which can be useful when you need to evaluate and remedy interferences for position-dependent assemblies.
02:18
Capture Position is recorded in the Timeline and can be edited or suppressed.
02:24
This means that any capture positions are not permanent and can be easily reverted.
02:29
In this example, cut-outs are needed on this Geneva wheel to allow the driver, which is the pin, to slide in and out.
02:37
Some joints are already in place, but it needs to be rotated to get into position.
02:42
To do this manually, in the Toolbar, Modify panel, select Move/Copy, and then select the wheel.
02:51
Turn it to -30 degrees.
02:54
Then, from the toolbar, click Capture Position.
02:58
Next, click Move/Copy again, make sure Components is selected, and select the drive wheel.
03:06
Rotate it by 90°, select Capture Position, and click OK.
03:13
Now the pin is in the correct position, and you can see both commands captured in the timeline.
03:19
Right-click the second one.
03:21
From here, you can revert this position back to the original by suppressing the command, or by moving it back in the timeline.
03:29
At this point, the cut-out can be created based on the positions and pattern for this Geneva wheel,
03:34
and the assembly and motion can be finished.
03:37
Again, realize that when you use Capture Position, it appears in your timeline and can be edited at any time.
03:44
Next, it is important to understand the difference between the Ground command and As-Built joints in Fusion.
03:51
When working with subassemblies in SolidWorks,
03:54
you would typically find yourself fixing a component, then building the remaining components around it.
04:00
Fusion works differently, although it achieves the same result.
04:05
In this example, two subassemblies have been created using the Geneva wheel design, but with some subtle differences.
04:12
In the first, you can see that the base plate has been grounded,
04:16
which means the component's origin is locked to the origin of the top-level design.
04:21
Therefore, the base plate cannot be moved, yet the mechanism can be moved using contact sets and joints.
04:29
The second example instead uses an As-Built Rigid joint, which locks the geometry of a component to another component,
04:36
or to the top-level design origin, as in this case.
04:40
Again, the base plate cannot move, yet the mechanism still functions.
04:45
Which of these methods you use depends on how these subassemblies are brought into a much larger assembly.
04:52
Here, copies of the Grounded and As-Built Rigid types have been inserted into a new assembly.
04:58
An As-Built Rigid joint is created for each by pressing Shift+J for each top-level design.
05:04
Again, this locks the component's origin to the origin of the top-level design.
05:10
Now, try to drag the As-Built joint assembly, and you can see that the base plate is still unable to move,
05:16
and again, with the contact sets in place, the mechanism still functions as intended.
05:22
However, the entire grounded assembly is free to move in space, and the mechanism cannot be rotated.
05:29
The reason for this is, the ground command references the subassembly top-level design origin, which is now changed.
05:36
The reference has been lost, and you can see that there is now no red pin next to the base plate.
05:43
With the as-built joint example, the geometry is referenced and has not changed, so therefore, the references have been maintained.
05:51
The Ground command can be useful if you need to quickly test a feature,
05:55
or for saving computer resources when working with multiple joints.
05:59
So, as a best practice, you should use the as-built joint, particularly with subassemblies.
06:05
With those practices in mind, a more realistic example is this engine.
06:10
An as-built joint needs to be placed between the engine casing and the master assembly, before adding any kinematic joints.
06:18
The piston only needs to move in one translational movement along a single axis in the engine block,
06:24
so a Slider joint is best to replicate that movement.
06:27
Select the joint origins that appear on the component, and then apply a Slider joint.
06:35
Next, to add the rotational movement, a Revolute joint is added between the crankshaft and the engine block,
06:42
and another is used for the connecting rod and connecting rod journal.
06:47
One quick tip here is to hold the Control or Command key to lock in the joint origin to a face or feature as you hover the cursor over it.
06:56
This makes it easier to select those that are difficult to reach or out of view.
07:01
Finally, the piston pin needs to always be central to the piston.
07:06
In this case, you can use the Between Two Faces command, then right-click and select the respective faces.
07:14
And again, press Control or Command to constrain the respective face or feature before setting this joint to Rigid.
07:22
In other CAD software, you may have found yourself creating planes to generate these same movements,
07:28
yet in Fusion, you can achieve this in a few clicks.
07:32
So now, once the model is animated, you can see the joints working together.
07:37
Due to the top-down modelling approach in Fusion, components are modeled in place based on existing component geometry.
07:45
Consequently, it is best to use an As-Built joint because you select the components rather than the geometry origins.
07:52
Then you define the joint type.
07:55
This process allows you to quickly add components based on their design joints.
08:00
After you create joints in a model, you will need to refine them to accurately represent their real-world movement.
08:07
In this robot arm model, for example, you can define the joints limits for each movement of the arm and claw.
08:14
Right-click a joint and select Edit Joint Limits.
08:18
This process is similar in SolidWorks when you set the start, minimum, and maximum values.
08:24
You do the same here in Fusion, and then when you drag the component, you can see the defined joint limits in action.
