Copyright © Texas Education Agency, 2012. All rights reserved. Reading Drawings Copyright © Texas Education Agency, 2012. All rights reserved.  

Why Have a Plan or Blueprint? There are different types of plans or blueprints to allow the viewer different visual clues for producing the products. Drawings are used to make the parts. The drawing standards have been set for ease of understanding and producing the part. There are different types of lines used to draw a blueprint or a plan. Copyright © Texas Education Agency, 2012. All rights reserved.  

Copyright © Texas Education Agency, 2012. All rights reserved. Machined Toy Top 1 dia. 2.75 1.50 .75 .25 dia. The machined toy top is dimensioned in decimals. It shows two views: a front view and a right side view. Ask the students what size piece of aluminum material will be needed to be cut to make their top. Copyright © Texas Education Agency, 2012. All rights reserved.  

Copyright © Texas Education Agency, 2012. All rights reserved. Types of Drawings Copyright © Texas Education Agency, 2012. All rights reserved.  

Three View Drawing or Working Drawing 3 1 1 1/2 2 1/2 1 3/4 The three view drawing or working drawing shows the object from three sides. These views will show the shape of the object and location of any cutouts or holes. The dimensions are usually added to this type of plan. Copyright © Texas Education Agency, 2012. All rights reserved.  

Copyright © Texas Education Agency, 2012. All rights reserved. Oblique Drawing The oblique drawing is a pictorial drawing showing the shape of the object. The drawing is drawn as a front view, then the depth is projected from the corners at an angle. There are no dimensions or hidden lines on an oblique drawing. Copyright © Texas Education Agency, 2012. All rights reserved.  

Copyright © Texas Education Agency, 2012. All rights reserved. Isometric Drawing The isometric drawing is drawn at a 30degree angle for the front and the side. This gives a 3D effect to the drawing. There are no dimensions or hidden lines on an isometric drawing. Copyright © Texas Education Agency, 2012. All rights reserved.  

Copyright © Texas Education Agency, 2012. All rights reserved. Exploded View Drawing This drawing shows how parts in an assembly fit together. Copyright © Texas Education Agency, 2012. All rights reserved.  

Sectional View Drawing The sectional view is a drawing with a part removed or cut out to show the internal parts of the part. Copyright © Texas Education Agency, 2012. All rights reserved.  

Sheet Metal Development Drawing This drawing shows a box or other sheet metal project in a flat view. It allows the project to be laid out on metal, cut and folded in the finished product. Copyright © Texas Education Agency, 2012. All rights reserved.  

Copyright © Texas Education Agency, 2012. All rights reserved. Welding Plans . The welding drawings describe how the weld joints are to be produced. Copyright © Texas Education Agency, 2012. All rights reserved.  

Copyright © Texas Education Agency, 2012. All rights reserved. Drawing a Plan Copyright © Texas Education Agency, 2012. All rights reserved.  

Copyright © Texas Education Agency, 2012. All rights reserved. Drawing a Plan Only necessary views are drawn. They show shape, location and size. The front view shows the most detail. Dimensions are in between views if possible. Other views may be added for clarification. Copyright © Texas Education Agency, 2012. All rights reserved.  

Copyright © Texas Education Agency, 2012. All rights reserved. Drawing Projection A glass box is unfolded showing all sides of the project. Fig. 257 All Planes Are Revolved until they Coincide with the Front Plane Fig. 256 Revolution of the Planes of Projections. Copyright © Texas Education Agency, 2012. All rights reserved.  

Copyright © Texas Education Agency, 2012. All rights reserved. Six Views of an Object Copyright © Texas Education Agency, 2012. All rights reserved.  

Necessary Views of a Drawing The three views in black are the necessary views: front, top, and right side. The three views in red are mirror images of the black views and show the details as hidden lines. Copyright © Texas Education Agency, 2012. All rights reserved.  

Dimensions on a Drawing 3 Dimensioning each view makes the drawing too difficult to understand. The dimensions are placed on the drawing only once. 1 1 ½ 1 ½ 1 ½ 1 ½ 1 1 1 2 2 1 1 3 Copyright © Texas Education Agency, 2012. All rights reserved.  

Correct Placement of Dimensions 1 ½ 3 1 2 1 Copyright © Texas Education Agency, 2012. All rights reserved.  

Types of Lines on a Blueprint What are all the arrows pointing to? What do dashed lines mean? Have students attempt to answer the questions. Copyright © Texas Education Agency, 2012. All rights reserved.  

