Engineering Drawing

Engineering DrawingMr. TanakaFocus QuestionsWhy are engineering drawings important?What kinds of drawings are most useful to engineers and why?ObjectivesYou will be able to:Explain why engineers use precise drawing methods;Recognized the difference between isometric and orthographic drawings; and Make orthographic and isometric drawings of simple objects.Drawing exerciseI have the blocks that arranged on weekend.With your block, position your block in the way that is drawn.You wont be able to make the one I have!

Viewing an objectThere are six sides on the drawing below

Understanding scaleIf an object is too large or too small to draw on a piece of paper, a drawing can be scaled down or up.

12 inches =12=1The scale for the L-shaped box is 1/2 or 1:2.It means that the drawing is a half of actual size.Question: How long should 3 side of the object be in this drawing?What would the scale on the drawing be if you wanted to make it three times bigger than the actual object.Practice!What is the scale if a 4-inch length on the drawing corresponds to a 4-foot length on the actual objects?

Scale: ___ in.: ___in. or ___: ___.Practice, PracticeA building has a wall of windows that is 12 feet across. If a scale of 1:24 is used, how wide is the wall of windows on the drawing, in inches?Practice, practice, practiceCar designers build models of new designs because, unlike a drawing, a model can be seen from all sides. If you built a 1:10 scale model of a car that is 15 feet long, how long would the model be? Give your answer in inches.Last one!If you are a carpenter following a 1: 20 blueprint for a house and you measure the wall on the blueprint to be 8 inches long, how long should you build the wall for the house? Give your answer in inches.Oh, actually one moreIf you discovered that the architect who made the blueprint made a mistake, and the scale should really have been 1:25, how would you need to change the length of the wall of the house?Four types of drawingsOrthographic drawingOblique drawingIsometric drawingPerspective drawingOrthographic DrawingOrthographic drawings show the top, sides, and the bottom of an object.

Isometric DrawingIsometric drawings show the front, top, and right-side vies.Depth is shown by slanting the edges up at a 30 degree angle from the horizon. This is especially useful to engineers because it shows depth, and each line is drawn to scale.

Oblique Drawingshow the front, top, and one side of an object.The front face of the object is drawn as though you are looking at it from the front. Horizontal edges are drawn back from the front at a 45 degree angle.Lines are NOT drawn to scale.

Perspective DrawingShow objects as they would appear to the naked eye or in a photograph.Lines showing depth converge toward an imaginary vanishing points.This creates the appearance of distance

Artists and architectsLike oblique and perspective drawings because they make it easy to picture what buildings and other three-dimensional objects look like in the real world.Engineers dont like them. Why do you think that they prefer isometric and orthographic, but not perspective??Isometric and OrthographicIsometric and orthographic drawings are used for manufacturing drawings. Why do you think that is?Lets Try It!!Step 1: Front ViewStep 2: Top ViewStep 3: Right-side ViewStep 4: Confirm MeasurementsStep 5: Erase the construction linesStep 6: Dimensions and labelsIsometric Orthographic

Orthographic Isometric

Project 1: Engineering DrawingTo Dos Make something with blocksMake the isometric drawing of the blocksMake the orthographic drawing of the blocksGradeCompletion: 60%Complexity: 20% Neatness: 20%

CompletionComplete all stepsStep 1: Front ViewStep 2: Top ViewStep 3: Right-side ViewStep 4: Confirm MeasurementsStep 5: Erase the construction linesStep 6: Dimensions and labels

ComplexityMake it as complicated as you canVery complicated: 20%Complicated: 15%Kind of complicated: 10%Not very complicated: 5%

NeatnessDraw all lines with rulers! Very neat: 20%Neat: 15%Kind of neat: 10%Not very neat: 5%