Use the Motors tool to apply a motor to a hole, surface, or pin.
Motors drive parts in a rotational manner, and can be defined in terms of angle, speed,
acceleration, or torque. Inputs can be based on time or another variable in the model (state
dependent variable).
Location: Motion ribbon, Forces group
Click the
satellite icon that appears when you hover over the Motors tool to view a list of all motors in
your model.
Add/Edit Motors
A motor is defined by a shaft and a base. The first click positions the shaft, and
the second positions the base.
Select the Motors tool.
Select a hole, surface, or pin.
For holes and surfaces, click once to position the shaft, and a second
time to position the base. (You can select the same hole or surface
twice, in which case the second click is interpreted as reacting against
ground.)
For pins, click once to replace the pin with a motor.
In the microdialog, select an input:
Time Dependent: Make the motor dependent on time.
State Dependent: Make the actuator dependent on the state
of a variable object (joint, motor, actuator, spring-damper, system, or
measure). You can then represent input relationships such as Torque vs.
Speed, Force vs. Angle, or Force vs. Distance. For details, see State Dependent Inputs.
Optional: Use the θ, ω,
α, T drop-down menu to change
the type of motor. Options are speed, angle, acceleration, and torque.
Optional: Use the +/- button to reverse the motor's direction of
rotation.
Enter a magnitude in the text field for the rotation speed, angle,
acceleration, or torque. Think of this as a target speed or angle when using the
default controller.
Right-click and mouse through the check mark to exit, or double-right-click.
Tip:
An option to hide all motors is available in the right-click context menu.
In some models hiding all motors may improve performance of the
animation.
A pin can only be selected if it connects two parts or if it goes through a
single part, in which case the motor will be attached between the part and
the ground.
A motor cannot be created at a pin that connects more than two parts.
The arrow on the motor depicts the direction the shaft moves relative to the
base part. If the arrow appears stationary during motion animation playback,
then it must be the base part that is rotating.
If you intend to rigidly lock an actuator or motor that is of type=Velocity,
you should disable the controller. If you do not do so, then you will need
to adjust the PID gains in order to prevent (or at least minimize)
movement.
Suppress/Unsuppress a motor to understand its effect on your model. On the
motor, right-click and select Suppress. From the Model Browser or
Table, right-click and select Unsuppress.
State Dependent Inputs
You can assign inputs to motors and actuators that are dependent on the state of
joints, motors, actuators, systems, spring-dampers, and measures. Example input types
include Torque vs. Speed, Force vs. Angle, and Force vs. Distance.
Example: Force Applied to Blade as a Function of Blade
Angle Rotation
Select a motor or actuator.
Make the motor or actuator dependent on a variable object:
In the microdialog, click , and then select the option.
Click .
In the modeling window, select a measure, system, actuator, motor,
joint, or spring-damper to make it the independent variable.
Note: To plot results such as displacement,
velocity, and rotation, select a system. By selecting a system, you
can plot for example:
Displacement vs. Rotation
Force vs. Angular Speed
Displacement vs. Rotation
The independent variable is displayed in red.
In the Profile Editor, specify the variable range or cycle over which the input
function will be applied.
In the microdialog click Profile Editor.
Specify the variable range or cycle over which the input function will
be applied:
Option
Description
Function
Select a profile function. Supported functions
include:
Step
Step Dwell Step
Single Wave
Impulse
Table
Variable
The independent variable object (system, measure, motor,
actuator, joint, or spring-damper).
Reference Frame
The reference frame used by the variable
component.
Variable Component
The independent variable component output that the state
dependent object will monitor. Use the dropdown menu to
access to the library of functions.
One Cycle (for cyclic
rotations)
Specify the cycle range within which the V(i) and V(f)
values fall. For example, a 4-stroke piston engine will
experience combustion force every 2 revolutions (or 720
degrees) of the crankshaft.
Variable (i)
Enter the initial value of the independent variable
object (system, measure, motor, actuator, joint, or
spring-damper).
