﻿ Step 5.5: Cranks, Rockers and Sliders

# Step 5.5: Cranks, Rockers and Sliders

## Cranks, Rockers, Sliders

In this step, we connect these Function-Blocks (FB):

 • A Linear-Motion FB
 • A Motion-Dimension FB
 • A Motion FB and a Gearing FB

These FBs, together, specify how and when a Crank, Rocker or Slider moves.

#### A Rocker

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A Rocker is a Part that rotates around a Pin-Joint with a motion as defined by motion-values at the input-connector of a Motion-Dimension FB.

The image shows a Rocker. To add a Rocker:

 1

The Base-Value is 40º

 2 Add a Motion FB to the graphic-area.
 3 Add a Linear-Motion FB to the graphic-area.
 4 Drag wires to connect the Linear-Motion FB to the Motion FB to the Motion-Dimension FB
 5 To edit the FBs, double-click the FB icons.

#### A Crank

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In MechDesigner, the Crank is a simplified Rocker. It rotates at constant speed.

The 'Crank':

 1 A Part joined to a 'kinematically-defined' Part with a Pin-Joint
 2 The angle between the parts defined with a Motion-Dimension FB
 3 Add and connect a Linear-Motion FB to the input of the Motion-Dimension FB

To reverse the direction of the Crank, add and connect a Gearing FB between the Linear-Motion and Motion-Dimension FB, and edit it to change the Gearing Ratio parameter to -1.

#### A Slider

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A Slider is a Part that reciprocates, back-and-forth, along a Slide-Joint.

The image shows a Slider. To add a Slider:

 1 Add a Motion-Dimension FB to a Slide-Joint

The initial position, here 7.98mm, is the 'Base-Value'

 2 Add a Motion FB to the graphic-area
 3 Add a Linear-Motion FB to the graphic-area.
 4 Connect the Linear-Motion FB to the Motion FB to the Motion-Dimension FB.
 5 To edit the FBs, double-click the icons.

See the video to the left.

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