STRUCTURES & MECHANISMS: Structural conditions /2

These pictures depict some important rules about structural conditions:

EXAM: Structures & Mechanisms (THEORY)

This is a difficult lesson, so you're going to take 2 exams:

• (1) THEORY [20th February 2018]
• (2) PRACTICE [12th March 2018]

STRUCTURES (theory)

What is the mission of a structure? Definition.

Natural and man-made structures. Definition. Identify drawings.

FORCES AND LOADS

Forces. Static effect=deform. Dynamic=move/stop. Parameters: Intensity, direction, trajectory, point of application.

Loads. Definition. Types (Fixed or permanent) and (variable). They produce stress on the structure of a body.

STRESS

Traction, compression, bending, torsion, shearing or cutting. Identify definitions, identify drawings, draw arrows and put real examples (from the student’s book).

MAN MADE STRUCTURES

Identify definitions & drawings. 

• Massive structures and lintels. 
• Vaulted structures 
• STONES->COMPRESSION. 
• Triangular structures. 
• Suspended structures 
• CABLES->TRACTION. 
• Reinforced concrete structures.
• CONCRETE+STEEL -> COMPRESSION+TRACTION. 
• Laminated structures. 
• Pneumatic structures. 
• Spatial and geodesic

STRUCTURAL CONDITIONS

Stability. Centre of gravity must be centred over its base and close to the ground. Ways of achieving stability (pictures).

Resistance. Depends on the material, quantity of material and the shape of the structure.

Rigidity. Avoid deforming considering:

• Shape. Chosen to resist compression (avoid buckling), traction and bending stress
• Rigid joints. What is corbelling useful for?
• Using triangular structures & crossbracing.

STRUCTURAL ELEMENTS

Match structural elements with their corresponding pictures (columns, pillars, lintels, arches (KEY STONE), vaults, buttresses, flying buttresses, load bearing wall, retaining wall, joists and blocks, foundations with footings, foundations with piles, suspenders and tension rods, bracing).

MECHANISMS (theory)

What is the mission of a mechanism? Definition, comparison with structures.

LINEAR TRANSMISSION

Levers, Pulleys, Fixed Pulley, Movable Pulley, Compound pulley systems.

Description, equation.

Identify drawings and give examples (from the student’s book).

ROTARY TRANSMISSION

Wheels & belts, friction wheels, pulleys with belts, interlocking gears, sprockets with chains.

Description, equation.

Driver & Driven wheel concept

Identify drawings and put real examples (from the student’s book).

TRANSFORMATION OF MOTION

Winch and crank, rack and pinion, crank and rod

Description, equation.

Identify drawings and put real examples (from the student’s book).

STRUCTURES & MECHANISMS: Vocabulary (structures)

Flashcards game

Source: Carolina

STRUCTURES & MECHANISMS: Structural conditions

Watch this intriguing video:

Playing this game, you can practice structural conditions in a funny way:
(Click here if your browser doesn't show it)

STRUCTURES & MECHANISMS: Vocabulary (mechanisms)

Practice vocabulary with these 2 interactive activities:

Flashcards

Speller game

Source: Carolina

STRUCTURES & MECHANISMS: Pulleys

Here's an in-depth explanation of pulleys (activate subtitles if necessary):

STRUCTURES & MECHANISMS: Let's play!

In this lesson we're going to have fun playing 2 interesting games:

• STRUCTURES: West Point Bridge Designer
• Download EXE setup file from here
• Sample Youtube tutorial below

• MECHANISMS: Gears & Chains
• Visit this web link if you see a "Get Adobe Flash" icon

EXAM: Wood & its derivatives

This is a guide to study this lesson.

• ALL key concepts
• ALL proposed exercises  
• Getting wood process
• Classifying wood: harwoods (decidious trees): beech, oak, mahogan / softwoods (conifer): pine, silver fir, white poplar.
• Derivatives of wood
• Engineered wood: plywood, chipboard, fibreboard
• Cellulose materials (the process of making paper)
• Properties of wood
• Key concepts
• Cut against the grain or with the grain
• Equipment, tools and machines (identify pictures, name them, classify them...)
• Measuring
• Drawing marks & lines
• Cut & saw
• Drill
• Curve & plane
• Sand
• Join
• Painting
• How to use: handsaw, fret saw, gimlet, rasp, sandpaper

[PRJ] R/C vehicle

This will be our project: a Remote Controlled vehicle (car, van, tractor, truck, quad, dumper....)

Its construction will involve applying several technical skills (mechanics, electricity, wooden handicrafts...)