08:31
Alternatively, and for more accurate results here in Fusion,
08:35
you can utilize contact sets to establish joint limits by moving a selected component until it collides with another selected component.
08:44
First, expand the Assemble drop-down and select Enable Contact Sets.
08:49
Then in the Browser, right-click Contact sets and select New contact set.
08:56
Then select the two grippers on the robot arm.
08:59
Click OK.
09:01
Now drag one of the grippers towards the other gripper, and you will see it stop when it comes in contact.
09:07
This indicates that the absolute limit has been reached before an interference occurred.
09:13
To see that value, double-click the joint glyph.
09:16
Now, you can assign that value to the joint limit.
09:20
Right-click the Slider joint and select Edit Joint Limit.
09:24
Select Minimum and Maximum and then enter the value.
09:29
Click OK.
09:31
Then in the Browser, suppress the contact sets.
09:35
In the model, drag the gripper, which now stops at the point of contact.
09:40
Lastly, as in SolidWorks, you can perform a motion study in Fusion.
09:45
Motion studies let you analyze the movement and rotation between joints,
09:50
which helps you understand how your product and its components will interact with each other in real life.
09:56
To create a motion study, expand the Assemble drop-down and select Motion Study to open the Motion Study panel.
10:04
In the model, click the joint you want to review, and make sure the visibility is on in the Browser.
10:10
In the Motion Study panel, you can set the time or step at which a rotational movement occurs for the respective joint's degree of freedom
10:18
and to what value.
10:19
To fully understand how the components move in relation to each other,
10:24
at the bottom, you can select the Mode to make it go in one direction, bidirectional, or repeated.
10:31
You can also set the speed.
10:33
Repeat this process for any other remaining joints, and you now have your finished motion study.
10:39
Use the play controls to play it forwards or backwards.
Video transcript
00:03
If you are transitioning from SolidWorks or a similar CAD software,
00:07
then you are most likely accustomed to adding several mates to fully constrain and create just one effective joint.
00:14
Fusion does things a little bit differently.
00:18
When a joint is added, it limits all degrees of freedom.
00:22
Then, you simply select the respective kinematic joint to define the required motion.
00:27
There are several types of joints available in Fusion.
00:31
This Joint Types model was designed to highlight how each one works, noting the movement or lack thereof.
00:38
First, the Rigid joint locks two components together, limiting all degrees of freedom.
00:44
In other words, there is no movement between either component.
00:48
Revolute uses a rotational motion around one joint origin.
00:54
The Slider joint allows you to make a translational movement along a specified single axis.
01:01
Cylindrical is a combination of Revolute and Slider where you have one translational and one rotational movement along the same axis.
01:11
Pin Slot is like cylindrical, though the rotational movement is not constrained to the same translational axis.
01:19
Planar utilizes two translational and one rotational movement on a single axis.
01:26
And lastly, the Ball joint gives you full rotational movement in all three axes for each joint.
01:33
You can also amend the maximum and minimum values of the respective planar or revolute axes.
01:39
This allows you to align your assembly, giving you complete control over your joints and their motion.
01:45
For example, when the maximum and minimum values are edited for the Revolute and Slider joint limits,
01:51
you can see how the joint movement is different from before.
01:56
When working with joints, it is important to understand the Capture Position command and as-built joints versus grounding.
02:04
The Capture Position command, as the name implies,
02:07
captures the repositioning of a component in time after it has been moved in any axis,
02:12
which can be useful when you need to evaluate and remedy interferences for position-dependent assemblies.
02:18
Capture Position is recorded in the Timeline and can be edited or suppressed.
02:24
This means that any capture positions are not permanent and can be easily reverted.
02:29
In this example, cut-outs are needed on this Geneva wheel to allow the driver, which is the pin, to slide in and out.
02:37
Some joints are already in place, but it needs to be rotated to get into position.
02:42
To do this manually, in the Toolbar, Modify panel, select Move/Copy, and then select the wheel.
02:51
Turn it to -30 degrees.
02:54
Then, from the toolbar, click Capture Position.
02:58
Next, click Move/Copy again, make sure Components is selected, and select the drive wheel.
03:06
Rotate it by 90°, select Capture Position, and click OK.
03:13
Now the pin is in the correct position, and you can see both commands captured in the timeline.
03:19
Right-click the second one.
03:21
From here, you can revert this position back to the original by suppressing the command, or by moving it back in the timeline.
03:29
At this point, the cut-out can be created based on the positions and pattern for this Geneva wheel,
03:34
and the assembly and motion can be finished.
03:37
Again, realize that when you use Capture Position, it appears in your timeline and can be edited at any time.
03:44
Next, it is important to understand the difference between the Ground command and As-Built joints in Fusion.
03:51
When working with subassemblies in SolidWorks,
03:54
you would typically find yourself fixing a component, then building the remaining components around it.
04:00
Fusion works differently, although it achieves the same result.
04:05
In this example, two subassemblies have been created using the Geneva wheel design, but with some subtle differences.
04:12
In the first, you can see that the base plate has been grounded,
04:16
which means the component's origin is locked to the origin of the top-level design.