Copyright © Texas Education Agency, 2012. All rights reserved. Line Symbol Definition Object Solid black line showing the shape of an object Hidden Dashed line as dark as the object line shows shapes covered by other parts. For example, depth of a hole, etc. Center Line with a dash in the middle or a plus with lines radiating from it shows where the center is located. Section Line that has long and short sections with arrows pointed out shows the inside of a part by cutting out a section. Fold Line with 2 X’s show where to fold a sheet metal development. Extension A thin line extending from the edge to the dimension line indicates the dimension. Dimension Thin lines pointing to the extension lines show the measurement. + X X 2 Copyright © Texas Education Agency, 2012. All rights reserved.  

Copyright © Texas Education Agency, 2012. All rights reserved. Plan Dimensions Measurements are in inches or mm. Dimensions have three parts: extension lines, arrows and the number. The largest measurements are on the outside of the set of dimensions. Dimension arrows 6 1/4 Dimension number Extension lines Copyright © Texas Education Agency, 2012. All rights reserved.  

Copyright © Texas Education Agency, 2012. All rights reserved. Examples of Plans Fig. 304. Draw views with instruments; add missing lines. Layout 3D (Appendix I). Copyright © Texas Education Agency, 2012. All rights reserved.  

Copyright © Texas Education Agency, 2012. All rights reserved. Worm Saddle Plans 3 1 1/2 7/8 2 7/8 2 7/8 2 Dia. 7/8 DRILL 7 1/2 1/4 ½ DRILL 2 HOLES What is the length of the piece of metal this part is made from? 7 ½” What is the thickness of the worm saddle? ¾ “ What size block on metal will it take machine the part? 7 1/2” X 3” X 3” How many holes are drilled in the worm saddle? 3 (2) ½ drills and (1) 7/8 drill Can you sketch a drawing of the worm saddle on graph paper? 3 3/4 2 1/2 2 1/2 WORM SADDLE Copyright © Texas Education Agency, 2012. All rights reserved.  

Reading a Basic Drawing 1 1/2 1/2 2 1/2 4 1/2 DRILL 4 HOLES 1 R 3/4 R 1 2 What is the total length of the part? What is the total height of the part? Explain the dashed lines on the drawing? The drawing is an adjuster base. The total length is figured by taking the 4 inch measurement from the back of the block to the center of the 1” radius and adding the radius dimension 4” + 1” = 5” The total height is done the same way the distance from the bottom of the part to the center of the ¾” radius and then adding then radius dimension 1 ½” + ¾” = 2 ¼” The dashed lines are the edges of the 4 holes drilled in the part. The dashed lines show that the holes are located in the view but are hidden inside the part. Copyright © Texas Education Agency, 2012. All rights reserved.  

Copyright © Texas Education Agency, 2012. All rights reserved. Hammer Drawings 1/2” ROUND 3 1/4-20 THREADS 3/4” DEEP HAMMER HANDLE 3/4 SQUARE 2 1/2 1 1/8 3/8 1/4-20 THREADS 3/4” DEEP 6 HAMMER HEAD 1/4” ROUND 1/4-20 THREADS x ¾ LENGTH BOTH ENDS This slide shows the three pieces of the hammer. The information on the three drawings are enough to make the parts. HAMMER SHANK Copyright © Texas Education Agency, 2012. All rights reserved.  

Exploded View of Hammer The exploded view shows how to assemble the hammer. Copyright © Texas Education Agency, 2012. All rights reserved.  

Sheet Metal Development Cylinder Prism The graphic shows some of the different types of sheet metal development. The following slides will show how to read and draw simple sheet metal development drawings or plans. Cone Pyramid Fig. 568 Development of Surfaces Copyright © Texas Education Agency, 2012. All rights reserved.  

Sheet Metal Layout Drawings The layout is a flat drawing with cut and fold lines drawn. These lines are used to form (develop) the 3D shape. Drawings have tabs, folds, and hems shown. Copyright © Texas Education Agency, 2012. All rights reserved.  

Copyright © Texas Education Agency, 2012. All rights reserved. Sheet Metal Box Plans 8 1/2 5 1/4 Hems All Around 11 1 45° X Hem Fold Hems fold over the edges so it is not sharp and the edge is strengthened. Folds are marked to allow for bending the shape. Copyright © Texas Education Agency, 2012. All rights reserved.  

Sheet Metal Layout Plans 2 3 5 Copyright © Texas Education Agency, 2012. All rights reserved.  

Sheet Metal Layout Plans Or Development 10 1/2 2 1 ALL HEMS 1/4” 3 7 1/2 X Copyright © Texas Education Agency, 2012. All rights reserved.