• Fusion

Connecting joint motion

Connect the degrees of freedom of joints to simulate the mechanical behavior of the assembly.


Tutorial resources

These downloadable resources will be used to complete this tutorial:


00:03

In Fusion, once you link the joints in an assembly and apply motion ratios between joints,

00:09

you can create a motion study to test a machine assembly and simulate how the model operates.

00:14

The manual drill press shown initially has no relationship between the gears, so you need to create connections by linking the joints.

00:22

Expand the joints folder, and click the visibility icon to show the joints within the context of the assembly.

00:31

For this example, focus on the four gears, connect their joints, and include ratios.

00:37

Start by creating a motion link.

00:40

On the Design workspace toolbar, Assemble tab, expand Assemble and select Motion Link.

00:48

First, select the Main gear joint for the large, toothed gear, then select the Revolute 56 joint for the smaller gear.

00:57

Preview the motion and modify the angle value for the Revolute 56 Z rotation to 720 degrees to achieve the correct ratio.

01:07

Then, click OK.

01:09

Next, create another motion link between Revolute 56, the revolute joint on the smaller gear,

01:15

and Revolute 50 for the large, beveled gear.

01:19

Use an even ratio of 360 degrees in each Angle value, establishing a one-to-one relationship, and then click OK.

01:28

Now, if you rotate the large gear, you see the smaller and beveled gear rotating appropriately.

01:35

On the toolbar, in the Position group, click Revert to revert the position.

01:40

Finally, add the last motion link.

01:43

Select Revolute 50 for the large, beveled gear, and Revolute 67, at the top of the small bevel gear.

01:52

Set the Revolute 67 Angle value to 720 degrees, and then click OK.

01:58

Rotate the large gear, notice that the small bevel gear rotates incorrectly.

02:04

In the Browser, right-click the last Motion Link and select Edit Feature.

02:10

If the direction is incorrect, you can set the angle to a negative value, or click Reverse.

02:17

Then, click OK.

02:19

While the meshing may be slightly off, focus primarily on the motion.

02:24

Drag the large gear to verify that the direction is correct.

02:28

Once everything works as desired, Revert the position and review the overall design.

02:35

You can animate a joint to demonstrate the function of most mechanisms.

02:39

However, compound motions, such as the rotation of the drill chuck caused by turning the hand wheel,

02:45

and using the arm to lower the drill bit into the material, can be harder to explain.

02:51

To address this, click Assemble and select Motion Study.

02:56

A motion study enables you to select one or more joints and animate them through a range of motion.

03:02

Start by selecting the Main gear joint.

03:05

An initial value of 0 degrees is set at step 0.

03:09

In the Motion Study , select step 100, set the end Angle value to 720 degrees, and then press Enter.

03:20

This will create two revolutions.

03:22

Click Restart and Play to view the animation.

03:26

If it plays too fast or too slow, you can adjust the Speed slider and play it again.

03:32

You can also set the motion study Mode to Loop.

03:36

This plays the animation until you pause it, and then you can reset it to frame 0.

03:41

Next, click the Revolute 75 joint controlling the height of the drill bit, to add it to the Motion Study analysis.

03:50

Note that if the first joint is selected, you may need to click twice to add the new joint.

03:55

In the Joint list, deselect the Main gear joint to hide it in Motion Study, then select Revolute 75.

04:02

Select step 25 and accept the current angle value.

04:08

Next, select step 40 and enter a value of 5 degrees.

04:15

Then, select step 70.

04:19

If you select the wrong step, you can change the Step value and then press Enter to update it.

04:24

Then, select step 85 and enter a value of 30.4 degrees.

04:31

This will hold the same value until the end of the sequence.

04:35

Click Play, and you can verify the motion of the assembly.

04:40

Repeat the process to add additional joints, if needed, and play the sequence again.

04:45

For a machine assembly with compound motion, such as this drill press,

04:50

a motion study provides a more elaborate representation of how the model operates, compared to simply animating a joint.

04:57

Click OK to save your work, which adds a Motion Studies folder to the Browser.

