Mechanical Design 101


Planar, Spherical and Spatial Four-bars

Synthetica 3.0 release

Computer Aided Linkage Synthesis

Courses in Mechanical Design

This linkage animation shows a three-piece convertible top similar to the Volvo C70 taken from US Patent 6,857,687 (Gernot Bruder, CTS Fahrzeug-Dachsysteme, GmbH). Front and rear parallelograms are driven by links connected to the couplers of two drive linkages (cyan and magenta) that are joined to the same input crank, which in turn is driven by a link connected to the red parallelogram drive system.

A six-bar linkage designed to adjust the position of a brake pedal.

A simple walking machine with spherical four-bar linkages guiding each leg.

This animation shows a Watt-1 six-bar linkage moving through five task positions. The design was achieved by Gimsong Soh by first synthesizing the 3R backbone and then two 2R chains. Select here for the .mov file.

Six-bar Linkage Synthesis from Summer 2005

This is the linkage that deploys the top of a 1991 Mustang convertible. Notice that it is essentially a 3R chain with four-bar linkages controlling the joint angles. Christy Mescher generated this animation using SolidWorks. Select here to see a QuickTime movie.

Mustang Convertible Linkage Animation

Four-bar Linkage Animations from Fall 2004

Here are five examples of computer aided linkage design from my Fall 2004 class MAE 183. In each case five positions or orientations are specified, and the linkage is designed to move smoothly through them. (Double-click on the images to run the QuickTime .avi files linked to them.)

1. Here is a planar linkage designed to open the petals of a flower.

2. This is a spherical linkage designed to move Africa. The orientations move from 225 million years ago through to today.

3. This spherical linkage drives the oars of a scull. In the return stroke the oar rotates to the horizontal to reduce air resistance.

4. This spherical linkage moves a plane from vertical to horizontal orientations. It was designed to deploy a tabletop and return, but looks like a swimmer when it cycles.

5. This is another linkage designed to reorient a plane from horizontal to vertical but now configured to move a folding wing between stowed and deployed orientations.

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