Introduction to Engineering Introduction to Isometric Ellipse Agenda: Sketching of ellipse for isometric drawings Introduce concepts and conventions of multi-view projections Reference: IGCE, Chap 2: 2.4.2

Recall – Before starting Bike Lab 1 we developed an approach to doing an isometric projection Today - Build on that base and learn how to do circular features (holes and cylinders) in an isometric projection

Review Sketch an isometric of this object Start with a block with dimension W,H,D “Cut away” material you don’t need D H W

Isometric ellipses In an isometric drawing, the object is viewed at an angle, which makes circles appear as ellipses. Holes Cylinders

Ellipses can be in any of three planes

Sketching an Isometric of a Hollow Pipe

Step 1 - Creating the Base Box Diameter Length

Step 2 – Ellipse on Front Face Lines to Tangent Points - lines to tangent points - corner to corner to get center Tangent Points

Step 3 – Ellipse on Front Face Tangent Points Sketch in Arcs

Step 3 – Ellipse on Back Face and Profile Draw Tangent Lines for Profile Complete Visible Part of Back Ellipse Repeat for ellipse on rear face

Step 4 – Ellipse for Hole on Front Face Create Box for Hole Sketch Ellipse

Isometric of Hollow Pipe

Example

Assignment #3: Isometric Sketch Complete the isometric sketch of the object below: