TECH 104 – Technical Graphics Communication Week 6: Section Views

TECH 104 – Technical Graphics Communication Here’s what we talked about last time….. Week 6: Section Views

TECH 104 – Technical Graphics Communication We can also use the glass box technique to add an additional Picture Plane (PP) to project inclined surfaces to. By doing so, we can show the slanted surface’s true shape and size. NOTE: The new glass plane is parallel to the surface it describes just like the other glass projection planes. Week 6: Section Views

TECH 104 – Technical Graphics Communication Here’s how to lay out an auxiliary view: Step 1: Make a new PP line labeled “1” that is parallel to Line AD in the FRONT view. This PP may be placed any distance from the object you wish. Week 6: Section Views

TECH 104 – Technical Graphics Communication Step 2: Add the other PP lines as shown so they will connect to PP 1. It is always a good idea to label the PPs as shown. Week 6: Section Views

TECH 104 – Technical Graphics Communication Step 3: Project the end points of Line AD at a 90 degree angle from the front view. Week 6: Section Views

TECH 104 – Technical Graphics Communication Step 4: Transfer the distance from PP to point C in the TOP view… …to its new position from PP 1 in the auxiliary view. Week 6: Section Views

TECH 104 – Technical Graphics Communication Step 5: Connect the new point C with the projected line to find point B. Do the same thing for points A and D. Week 6: Section Views

TECH 104 – Technical Graphics Communication Step 6: Snap your lines in the auxiliary view to create its final form. NOTE: You do not need to label all points on your drawing. Week 6: Section Views

TECH 104 – Technical Graphics Communication Let’s now take a look at how we can show hidden information using section views….. Week 6: Section Views

TECH 104 – Technical Graphics Communication Section views are used to expose hidden features. When we “open up” an object and view interior features, we see them not as hidden lines, but as object lines. Week 6: Section Views

TECH 104 – Technical Graphics Communication The “Cutting Plane” is a flat surface that identifies: Which section of the object is to be shown, and 2. The path of the imaginary cut through the object Week 6: Section Views

TECH 104 – Technical Graphics Communication Figure A illustrates the proper technique that should be used to show a section view A correctly drawn section view which uses both object and section lines. An improperly drawn section view where the hidden lines have not been replaced with object lines. C. A normal multiview projection of the part. Week 6: Section Views

TECH 104 – Technical Graphics Communication The Cutting Plane Line: Is used to show where the object is being cut Shows the Line of Sight (LOS) so a proper section view can be drawn. Replaces the need to draw an entire cut-ting plane Why is the example shown on the right incorrect?? Week 6: Section Views

TECH 104 – Technical Graphics Communication Cutting Plane lines are the heaviest of all lines used in drafting. They are drawn much like center lines, but have 2 short dashes in them. The arrows on their end show the line of sight. Week 6: Section Views

TECH 104 – Technical Graphics Communication Every material has a “hatch line “ pattern. Cast Iron can be used as the generic hatch line for any material. If you use this symbol, a “general note” should be added to the plate to identify the proper material used in the part. Week 6: Section Views

TECH 104 – Technical Graphics Communication Please review images 14.20 through 14.23 to review how hatch lines are drawn in diverse applications. Here are some general rules: Hatch lines should never be drawn parallel to the edge of an object. Always use a slightly different angle so it makes the object easier to read. 2. If you have large interior areas to hatch, using short hatch lines around the perimeter is an acceptable practice. 3. If there needs to be notes or dimensions placed inside a hatched area, leave “white space” in the center of the hatch area to add these items. Week 6: Section Views

TECH 104 – Technical Graphics Communication The full section is the most common type of section view used. It is known as a “FULL” section because the cutting plane passes through the full length of the object. Week 6: Section Views

TECH 104 – Technical Graphics Communication “Half” sections show the interior of an object where the cutting plane has penetrated only half way through the object. NOTE: The cutting plane line may only have one arrow on it. Week 6: Section Views

TECH 104 – Technical Graphics Communication “Broken” sections have no cutting plane line and are used to show a small, localized area of the object. Week 6: Section Views

TECH 104 – Technical Graphics Communication “Revolved” section views are used to show diverse shapes that may appear in a part. Here we see that the section lies on the area it describes and may be placed on top of object lines, or be shown as part of a broken out section to assist whoever is reading the plate. Week 6: Section Views

TECH 104 – Technical Graphics Communication “Removed” sections allow the sectional view to be placed in another area of the plate so as not to crowd other views. All removed views are labeled on their cutting plane and the view. Week 6: Section Views

TECH 104 – Technical Graphics Communication “Offset” sections use a cutting plane that jogs to pick up valuable features of the part. Week 6: Section Views

TECH 104 – Technical Graphics Communication Sectioned assemblies are used to show relationships between parts. NOTE: The hatching lines alternate direction on parts that are adjacent to one another. Week 6: Section Views

TECH 104 – Technical Graphics Communication Drawing styles may sometimes be combined with one another. Here we see an auxiliary and section view combined. Week 6: Section Views

TECH 104 – Technical Graphics Communication Examples of sectioning conventions... Week 6: Section Views

TECH 104 – Technical Graphics Communication Examples of sectioning conventions... Week 6: Section Views

TECH 104 – Technical Graphics Communication Examples of sectioning conventions... Week 6: Section Views

TECH 104 – Technical Graphics Communication Examples of sectioning conventions... Week 6: Section Views

TECH 104 – Technical Graphics Communication Examples of sectioning conventions... Week 6: Section Views

TECH 104 – Technical Graphics Communication Week 7: Dimensioning