Cylindrical Cam: Difference between revisions

Latest revision as of 13:44, 28 August 2016

Description

Cylindrical Cams (aka Barrel Cams) are used mainly to convert rotational motion to linear motion parallel to the rotational axis of the cylinder.

A Swashplate may be regarded as a simple form of cylindrical cam.

Features and Applications

Properly machined cylindrical cams, as used in engine gearboxes for example, may have slots milled into the side of the cylinder such that the follower is positively driven each way and does not rely on a spring for its return.

Note: They can be modelled by constructing a Displacement Diagram to use as a Template then cutting it out of paper and wrapping it around a tube to show the profile to be cut.

Animation

Examples from Nguyen Duc Thang's YouTube Channel 2100 Animated Mechanical Mechanisms

Barrel Cam with milled grooves is used in sewing machines to guide thread.

Facial Cam - double ended to increase follower stroke without changing the pressure angle. Gravity maintains contact between rollers and cam.

DT Online Buyers' Guide

Cam profiles (i.e. the shape of the outer edge of the cam against which the Follower engages) can be drawn as a Displacement Diagram using Drawing Instruments or CAD software.

Cams for models can be made simply by drilling an MDF or Ply Disc off-centre to make an Eccentric Cam or by mounting a disc at an angle to a dowel axle to make a Swashplate.

The use of Cams can most easily be explored using Contruction Kits such as those listed below.

Click top left to enlarge


Engino "STEM Mechanics" Cams and Cranks Set	Engino "STEM Mechanics" Levers and Linkages Set	Fischertechnik 536622 - Mechanic & Static 2	Engino Mechanisms Set	Engino Gears Set

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 | [https://youtu.be/qYRU5eu1HHI '''Barrel Cam'''] with milled grooves is used in sewing machines to guide thread.
-| {{#ev:youtube|qYRU5eu1HHI|200x200|right||frame|loop=1&autoplay=1&playlist=qYRU5eu1HHI}}
+| {{#ev:youtube|qYRU5eu1HHI|200x200|right||frame|loop=1&autoplay=0&playlist=qYRU5eu1HHI}}
 | [https://youtu.be/THHlXrYS_-4 '''Facial Cam''']  - double ended to increase follower stroke without changing the pressure angle. Gravity maintains contact between rollers and cam.
-| {{#ev:youtube|THHlXrYS_-4|200x200|right||frame|loop=1&autoplay=1&playlist=THHlXrYS_-4}}
+| {{#ev:youtube|THHlXrYS_-4|200x200|right||frame|loop=1&autoplay=0&playlist=THHlXrYS_-4}}
 |}