Engineering - Architectural Drawing - Sprocket - AutoCAD Assignment Help

Engineering Assignment Help

• This architectural drawing makes extensive use of both the POLYGON command and the OFFSET command. Drawing Suggestions All radii except the 6? polygon are given from the center point to the midpoint of a side.
• In other words, the 6? polygon is inscribed, whereas all the others are circumscribed. Notice that all polygon radii dimensions are given to the outside of the 2? × 4?.
• Offset to the inside to create the parallel polygon for the inside of the board.
• Create radial studs by drawing a line from the midpoint of one side of a polygon to the midpoint of the side of another, or the midpoint of one to the vertex of another as shown; then, offset 1? each side and erase the original.
• Array around the center point. Trim lines and polygons at vertices. You can make effective use of MIRROR in the elevation.

• This drawing can be done with the tools you now have. It makes use of object snap, TRIM, OFFSET, and polar array. Be sure to set the limits large, as suggested.
• Drawing Suggestions Begin by drawing the 12.25- and 11.25-diameter circles centered on the same point near the middle of your display. To construct the sprocket teeth, draw a line using the Quadrant object snap to locate the point at the top of the 12.25-diameter circle.
• The second point can be straight down so that the line crosses the 11.25-diameter circle. The exact length is insignificant because you will trim the line back to the inner circle. Offset this line .1875 on both sides. Trim the first line, and trim and extend the other two lines to the inner and outer circles. Create a polar array of these lines and trim them to create the teeth.
• Draw the 10.25 B.C. on the Centerline layer. Draw a line from the center to the quadrant. Use grips to rotate and copy the line to 30° and 60° for the 0.75-diameter circles, and 20° and 70° for the inside cutout.
• Draw two circles where the centerline intersects with the bolt circle. Construct a polar array to get the proper hole pattern.
• Draw the 7.44-diameter circle and the 3.25-diameter circle. Trim to construct the cutout geometry. This drawing uses continuous lines, hidden lines, centerlines, and fillets.
• The side view should be quite easy once the front view is drawn. Remember to change layers when you want to change linetypes.
• Drawing Suggestions Study the dimensions carefully and remember that every grid increment is 0.25, and snap points not on the grid are exactly halfway between grid points. The four circles at the corners are 0.38 (actually 0.375 rounded off) over and in from the corner points. This is three snap spaces (0.375 = 3 × 0.125).
• Position the three circles along the centerline of the rectangle carefully. Notice that dimensions are given from the center of the screw holes at top and bottom. Use the circle perimeters to line up the hidden lines on the side view, and the centers to line up the centerlines.