Variable (f)
Enter the final value of the independent variable object
(system, measure, motor, actuator, joint, or
spring-damper).
[Variable Object] Force
(i)
Enter the initial value of the state dependent
object.
[Variable Object] Force
(f)
Enter the final value of the state dependent
object.
Microdialog Options
Use the options in the microdialog to edit the behavior and appearance of a motor.
Click the to view advanced
options.
Figure 1. Motors Microdialog
Type
Use the θ, ω, α, T drop-down menu on the microdialog to change the type of motor.
Options are speed, angle, acceleration, and torque.
Reverse Direction
Use the +/- button to reverse the motor's direction of
rotation.
Set Speed/Angle/Acceleration/Torque
Enter a magnitude in the text field for the rotation speed, angle, acceleration, or
torque. Think of this as a target speed or angle when using the default
controller.
Note: If you enter zero for the magnitude, the motor will be locked and
most of the options in the microdialog and Profile Editor will become uneditable.
Lock the Motor
Lock the motor to prevent it from rotating. This is useful for debugging.
Time
Make the motor profile dependent on time.
Independent Variable
Make the motor profile dependent on a selected variable.
Select Independent Variable
In the modeling window, select a measure, system, actuator, motor, joint, or
spring-damper to make it the independent variable.
Profile Function
Use the profile function to change how the shaft rotates as time elapses. Examples
include step, single wave, or oscillating.
Edit Profile Function
Open the Profile Editor, which allows you to
edit profile data and view it in an interactive chart.
Use Controller
A controller is used to achieve the target speed
or angle. If you disable the controller it will use the target profile directly, which
could result in excessive deformations or other warnings.
Base Shape
Use the Base Shape option to change the appearance of the motor. To adjust the overall
size, use the Shaft Radius property in the Property Editor.
Move Motor
Click to open the Move tool, allowing you to reposition the motor.
Assign Normal to Face
Click to align the motor so it is perpendicular to the face to which it was
applied.
Motor Properties
Refine the behavior and appearance of motors using the properties available in the
Property Editor (F3).
Restrain Centerline
Use to restrain the axis of the motor so it does not move relative to the
motor base (or the ground part if no second part is defined). Choices are
Cylindrical or Revolute. By default, this property is enabled for a motor
attached to holes, and disabled for motors attached to surfaces. Disabling
this option may result in unexpected part movement, warnings, or
errors.
Base Scale
Use to change the appearance of the motor shaft and base by changing the
size of the motor.
For...
Do this
Hole-based motors
Click the gray circle patch overlaying the
motor.
In the microdialog, change the Base
Scale by doing one of the
following:
Drag the slider.
Enter a value between 0.5 and
2.0.
Shaft Radius
Use to adjust the overall size of the shaft. This property is not available
for motors applied to holes.
For...
Do this
Non-hole-based motors
Click the white arrow overlaying the
actuator.
In the microdialog, change the Shaft
Radius by doing one of the
following:
Drag the slider.
Enter a value in the microdialog.
Motors Table
The Motors table lists all of the motors in your model and allows you to edit various
attributes.
Location: Motors tool, satellite icon
Figure 2. Motors Table
To
Do this
Rename a motor
Select the cell in the table and then click again to make the field
editable.
Change the type
Select the cell in the table and then select a different option from the
list.
Sort a column
Click the column header. Click repeatedly to toggle between ascending and
descending order.
Add or remove columns
Right-click on a column header.
Shortcuts
To
Do this
Deselect a feature
Hold down the Ctrl key and left-click a selected (red)
hole or surface.
Exit the tool
Right-click and mouse through the check mark to exit, or double-right-click.
satellite icon that appears when you hover over the Motors tool to view a list of all motors in
your model.
: Make the motor dependent on time.
: Make the actuator dependent on the state
of a variable object (joint, motor, actuator, spring-damper, system, or
measure). You can then represent input relationships such as Torque vs.
Speed, Force vs. Angle, or Force vs. Distance. For details, see State Dependent Inputs.
, and then select the 
.
Profile Editor.
to view advanced
options.
