Unit 2: Grade 10 Technological Design - Robotics - Technical Sketching

This unit will introduce you to communicating your ideas using technical sketching standards. Learning technique, format, methods will be practiced and then applied to a design challenge.

Course Units and Descriptions
Unit Description
Review course outline for more details
1 Careers & Safety- Intro, computers, organization, and careers
2 Technical Sketching- freehand sketching, ortho, dimensions, ISO views, custom ortho design
3 Basic 2D & 3D CAD Intro- 2D coordinates, lines, ortho views, 3D drawing, and custom design digitized
4 3D Parametric Design- 2D sketch, 3D parts, feature tools, drawings, exporting for 3D printing
5 Sheet metal Design- thin material design, folds, assemblies, 2D print, project design, testing, and build
6 Robot Assembly- part reproduction, part assemblies, custom function design and build
7 Web Portfolio- Showcase course work, projects, and understanding with web portfolio and presentation
Unit Content Activity Quick Links, Click to Jump to Specific Activity!
  1. Unit 2, Act. 1: Technical Sketching
  2. Unit 2, Act. 1: Custom Orthographic Design - Key Ring Accessory
sketching sample

- TOP - Unit 2, Act. 1: Technical Sketching next

Situation:

A class of students interested in the field of Engineering have taken a course to find out what Technology Design is all about. Coming up with solutions is what Engineers do on a daily bases. How they communicate those ideas is critical and one of those ways is with technical sketching.

challenges

Problem/Challenge:

Practice your sketching techniques with sketching practice assignments while learning about engineering drawing standards. As sketching is the fastest way to communicate, learn, and practice these standards, we will use several related assignments to fast forward our knowledge and skills to better prepare for application in CAD programs in the near future. These sketching projects will include:

  • Basic sketching techniques
  • Sketching basic shapes including wire-frame and isometric formats
  • Selecting front view of an object
  • Orthographic projection
  • Sketching layout and line types
  • Dimensioning object views

Related assignments will be found below in the Create & Construct section.

Investigation/Ideas:

Investigation

Communicating your ideas is key for Engineers and is a critical skill to learn. Technical sketching is used in all kinds of situations. Thumbnails are where ideas initially start... some of the greatest ideas started on a napkin in a restaurant for example. Full size sketches take a little more work and formality to the steps of creating a clean technical sketch. Best way to get started is to practice sketching simple line exercises, then basic shapes, then more complex shapes. After you feel comfortable with these sketching techniques, learning about orthographic drawings will help you effectively communicate your idea in detail through isolated views. This section will give you some more information on orthographic drawing process to use with your orthographic sketch exercises:

Selecting Front Viewortho

When deciding which view is to be used for the front view, three rules are used to determine this in the engineering field as a standard. The reason for these three rules is to prioritize and show the best views, create a standard set of views for any object, keep the view the least complicated, and make use the paper space standards, usually landscape. Objects in the real world, say for example a car has a front view, but the orthographic engineering front view most likely will be side drivers side in third angle project standard used here in North America. You must look at the object you are going to draw or sketch and decide which view shows the:

  1. The most detail
  2. Least amount of hidden lines
  3. Length across the page (as layout is usually in landscape format)
Orthographic Sketching Major Steps
steps

By following these steps in order, will give you best results in a quick and efficient manner (remember class demo):

  1. Start by visualizing the approximate shape and size of your front view, and how much space needed for dimensioning
  2. Block in your views using construction lines starting with your front view, then your spacing, top view and right side view leaving room for your isometric view
  3. Block in your major view features using construction lines so that they will all align with each other
  4. Darken your object lines for all views including outline, features, and hidden lines
  5. Start dimensioning using construction lines to add ladder distances out from view envelopes 10 mm and 8 mm thereafter
  6. Ensure you are following dimensioning rules/standards in placement, locations, alignment, and spacing
  7. Create extension and dimension lines along with small thin arrows 2 mm thick by 3 mm long with dimensions 3 mm high
  8. Last, create your isometric by blocking in a wired cube/rectangle using additive/subtractive construction build sketch process with construction lines, then darken your object lines

Tip Some points to keep in mind when dimensioning:

  • Minimize the amount of dimensions to keep less cluttered
  • Show overall and detailed dimensions to show feature locations and size
  • Overall dimensions should be furthest out with detail dimension in between object view and overall
  • Avoid placing dimensions on the actual view
  • Avoid placing dimensions where dimension lines cross extension lines
  • Extension lines may cross each other freely
  • Extension lines may cross the lines of the drawing to dimension features properly
  • Stay inside the envelope as much as possible
  • Space the dimensions about 3/8" or 10 mm from the object and 1/4" or 6 mm apart thereafter
  • Dimension on view that shows the feature best
  • Draw all arrowheads about 1/8" or 3 mm long and very narrow
Sketching Support Pages