04:21
Therefore, the base plate cannot be moved, yet the mechanism can be moved using contact sets and joints.
04:29
The second example instead uses an As-Built Rigid joint, which locks the geometry of a component to another component,
04:36
or to the top-level design origin, as in this case.
04:40
Again, the base plate cannot move, yet the mechanism still functions.
04:45
Which of these methods you use depends on how these subassemblies are brought into a much larger assembly.
04:52
Here, copies of the Grounded and As-Built Rigid types have been inserted into a new assembly.
04:58
An As-Built Rigid joint is created for each by pressing Shift+J for each top-level design.
05:04
Again, this locks the component's origin to the origin of the top-level design.
05:10
Now, try to drag the As-Built joint assembly, and you can see that the base plate is still unable to move,
05:16
and again, with the contact sets in place, the mechanism still functions as intended.
05:22
However, the entire grounded assembly is free to move in space, and the mechanism cannot be rotated.
05:29
The reason for this is, the ground command references the subassembly top-level design origin, which is now changed.
05:36
The reference has been lost, and you can see that there is now no red pin next to the base plate.
05:43
With the as-built joint example, the geometry is referenced and has not changed, so therefore, the references have been maintained.
05:51
The Ground command can be useful if you need to quickly test a feature,
05:55
or for saving computer resources when working with multiple joints.
05:59
So, as a best practice, you should use the as-built joint, particularly with subassemblies.
06:05
With those practices in mind, a more realistic example is this engine.
06:10
An as-built joint needs to be placed between the engine casing and the master assembly, before adding any kinematic joints.
06:18
The piston only needs to move in one translational movement along a single axis in the engine block,
06:24
so a Slider joint is best to replicate that movement.
06:27
Select the joint origins that appear on the component, and then apply a Slider joint.
06:35
Next, to add the rotational movement, a Revolute joint is added between the crankshaft and the engine block,
06:42
and another is used for the connecting rod and connecting rod journal.
06:47
One quick tip here is to hold the Control or Command key to lock in the joint origin to a face or feature as you hover the cursor over it.
06:56
This makes it easier to select those that are difficult to reach or out of view.
07:01
Finally, the piston pin needs to always be central to the piston.
07:06
In this case, you can use the Between Two Faces command, then right-click and select the respective faces.
07:14
And again, press Control or Command to constrain the respective face or feature before setting this joint to Rigid.
07:22
In other CAD software, you may have found yourself creating planes to generate these same movements,
07:28
yet in Fusion, you can achieve this in a few clicks.
07:32
So now, once the model is animated, you can see the joints working together.
07:37
Due to the top-down modelling approach in Fusion, components are modeled in place based on existing component geometry.
07:45
Consequently, it is best to use an As-Built joint because you select the components rather than the geometry origins.
07:52
Then you define the joint type.
07:55
This process allows you to quickly add components based on their design joints.
08:00
After you create joints in a model, you will need to refine them to accurately represent their real-world movement.
08:07
In this robot arm model, for example, you can define the joints limits for each movement of the arm and claw.
08:14
Right-click a joint and select Edit Joint Limits.
08:18
This process is similar in SolidWorks when you set the start, minimum, and maximum values.
08:24
You do the same here in Fusion, and then when you drag the component, you can see the defined joint limits in action.
08:31
Alternatively, and for more accurate results here in Fusion,
08:35
you can utilize contact sets to establish joint limits by moving a selected component until it collides with another selected component.
08:44
First, expand the Assemble drop-down and select Enable Contact Sets.
08:49
Then in the Browser, right-click Contact sets and select New contact set.
08:56
Then select the two grippers on the robot arm.
08:59
Click OK.
09:01
Now drag one of the grippers towards the other gripper, and you will see it stop when it comes in contact.
09:07
This indicates that the absolute limit has been reached before an interference occurred.
09:13
To see that value, double-click the joint glyph.
09:16
Now, you can assign that value to the joint limit.
09:20
Right-click the Slider joint and select Edit Joint Limit.
09:24
Select Minimum and Maximum and then enter the value.
09:29
Click OK.
09:31
Then in the Browser, suppress the contact sets.
09:35
In the model, drag the gripper, which now stops at the point of contact.
09:40
Lastly, as in SolidWorks, you can perform a motion study in Fusion.
09:45
Motion studies let you analyze the movement and rotation between joints,
09:50
which helps you understand how your product and its components will interact with each other in real life.
09:56
To create a motion study, expand the Assemble drop-down and select Motion Study to open the Motion Study panel.
10:04
In the model, click the joint you want to review, and make sure the visibility is on in the Browser.
10:10
In the Motion Study panel, you can set the time or step at which a rotational movement occurs for the respective joint's degree of freedom
10:18
and to what value.
10:19
To fully understand how the components move in relation to each other,
10:24
at the bottom, you can select the Mode to make it go in one direction, bidirectional, or repeated.
10:31
You can also set the speed.
10:33
Repeat this process for any other remaining joints, and you now have your finished motion study.
10:39
Use the play controls to play it forwards or backwards.
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