Objective of this Step
In this step, we specify the motion to the Part as Constant Angular Velocity - also termed Uniform Rotation Motion.
We also learn how to connect wires from output-connectors to input-connectors of different FBs (Function-Blocks).
See also:
In MechDesigner, a Motion-Part has its motion defined by the input to a Motion-Dimension FB and the Base-Value parameter defined in its dialog-box.
A Rocker is the kinematic name in the Kinematics-Tree for a Motion-Part that may rotate continuously or oscillate back and forth.
In a Machine, a Rocker is a nearly always a machine element that 'oscillates back and forth'.
|
Terminology Reminder:
| • | kinematically-defined Part : a part that has zero degrees of-freedom. |
| • | Connect a wire : ... to drag a wire from the output-connector of a Function-Block to the input-connector of a different Function-Block. |
| • | Motion-Values : flow instantly along wires from FB to FB |
|
Summary of this Step
| 1. | Review the Kinematic-FBs, the Master-Machine-Angle, the Animation-Speed |
| 2. | Add a Linear-Motion FB - also called a 'Clock' |
| 3. | Connect a wire from the output-connector of the Linear-Motion FB to the input-connector of the Motion-Dimension FB |
| 5. | Add, connect and edit a Gearing FB to rotate the Part in a clockwise direction |
Video
Video of this Step
|
How to add a Linear-Motion FB and join the FBs with wires'
|
|
We:
| • | Use Kinematic Function-Blocks to give motion-values to and |
| • | Connect wires between Function-Blocks (FBs) from output-connectors to the input-connectors of a different Function-Block. |
The schematic, to the left, attempt to show how you can connect wires between the Function-Blocks.
|
Motion-Provider: have output-connectors. The motion-values are either the MMA or found from the motion measurement of a Part or Point in a kinematically-defined chain.
Motion-Processor: use the motion-values from Motion-Providers as the independent variable for their internal function. You can actively design their functions.
Motion-Part: identified by Motion-Dimension FB. Its motion is specified by the motion-values at the input-connector to the Motion-Dimension FB.
Motion-Point: identified by a Motion-Path FB. Its motion is specified by the motion-values at the input-connector to the Motion-Path FB.
|
|
Tutorials Steps:
Add a Linear Motion FB; Connect to the Motion Dimension FB
|
| STEP 1: | Click (right of the graphic-area)
- or -
Click
- or -
Right-click in the graphic-area, and select the Linear-Motion FB icon in the contextual-menu. |
|
|
| STEP 2: | Click in the graphic-area. |
MechDesigner adds the Linear-Motion FB to the graphic-area.
Hover+Drag the Linear-Motion FB in the graphic-area to the left of the Motion-Dimension FB.
It is easier to connect the FBs together.
|
|
| STEP 3: | Connect Function-Blocks with wires. |
See how:
The motion-values at the output-connector of the Linear-Motion FB are now also at the input-connector of the Motion-Dimension FB.
The Motion-Dimension = Output from Linear-Motion FB + Base-Value - see Motion-Dimension dialog-box
|
|
Cycle the kinematic-chain.
| STEP 4: | Click
- or -
Click
- or -
Press ALT+C keys on your keyboard to start and stop the cycle command. |
|
The Crank rotates one time with each Machine Cycle. Watch the red pointer under the Master-Machine-Angle move from 0 to 360 each time the Part rotates one time.
|
Rotate the Part in a Clockwise direction
|
As motion-values increase from 0 to 360, the Crank rotates in a counter-clockwise direction. Thus, the positive kinematic direction of an angle is the counter-clockwise direction.
To rotate the Crank in a clockwise direction, we will use a use a Gearing FB (I prefer to use the Gearing FB).
| STEP 2: | Click in the graphic-area. |
|
|
| STEP 1: | Delete the wire between the Linear-Motion FB and the Motion-Dimension FB |
To delete a wire:
| 1. | Click the wire in the graphic-area |
| 2. | Click your delete on your keyboard, or use the method in the Selection-Window |
| STEP 2: | Connect the Linear-Motion FB to the Gearing FB, and the Gearing FB to the Motion-Dimension FB |
|
|
Now we can open the Gearing dialog-box
| STEP 5: | Double-Click the Gearing FB |
| STEP 6: | Edit the Gearing Ratio parameter to . |
| STEP 7: | Click  to close the Gearing Dialog-Box. |
| STEP 8: | Click
- or -
- or -
Press the ALT+C key on your keyboard |
The Crank now rotates in a Clockwise direction.
|
|
Other Notes:
Master Machine Angle (MMA)
 Master Machine Angle in the Feedback Area
|
(Read-Only) box is a counter for each time the machine angle progressives from 0 to 360.
(▲): below the MMA scale, indicates the Master-Machine-Angle approximately
(Read/Write) indicates the Master Machine Angle exactly.
To edit the
Approximately : Drag, to the left or right, with your mouse-pointer above the MMA scale.
Exactly : Enter a new value with keyboard in the box.
|
Animation Speed
 Animation Speed Slider in the Feedback Area |
|
The Animation-Speed does not change kinematic results.
| • | Drag, to the left or right, with your mouse-pointer above the Animation-Speed Slider scale. |
The Simulation-Speed will change the kinematic results.
|