05:03

You can return to this folder at any time to play or edit the motion study.

Video transcript

00:03

In Fusion, once you link the joints in an assembly and apply motion ratios between joints,

00:09

you can create a motion study to test a machine assembly and simulate how the model operates.

00:14

The manual drill press shown initially has no relationship between the gears, so you need to create connections by linking the joints.

00:22

Expand the joints folder, and click the visibility icon to show the joints within the context of the assembly.

00:31

For this example, focus on the four gears, connect their joints, and include ratios.

00:37

Start by creating a motion link.

00:40

On the Design workspace toolbar, Assemble tab, expand Assemble and select Motion Link.

00:48

First, select the Main gear joint for the large, toothed gear, then select the Revolute 56 joint for the smaller gear.

00:57

Preview the motion and modify the angle value for the Revolute 56 Z rotation to 720 degrees to achieve the correct ratio.

01:07

Then, click OK.

01:09

Next, create another motion link between Revolute 56, the revolute joint on the smaller gear,

01:15

and Revolute 50 for the large, beveled gear.

01:19

Use an even ratio of 360 degrees in each Angle value, establishing a one-to-one relationship, and then click OK.

01:28

Now, if you rotate the large gear, you see the smaller and beveled gear rotating appropriately.

01:35

On the toolbar, in the Position group, click Revert to revert the position.

01:40

Finally, add the last motion link.

01:43

Select Revolute 50 for the large, beveled gear, and Revolute 67, at the top of the small bevel gear.

01:52

Set the Revolute 67 Angle value to 720 degrees, and then click OK.

01:58

Rotate the large gear, notice that the small bevel gear rotates incorrectly.

02:04

In the Browser, right-click the last Motion Link and select Edit Feature.

02:10

If the direction is incorrect, you can set the angle to a negative value, or click Reverse.

02:17

Then, click OK.

02:19

While the meshing may be slightly off, focus primarily on the motion.

02:24

Drag the large gear to verify that the direction is correct.

02:28

Once everything works as desired, Revert the position and review the overall design.

02:35

You can animate a joint to demonstrate the function of most mechanisms.

02:39

However, compound motions, such as the rotation of the drill chuck caused by turning the hand wheel,

02:45

and using the arm to lower the drill bit into the material, can be harder to explain.

02:51

To address this, click Assemble and select Motion Study.

02:56

A motion study enables you to select one or more joints and animate them through a range of motion.

03:02

Start by selecting the Main gear joint.

03:05

An initial value of 0 degrees is set at step 0.

03:09

In the Motion Study , select step 100, set the end Angle value to 720 degrees, and then press Enter.

03:20

This will create two revolutions.

03:22

Click Restart and Play to view the animation.

03:26

If it plays too fast or too slow, you can adjust the Speed slider and play it again.

03:32

You can also set the motion study Mode to Loop.

03:36

This plays the animation until you pause it, and then you can reset it to frame 0.

03:41

Next, click the Revolute 75 joint controlling the height of the drill bit, to add it to the Motion Study analysis.

03:50

Note that if the first joint is selected, you may need to click twice to add the new joint.

03:55

In the Joint list, deselect the Main gear joint to hide it in Motion Study, then select Revolute 75.

04:02

Select step 25 and accept the current angle value.

04:08

Next, select step 40 and enter a value of 5 degrees.

04:15

Then, select step 70.

04:19

If you select the wrong step, you can change the Step value and then press Enter to update it.

04:24

Then, select step 85 and enter a value of 30.4 degrees.

04:31

This will hold the same value until the end of the sequence.

04:35

Click Play, and you can verify the motion of the assembly.

04:40

Repeat the process to add additional joints, if needed, and play the sequence again.

04:45

For a machine assembly with compound motion, such as this drill press,

04:50

a motion study provides a more elaborate representation of how the model operates, compared to simply animating a joint.

04:57

Click OK to save your work, which adds a Motion Studies folder to the Browser.

05:03

You can return to this folder at any time to play or edit the motion study.

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