Below are some tips that you can use when sketching objects with orthographic views and dimensioning

Line types

Line Types

Line types

Arrows

Line types

Lettering

Line types

Dimensions 1

Line types

Dimensions 2



Resource Links
links

Below are several resources you may check out that relate to technical sketching:


Common Mistakes When Sketching Orthographic Views of Objects

Some common mistakes students make when sketching objects for orthographic views are:

  • Not selecting the correct front view, review and apply all three rules for selecting front view
  • Sketching relative sizes to dimensions of object or object features
  • Not aligning object views and/or also feature details in each view -use construction lines to line up
  • Ensure arrow sizes are thinner, ratio of 2:3 - width to length, and ensure they are touching extension lines
  • Line weights are not correct, remember construction lines are light and thin to show build of sketch, object lines are thick dark showing object views, dimension lines are thin with a medium weight and include an open gap in centre for the actual dimension which is always written the same direction as page view orientation

Create/Construct:


steps to take

Sketching Exercises

The following sketching basics and sketching shape assignments are to be practiced in class and handed in for check, before moving on to the next sketch assignment. You will need blank paper and a pencil to complete the following assignments.:

Sketching Basics

Sketching
Basics

Sketching Shapes

Sketching
Shapes

Sketching Tips
tips
  • lettering sizing is generally 6 mm for titles, 3 mm for normal
  • Using two parallel lines will ensure consistency and straightness
  • speed will smooth out your lines (remember bicycle analogy)
  • ensure circles are large (full size, using up most of the space)
  • create circles using cross-hairs first, then marking space from centre, then smooth circle hitting all space marks
  • try to keep page straight to practice different directions
  • include all text and sketching for full marks,some forget to fill in the two key points below the title and reference
  • don't erase, just keep practicing and use back or another sheet if necessary
  • start a new sheet and staple all of your practice sheets together, with final (best one to be marked) at the front
  • don't worry so much about stopping exactly at each corner of objects
  • practice on back and Astrix the ones you would rather the instructor mark
  • making shapes a light construction line for the base line will help with shape creation
  • for complex shapes, use additive or subtractive sketching methods

challenge Want a challenge, check out this multi-shape sketch with shading. Working with multi shapes, lining up, hidden, space and size relationships can really test your technical sketching skills and techniques.

Orthographic Sketches

The following three images are showing a third angle projected orthographic sketch and dimensions would look like using a standard "step block" shape with a circular hole going through the center of the bottom step.

  1. Using a full blank page, (use the tips and suggested tips in the ideas/investigation section above for more help) start drawing the layout, then add the dimensions, and then label all the related terms associated orthographic projected views and dimensioning
  2. On the back copy the section below titled "Selecting Front View" with the three rules selecting a front view
  3. Bring ortho note to teacher to check (mark) before starting step 4
  4. Select a block sample, select the front view, sketch out the front, top, and right side view showing overall and detailed dimensions as in previous graphic note. No need for labels.
  5. Sketch the isometric in the top right corner.
  6. Bring to teacher to mark

Below, PDF 1 - 7 is a orthographic note, shown in order of creation, from blocking in views to finished sketch. After, labels that are not normally included in a finished sketch is for your detailed information about the process, parts of the sketch, sizing, and locations of specific components sketched.

Sketching Ortho Components labeled

7, Labels done
(only for info)

blocks

Block Samples
Ortho-Practice


Tip Remember your sketching techniques you learned above while you sketch this out:

Evaluation:

An PDF orthographic summary sheet, sample, rubric, and checklist handout is to be used to see if you have completed orthographic projection sketches correctly and can be helpful in earning higher marks using the checklist with the rubric. Complete the Sketch Ortho Self-Peer Checklist and staple to the back of your completed custom ortho block sketch project. You will be evaluated based on the completion of the above sketching assignments. Here are some student samples to check out that show some teacher feedback and marks in PDF PDF's; Sketching Basics, Sketching Shapes, and Sketching Ortho Projection Demo, Sketching Ortho Custom Blocks

Evaluation Breakdown Component Descriptions Marks
Always double check that you have completed all components for full marks.
Sketching Basics - clean, straight lines, and smooth round circle curves 10
Sketching Shapes - clear shapes sketched with correct angles, lines, and shapes 15
Orthographic Sketch Note - 3 ortho views, 1 ISO, dimensions, and labels 20
Orthographic Sketch Practice - 3 ortho views, 1 ISO, and dimensions 20
Orthographic Sketch Test - 3 ortho views, 1 ISO, and dimensions 20


SPICEj Design Process

- TOP - Unit 2, Act. 1: Custom Orthographic Design - Key Ring Accessory

Situation:

A class of students interested in the field of Engineering have taken a course to find out what Technology Design is all about. One of the major principals of this course/field is the "Design Process". Coming up with solutions is what Engineers do on a daily bases.

