Irregular

Irregular motion is motion with no obvious pattern. It is often needed in automata to recreate the movements of living things.

Irregular motion is usually created using a cam or series of cams

Irregular motion is not often used as the starting point for a mechanism. It can, however be translated and transformed as shown below.

Transformations

Increase / Decrease Lever.
Reflect Pulley.
Lever.
Bell crank.
Rotate Bell crank.

Intermittent

Intermittent motion is motion which starts and stops regularly. For example, in a cinema projector the film needs to be moved on one frame at a time then held stationary while the light projects it onto the screen. This is usually done with a geneva stop as shown here.

Intermittent motion is usually the end result of a mechanism rather than the starting point for conversion.
Transformations
Increase / Decrease Lever
Gear
Reflect Pulley
Lever
Rotate Bell Crank

Oscillation

Oscillation is back and forth motion about a pivot point. It is measured in terms of both the angle of throw (amplitude) and the period of time for one complete cycle (periodic time) or the number of cycles in a given time (frequency). Oscillation tends to be an ending point for a mechanism rather than the starting point, however some mechanisms are available to convert or transform oscillations.

Oscillation to:

Transformations

Linear Motion     Increase / Decrease Gear
Reciprocating motion Crank
Cam
Reflect
Rotary Motion Crank   Rotate Bell Crank
Intermittent Motion Ratchet
Irregular Motion Cam

Reciprocating

Reciprocating motion is back and forth motion. In the example to the right the reciprocating motion of the piston is converted to the rotary motion in the crank.

Reciprocating motion is measured by its throw (the distance between the two extremes of motion) and by its period (the length of time for each cycle)

Transformations

Linear Motion     Increase / Decrease Lever
Rotary Motion Piston   Reflect Pulley
Lever
Intermittent Motion Ratchet
Irregular Motion

Rotary Motion

Rotary motion is motion in a circle. It is the starting point for many mechanisms.

Measurement:

Rotary motion is measured in either angular velocity, the number of degrees turned in a given time, or in revolutions per minute (rpm).
The direction of turn, either clockwise or anti-clockwise is also part of the measurement of rotary motion.

The strength of rotary motion is known as the torque, the turning force. Torque is measured in Newton Metres defined as the force of one newton acting at a perpendicular distance of one metre from the axis of rotation.

Conversions

Rotary motion to:

Transformations

Linear Motion Wheels.
Rack and pinion.
Increase / Decrease Gears.
Chain.
Worm gear.
Reciprocating Motion Piston.
Geared mechanism.
Cardan gear.
Reflect Gears.
Oscillation Crank.
Quick return.
Rotate Bevel gear.
Intermittent Motion Geneva Stop.
Irregular Motion Cam.

Linear Motion

Linear motion is motion in a straight line. It is the most basic of all motions. Uninterrupted objects will continue to move in a straight line indefinitely. Under every day circumstances gravity and friction conspire to bring objects to rest.

Linear motion is measured in two parts. Speed, and direction. Together these make up the velocity.

Linear motion, is not often used as a starting point for mechanisms. Click on the links below to find how to convert linear motion to other motion types.

Conversions

Linear motion to:

Transformations

Reciprocating Motion     Increase / Decrease
Rotary Motion Rack and Pinion   Reflect Pulley
Lever
Oscillation     Rotate Bell Crank
Intermittent Motion
Irregular Motion