Engineering Year 10 Semester 1

Define Linear Motion

Motion along a straight line, measured in displacement (m) and time (s)

Examples of Linear Motion

Train moving along a straight track, sliding door

Define Rotary/ Circular Movement

Occurs when an object rotates or spins around an axis

Examples of rotary motion

wheel of a bike, chuck of a drill

Define reciprocating motion

repetitive back and forth or up and down motion along a linear path

Examples of reciprocating motion

sewing machine needle, piston in a car engine

Define Oscillating motion

body moving to and fro about a mean

3 conditions must apply

* the body must have inertia to keep it moving through the midpoint of its path
* there must be a restoring force (elasticity, gravity) to accelerate the body to its midpoint
* the friction acting against the motion of the body must be small.

Examples of oscillating motion

* pendulum in a grandfather clock
* wiper blades in a car
* a swing
* vibration of a string on an instrument

Define periodic motion (basically the same as oscillating motion)

Any motion that repeats itself at regular intervals. The smallest interval of time after which the motion is repeated is called the period

The period is represented by the letter T and for small angles of oscillation can be approximated by the equation

Examples of conversion from rotary to linear

Winch and drum, conveyor, rack and pinion

Examples of conversion from rotary to reciprocating

crank and slider, cam and follower

rotary to oscillating examples

linkage systems, pin and slot systems

Define machine

means of overcoming a resistance called the load by the application of a force called the effort

Define and provide a formula for velocity ratio

ratio of distance through which the effort moves to the distance through which the load moves at the same time

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Define and provide a formula for mechanical advantage

ratio of the load to the effort

What is the relationship between the mechanical advantage and velocity ratio assuming that no work is done lifting any parts of the machine and friction is ignored and what does this imply?

VR = MA

What is the velocity ratio of a pulley belt drive system?

For what is a pulley belt drive system used

to transmit rotary motion from one shaft to another over a large distance

Characteristics of a pulley belt drive system

* used when shafts are too far apart to use gears
* direction of rotation of the driver and follower are same unless the belt is twisted
* quite
* no need for lubrication
* will slip if transmitting large forces (+ or -)
* if you don’t want it to slip use a toothed pulley and belt
* there is tension and slack
* works on friction between the pulleys and the belt

What is the velocity ratio of a chain and sprocket drive system?

Characteristics of a chain and sprocket drive system:

* noisy
* requires lubrication
* transmits large forces without slipping

What is the velocity ratio of a spur gear drive?

characteristics of a spur gear drive:

* transmits large forces without slipping
* usually requires lubrication
* noisy
* driver and follower rotate in opposite directions unless there is an idler gear in the middle

What is the total velocity ratio for a compound gear drive?

What is the velocity ratio of a worm and wheel drive?

Characteristics of worm drive systems:

* large increase in VR with only 2 gears
* only worm gear can be used to drive the system
* due to high inertia the system will lock into place when power is switched off
* high torque
* quiet

What is the distance moved by a rack and pinion drive?

characteristics of rack and pinion system

* rotary motion is converted to linear motion and vice versa
* noisy
* requires lubrication

What are 2 formulas for linear velocity?

What is the output speed in terms of RPM for a drive system?

Breadboard

Prototyping circuits without the need for soldering 

Raspberry Pi Pico 

An integrated circuit that contains a microprocessor along with memory and associated circuits and that controls some or all of the functions of an electronic device (such as a home appliance) or system. 

Switch SPDT

A single pole double throw allows the user to change the flow of current through two circuits. 

Infra red remote control 

Used to create a wireless connection between devices. 

LM7805 Voltage regulator 

Controls voltage. Allows the user to design circuits that have multiple voltage sources. From a large voltage to a smaller. In claw machine project we went from 9 to 5 volts. 

Resistor 4 band 

Restricts the flow of current and can be used to control voltages in a circuit. 

Battery Pack

Made up of multiple cells (one battery) to provide a known voltage supply to a circuit. In your project you joined them in series which increased the voltage but kept the current the same.

H Bridge

Used to simplify wiring and circuits. Needs separate power supply. Allows control of motors direction via microcontroller.

DC motor

Used for continuous rotation that does not require specific positioning. Has two wires.

Servo Motor

Used for precise positioning. 

Rotation 0 - 180 degrees for SG-90 

Has three wires