MotionDesigner Reference & User Interface > Motion Laws > Constant-Velocity : Specify Two Positions

Constant-Velocity | Two Position

This is the Flexible-Polynomial motion-law.

Its Control-Buttons define its Start-Position and its End-Position. All other motion-values are NOT specified.

It is not defined with a Velocity.

You need to specify the End-Velocity at the end of the Previous-Segment to equal the Start-Velocity of this segment, to avoid a Velocity discontinuity.

Flexible-Polynomial : Two Position | Constant-Velocity

SEGMENT EDITOR: Control-Buttons for a 'Two Position | Constant-Velocity motion-law.

STEP 1.Use the Motion-Law Selector to select a Flexible-Polynomial motion-law

STEP 2.Select the Segment and open the Segment Editor

STEP 3.De-select ALL Match (Flow) Control-Buttons

STEP 4.De-select Start-Velocity, Start-Acceleration, and Start-Jerk Control-Buttons

STEP 5.De-select End-Velocity, End-Acceleration, and End-Jerk Control-Buttons

STEP 6.Select the Start-Position and End Position Control-Buttons

STEP 7.Enter the Start-position and End-Position

STEP 8.Enter the correct X-axis values.

The Acceleration and Jerk Values at the start and end of the segment are zero.

Constant-Velocity: 'Conveyor' Motion-Law

Note:

You can use a Gearing FB, to replace a Motion FB when the Constant-Velocity is for a machine-cycle - assuming a Linear-Motion FB is connected to the input of the Gearing FB.

When the Gearing-Ratio is 1, the output will be from 0 to 360. If you enter 240/360 as the Gearing Ratio, the output will be from 0 to 240.

Thus, you can see it is easy to enter a Constant-Velocity when it continues over a machine-cycle.