Problem/Challenge:

challenge

This is a three parts to this activity, with the first part understanding the design process and identifying the steps on different tasks/challenges such as coming up with ideas for a Key ring accessory using this process. Your task is to use the design process model, SPICE to design a practical/decorative key ring accessory to be later drawn in CAD and printed in 3D using our 3D printer. A hidden aspect of this activity is also to practice and show your sketching ability for creating thumbnail ideas, and also creating an orthographic with dimensions and isometric of your idea. The key chain accessory itself has specific requirements which is to include:

  1. A design that is unique to you, custom, practical/decorative, and related to technology
  2. Equivalently sized to approximately the size of a chap stick container or standard Staedtler white eraser
  3. A minimum 5 mm diameter hole for the key ring with at least 5 mm sufficient support material around the hole
  4. A minimum 5 mm general thickness

You will need to explain the SPICE design process steps first in how it is applied to the key ring accessory, before actually starting to design it. The following are the major steps for this project:

  1. Start by explaining filling in the steps of SPICE explained in terms of this project, the key chain accessory design
  2. Create five different isometric thumbnail ideas based on above parameters with each idea labeled, filling the page
  3. A final full-page scaled orthographic sketch showing minimum dimensions and an isometric view as previously practiced
ideas

Investigation/Ideas:

A design process is what engineers, entrepreneurial, inventors, etc. use or go through to come up with great solutions to resolve or find solutions to problems. Some starting points to coming up with ideas are:

  • Use your own experiences, knowledge, and interests
  • Talk to your peers, friends, and/or professionals
  • Research using Internet, related magazines/books, and/or similar sources
  • Actual ideas already completed that you could use to make it your own

There are many design process models out there, some very long and detailed wile others simple and short. Most successful corporations will already have a process that employees must follow while working which involves reporting on those steps taken. We will look at some of these models and focus in on one specifically called SPICE to show how the technical design process works and also below are some more support links on thumbnail sketching:

Lnks
Samples of Work

The following samples show what thumbnails would look like and how your orthographic sketches would look like when applied to other designs such as key ring accessory project.

Sample Thumbnails

Thumbnails

Sample Ortho 1

Ortho 1

Sample Ortho 2

Ortho 2-3D CAD

Ortho Sketch sample 2

Ortho 3 - 3D Print

Create/Construct:


steps


Create and Construct General Information

This is the section called Create/Construct step, which if you have understood the SPICE design model process from the investigation/ideas section, is the part of the process where you select your best idea and and create a solution based on the problem/challenge. With all activities we use this section or step (of the SPICE design process), to give you the actual steps that are recommended to take, to accomplish what you need to do to complete the project, task and/or goal. For this key ring accessory design and build (3D print) here are the steps you will take:

Actual Steps You Will Take To Complete This Activity (Key Ring Accessory)
  1. Using the handout SPICE Applied to the Key Ring Accessory, fill in each of the steps, using your understanding and the information on this site (once peer take-up is done, instructor will review student samples with you)
  2. Research your ideas on some ideas you can create to later 3D print
  3. Use a full page with large isometric thumbnails to show your designs based on requirements showing hole location and labeled with notation if necessary
  4. Once you have completed your investigation and have many ideas, you will select your best idea and...
  5. Draw a scaled (i.e. to fill the page with space for dimensions) orthographic showing correct front, top, and right side view similar to the ortho 1 sample above (ortho 2 and 3 are samples of what junior grades have accomplished) with dimensions and an isometric

Evaluation:

You will be evaluated on your SPICE key ring accessory explanation, thumbnails, and final orthographic design. Here are some student samples to check out that show some teacher feedback and marks in PDF PDF format: KRA final ortho. A breakdown of those marks are below:

Target
Evaluation Breakdown Component Descriptions Marks
Always double check that you have completed all components for full marks.
SPICE - SPICE design process steps based on the key ring accessory 14
Thumbnails - Five ISO thumbnails, full page with holes, notations, and labels 15
Orthographic - sketch showing final design with 3 views, dimensions, and isometric 20