Linear-Motion FB

Summary of Linear-Motion FB

The default motion-values at the output-connector of the Linear-Motion FB are equal to the Master Machine Angle.

Thus, its output continuously increases from 0 to 360, again and again.

You can edit its output with the Linear-Motion FB dialog-box to add or subtract a constant value from the Master Machine Angle [MMA]. If you do this, the output becomes 'before' or 'after' the MMA.

Note: You must use a Linear-Motion FB in the 'first' kinematic-chain in the 'first' Mechanism-Editor.

Add and Edit Linear-Motion-FB



Kinematics FB toolbar > Linear-Motion FB [right of Graphic-Area]


Add menu > Add Gearing FB


STEP 1: Add the Linear-Motion Function-Block to the graphic-area

1.Click the Linear-Motion FB in the Kinematics FB Toolbar.
2.Click again in the graphic-area to 'place' the Linear Motion FB in the graphic-area.

The Linear-Motion FB is now in the graphic-area.


STEP 2: Open the Linear-Motion FB dialog-box:

1.Double-click the Linear-Motion FB in the graphic-area.

- or -

Linear-Motion FB dialog-box

The 'Function' of the Linear-Motion FB:

Output motion-value = Master Machine Angle + Constant

Optionally, select the Accumulate option, so that the output does not reset to 0 after each machine cycle.

The 'Function' of the Linear-Motion FB is then:

Output motion-value = (Revs * 360) + Master Machine Angle + Constant

Linear Motion FB dialog-box

Linear Motion FB dialog-box

Linear-Motion FB dialog-box:

1s-red Machine Angle +

Enter a motion-value in the Machine Angle + 'data box'.

Example: Machine Angle  = '53.4'.

Thus, if the Master-Machine-Angle = '120', the output motion-value from the Linear-Motion FB = 120 + 53.4 = 173.4

When the Machine-Angle is:
'Positive'[+ve]  : output is 'before' [it 'leads'], the Master Machine Angle.
'Negative'[–ve] : output is 'after' [it 'lags'], the Master Machine Angle.

2s Output Options:

Reset after one Cycle [default option and most typical]
Output = Master Machine Angle + Value

- or -

Output = (Revs * 360) + Master Machine Angle + Value

Click the OK-tiny-11-15 to close the dialog.

Notes 'Accumulate' or 'Reset after one Cycle' :

Normal use: Reset after one Cycle

Use 'Accumulate' if you want to model a watch, or a mechanism that does not have a motion-period equal to the Master-Machine-Angle.

Tutorial and Reference Help Files for MechDesigner and MotionDesigner 13.2 + © Machine, Mechanism, Motion and Cam Design Software by PSMotion Ltd