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Day 1
Why do we need technical drawing?
(This video is old, take it with a grain of salt)
So what about us- as new engineers?
And how do we get the skills to be really good at technical drawing?
What is Orthographic Drawing?
Sometimes called orthogonal projection, it is a means of representing three-dimensional objects in two dimensions (flat space), by showing every plane (side) of the object.
In industry, a machinist needs to use clear and accurate drawings so that (s)he can manufacture parts correctly. The drawings must be drawn to scale to show the exact height, width and depth of the object. Orthographic Projections are also called 3-view or multi-view drawings. The finished drawing has three views of the same object. The front view is drawn in the lower left area of the paper, the top view is drawn above, and the Right Side view is drawn to the right.
Imagine that you are holding the object in front of you so that you see only the front view. When you are looking at the front view, you see the height and width of the object; you do not see the depth of the object. The front view of the object is drawn as though you are looking directly at only the front of the object.
Now imagine you rotate the object in your hand and you are now looking at only the top of the object. The top view is drawn directly above the front view.
And imagine you now rotate the object in your hand and you are now looking at only the right side view of the object. The right side view is drawn directly to the right of the front view of the object.
An orthographic drawing also has the dimensions of the object drawn neatly so the machinest knows exactally how to measure the object as (s)he manufactures the product.
VIEWS: Objects drawn orthographicly have 3 views. They are:
Front- the longest side that ALSO give us the most visual information
Side- the view to the right of the front side
Plan- the view of the top of the object
Class practice- answer the following questions for the image below:
Question 1: Which view is the FRONT view? How do you know?
Question 2: Which view is the PLAN/TOP view? How do you know?
Question 3: Which view is the SIDE view? How do you know?
Let's practice! Click the following links to work on orthographic plane visualization:
DAY 3
Dimensioning: The numerical units of an object.
As a general guideline to dimensioning, try to think that you would make an object and dimension it in the most useful way. Put in exactly as many dimensions as are necessary for the craftsperson to make it -no more, no less. Do not put in redundant dimensions.
Repeatedly measuring from one point to another will lead to inaccuracies. It is often better to measure from one end to various points. This gives the dimensions a reference standard.
This takes patience, practice, and mathematics!
As a class, solve to find all the missing units of the figure below:
Object Measurement Practice Worksheet (Engineering 1 basket)
Day 4
Transitioning...
ISOMETRIC DRAWING
What is Isometric Drawing?
Isometric drawings are 3-dimensional. They show three sides, all in dimensional proportion, but none are shown as a true shape with 90 degree corners. All the vertical lines are drawn vertically but all horizontal lines are drawn at 30 degrees to the base line.Isometric is an easy method of drawing 3D images.
The isometric projection is the basis for the typical three-dimensional engineering sketch. The proportions along each axis are in the ratio 1:1:1. The term Isometric means equal (iso) angles and length (metric). Circles on the isometric planes appear as ellipses in isometric sketches. Isometric grid paper is a convenient aid in sketching isometric drawings with both straight edges and circular features.
X Axis- show the WIDTH of an object; they correspond to the FRONT view and the PLAN view.
Y Axis- show the HEIGHT of an object; they correspond to the FRONT view and the SIDE view.
Z Axis- show the DEPTH of an object; they correspond to the SIDE view and the PLAN view.
Using Orthographic views to draw Isometric images (video) - practice with your iso graph paper!
DAY 5
** REMINDER: What to know about Isometric Drawing **
The above video has ALL of the steps laid out to create an iso drawing from ortho views.
Drawing Practice: Isometric Drawings (video)
Using the isometric dot/grid paper (in the Engineering 1 basket) and your ruler to measure, practice drawing 3D printed forms.
x= width y= height z= depth
Figure 1: x- 6 units, y- 4 units, z- 1 unit
Figure 2: x- 7 units, y- 6 units, z- 5 units
Practice Worksheets: Pick up a packet from the basket- this becomes HW if you do not finish it!
Practice, practice, practice!...
Until eventually, you have this:
SKIP FOR 2019-2020
Final Technical Drawing Project:
Your Name/ Word (*7 letters or more*)
You will need to creat your name in isographic lettering, fully colored in (nicely!), and turned in. Watch the following video with Lettering to give yourself a better idea.
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