Module 6: Drafting

Drafting

In this module:

You will learn how to communicate 3d shapes on 2d paper. By the end of this module you will be able to:

Define and describe an orthographic projection and identify the 3 main orthographic projection views
Identify the 2 dimensional shape that represents the orthographic projection of standard geometric solid
Create orthographic projections of geometric solids
Create an orthographic projection of a building brick including labels, dimensions, and hidden edges

To complete this module you will need:

📝📝📝📝📝 The 5 worksheet pages for Module 6
✏️Sharp or mechanical pencil
✂️Scissors
📏Straight edge or ruler
🟥🟦2 different 3d printed bricks (Download to print your own or ask your teacher for them)
🟧 Glue Stick

How do we get to 3D?

Soon, you're going to be sending your designs out to the 3d printer farm for your first prototypes. But how do we use a 2D medium such as drawing to communicate a 3d shape?

That's where orthographic drawings come in!

ORTHOGRAPHIC PROJECTIONS are highly precise drawings that tell all the dimensional information of a 3d object. Complete orthographic drawings will typically have at minimum, a front, side, and top view, but if those views aren't enough to fully communicate the shape, other views such as bottom, back or cross-sections may be included.

A single view of the orthographic projection, such as just the top view, is called a SINGLE VIEW DRAWING. When all the single view drawings are lined up together on a page, they become an orthographic projection.

But what are orthographic projections?

The single view drawing is just the straight on view at a certain angle. If, for instance, we're going to create the front view of a cylinder, We would look just straight forward at the cylinder and draw JUST what we see. If we're looking at the front, we can't see the top, can't see the bottom, just the face that wraps around. That face no longer looks curved, its just a flat rectangle.

The front projection of a cylinder is a rectangle.

Create orthographic projections for:

The rest of the Cylinder
Cube
Pyramid
and your choice of Cone, Sphere, or Prism

Make a block, unfold to see the projections

Carefully cut out the shape on the bottom of the worksheet ALONG THE DOTTED LINES. When done, fold along the solid lines between the faces to create a block.

When we unfold the block, we see the single view projections of each side. This is the same layout we use when combining our single views into an orthographic projection.

Creating an Orthographic Projection

To create an orthographic projection, we need to be precise. It is important to use a straight edge such as a rule to make sure straight lines are straight. When drawing curves or circles, take your time and draw lightly at first to make sure the shape is right before drawing darker.

Follow along in the video as we make an orthographic projection of a standard 1x2 plate brick.

What about the stuff we can't see, do we just ignore it?

Sometimes!

If there is information that is hard to show in other views, such as the depth or shape of a hole, we might need to include it in the drawing where it normally wouldn't be visible. These important things that we can't see are called HIDDEN EDGES. To not confuse visible and hidden edges, the hidden edges are always drawn with a dashed line. That tells us they're not visible normally, but actually what's happening behind the faces we can see.

Your turn

There are dozens of different building block shapes to choose from, pick a new brick, anyone you'd like, and create an orthographic drawing of it!

Don't forget to take pictures of your orthographic projections so you can use them when you publish your work at the end of the project!

Exit Ticket

Congratulations finishing module 6!

Please fill out the exit ticket.

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