12.4.5 Irregular Shapes Some cabinet styles have irregularly shaped parts. For example, Early American furniture has many curves. Working drawings usually include patterns that show how to lay out the shape. Patterns Drawings may provide full, half, or detail pat- terns, Figure 12-33. A half pattern shows detail on one side of a centerline. You mark around the pattern, then turn it over and mark again. A detail pattern may be necessary for more complex shaped parts. A square grid pattern is a way to transfer com- plex designs from working drawings to material. Make two square grid patterns. One pattern is traced over the working drawing and the other is a full- size pattern. The size of grids should correspond to the scale of the working drawing. If the scale is 1/4″ equals 1″, use a 1/4″ grid sheet. The full-size transfer pattern will be 1″ squares. Goodheart-Willcox Publisher Figure 12-30. Hexagon layout made by striking arcs with a pair of dividers. Goodheart-Willcox Publisher Figure 12-31. Octagon layout using a divider or compass. Goodheart-Willcox Publisher Figure 12-32. An ellipse for an oval tabletop can be easily laid out within a rectangle. Radius of Circle A C D B 48 28 39 19 1/2 19 1/2 B E C H D F A G O I J 8. Tie a string tightly around the thumbtacks. 9. Remove the thumbtack at point E. 10. Place a pencil inside the string loop and pull the loop tight. Move the pencil to create the ellipse. For accuracy, keep the string at the same point on the pencil while moving about the ellipse. Laying Out an Ellipses with a String An ellipse (oval) can be laid out easily with a string, Figure 12-32. Select a string that will not stretch, and proceed as follows: 1. Cut out a rectangle the desired size of the ellipse. 2. Make centerlines EF and GH. 3. Make an arc using point B as the pivot and line BC as the radius. 4. Measure the length of line AD. 5. Divide that distance by two. (AD/2) 6. Measure this distance on each side of O to locate points I and J. 7. Put thumbtacks or small nails at points E, I, and J. Procedure 162 Section 2 Design and Layout Copyright Goodheart-Willcox Co., Inc.