Useful web pages:

• LOGKIT 1845 (to help you with your freehand sketch, page 5)
• Paco Ruiz's Blog (images, videos & construction)

Please note, here are some important details (to simplify, they can only turn in one direction when moving backwards):

Our DC motor with reduction gearbox and our available tyre sizes force us to install it into the vehicle chassis in this position (unless you want to use bigger tyres):

Approx. dimensions of this mechanical part are:

[width x height x depth] (as seen in above photos)

34 x 55 x 33 mm (without external gears)

55 x 55 x 44 mm (with external gears & mounting tabs)
150 mm axle track (as shown in picture below)

Watch these videos to see some vehicles in action:

Source: Paco Ruiz

Technical Drawing: 3D objects (2)

In this link you will find some more difficult & useful 3D objects:

• 3D objects (2)

Hidden lines are important!

EXAM: Graphic expression in technology

Here are some possible exercises:

- All key concepts (in the margins)

- Definitions
- Types of pencils
- Paper size, weight, finish
- Differences between sketches, diagrams, technical drawings (draw / identify them)
- Use of ruler, protractor, triangle and set square (angles, parallel, perpendicular lines...)
- Scales: (angles are the same, but lines are different) / identify enlargement & reduction / draw an object at a different scale / graphic scales / choose the best scale to represent an object
- Annotation: line standardization, symbols, MILLIMETERS, annotation rules in 2D & 3D
- Viewpoints: front, side, plan view (placed correctly), don't forget correspondence between viewpoint lines!
- Draw an isometric view from orthographic views

Good luck!

SKETCHUP: Download & Install

Please find below some useful links to download & install Google Sketchup:

All products:
https://www.sketchup.com/es/download/all#es

SketchUp Make 2017 (Windows 64 Bit) (English)
http://dl.trimble.com/sketchup/2017/en/sketchupmake-2017-2-2555-90782-en-x64.exe


If you don't want to install it on your computer, you can use SketchUp Free in your Web Browser:
https://app.sketchup.com/app?hl=es

Any questions? please drop me an email.

SKETCHUP: Guide to build 3D objects

Please, watch these videos to get an idea of the process you would follow to build your assigned 3D object:

• Solid construction #1
• Solid construction #2
• Solid construction #3

Right-click on the toolbar and add these 2 toolsets (VIEWS & STYLES) to be able to switch viewpoints and material properties (transparency):

VIEWS: (for better results, activate "Parallel projection" in Camera menu)

From left to right: ISO, TOP, FRONT, RIGHT, BACK, LEFT view.

STYLES:

In order to fit the solid in the right position, please make sure you start drawing in the following axis orientation:

(Object 4)

How to draw an isometric view from orthographic views

It's hard, but not impossible, here's a graphical tip:

Place the orthographic views:

Then extend the projections:

Now it's time to practice, click on the link below:
Isometric drawing (RaulTecnologia)

Orthographic Projections

Watch these videos for a better understanding of Projections:

1. European System

2. European System (in Spanish)

3. European System (1st angle projection) VS American System (3rd angle projection)

Now it's time to practice with Diedrom, click on the link below:
http://moebio.com/santiago/diedrom/diedrom.html

Technical Drawing: 3D objects

Hi!

Study pages 16 & 17 from the book and remember what has been taught in class.

Here there are the 3 coloured objects we've studied in class (Google Sketchup file format):

• Object1
• Object2
• Object3

If you want to open the previous files, you must install Google Sketchup Make release.

Let's practice drawing the different viewpoints of these new 3D objects.

;)

EXAM: The technological process

In this post you can find a simple guide to study this exam: (apart from what I told you in the previous review class)

- All key concepts (in the margins)

- Definitions: Technology, technological process, sustainable development

- Factors in technological process: Enumerate them

- Classroom workshop: Draw a plan, identify its areas, objects...

- Safety rules: choose true or false from a given list

- Signs: classify them, enumerate their characteristics, draw a sign of your choice

- Group organization: posts & duties

- Stages of the technological process (4): establish relationships with sequence in section 1

- Fill in a Progress Status Sheet, a Production Estimate table

- Materials for technical use: Enumerate, applications & types

- The influence of technology on society: do not study all characteristics, do not memorize all objects or systems developed (3 will be ok)

Good luck!

Start... from SCRATCH!!!

Hi!

On Thursday we're going to start coding in a visual way using SCRATCH from MIT.
Please, create an account using one of your parents email (click on "join Scratch").
Please Note: They will receive an email and must give authorization.

https://scratch.mit.edu/

Happy coding!

Welcome!

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