Mr. Tanaka

 Why are engineering drawings important?  What kinds of drawings are most useful to engineers and why?

 You 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.

 I have the blocks that arranged on weekend.  With your block, position your block in the way that is drawn.  You won’t be able to make the one I have!

 There are six sides on the drawing below

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

 The 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.

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 ___: ___.

 A 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?

 Car 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.

 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.

 If 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?

 Orthographic drawing  Oblique drawing  Isometric drawing  Perspective drawing

 Orthographic drawings show the top, sides, and the bottom of an object.

 Isometric 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.

 show 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.

 Show 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

 Like 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 don’t like them. Why do you think that they prefer isometric and orthographic, but not perspective??

 Isometric and orthographic drawings are used for manufacturing drawings.  Why do you think that is?

 Step 1: Front View  Step 2: Top View  Step 3: Right-side View  Step 4: Confirm Measurements  Step 5: Erase the construction lines  Step 6: Dimensions and labels

 To Do’s Make something with blocks Make the isometric drawing of the blocks Make the orthographic drawing of the blocks  Grade Completion: 60% Complexity: 20% Neatness: 20%

 Complete all steps Step 1: Front View Step 2: Top View Step 3: Right-side View Step 4: Confirm Measurements Step 5: Erase the construction lines Step 6: Dimensions and labels

 Make it as complicated as you can Very complicated: 20% Complicated: 15% Kind of complicated: 10% Not very complicated: 5%

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