This section will take a look at the Technical drawing syllabus in relation to the topic Cam and Follower Systems.

Cam and follower systems fall under the Mechanisms Section of the Engineering Applications Part of the Leaving Certificate Technical Drawing Syllabus

This Mechanism section goes as follower:

"Mechanisms:

Construction from given data of helical springs and screw threads.

Construction of radial plate cams to give uniform velocity, simple harmonic motion, uniform acceleration and retardation to knife edge, roller, and flat-type, in-line followers.

Construction of cam profiles and displacement diagrams.

Construction of displacement diagrams from given cam profiles.

Plotting locus of a point in link mechanisms: connectimg rod and and crank, quick return  mechanism, four bar chain.

Involute gear tooth profile: approximate method of construction.

Gear terminology and basic proportions.

Construction of gear tooth profile for spur gears, rack and pinion.

Principles of other gear types.

The Draft Syllabus

As we are all probably aware there is a new draft syllabus in circulation and, in relation to cams and follower systems, yes they do play a part in this new syllabus.   In the case of this new draft syllabus they fall under the heading of Dynamic Mechanisms. See for yourself.

"Dynamic Mechanisms

While much of the study of Techinical Drawing deals with elements that are static plane and descriptive, geometries can be equally useful in the solution if dynamic problems.  Students should be introduced to many of the 'special curves' as the path plotted by a point undergoing a dynamic transformation.  The use of models and computer simulations to depict these movements should be encouraged.

Areas to be covered:

• The common geometric loci, the helix, conical spiral, and the archmedial spiral
• Construction of loci defined by the movement of circles relative to lines, both straight and curved
• Use of trammels
• Determination of loci from linkage mechanisms
• Construction of cam and profiles and displacement diagrams
• Uniform Velocity, Simple Harmonic Motion and Uniform Acceleration and Retardation for Knife Edge, roller and flat followers 

Student learning outcomes.

Students will be able to:

• Construction the involute of a circle and regular polygons
• Construct the helix and conical spiral from given data
• Construct a spiral given the longest and shortest vector length or given a vector length and the angular increase in length
• Construct cycloids, epicycloids, Hypocycloids and trochoids and combinations of the aforementioned
• Construct tangent from a point on an involute, archimedial spiral, cycloids, epicycloids and hypercycloids
• Use a trammel to solve problems on loci
• Construct a locus of a point in a link mechanism
• Construct radial plate cams of given uniform velocity, simple harmonic motion, uniform acceleration and retardation to various followers
• Construct cam profiles and displacement diagrams
• Construct cam profiles from given cam profiles
• Understand the applications for all the curves constructed
• Construct involute gear profiles