Introduction to Engineering Reading Working Drawings Agenda Introduction to reading and developing a basic set of working drawings Working Drawings

Mechanical Working Drawings Working drawings are the complete set of drawings specifying the manufacture and assembly of a product. Generally consists of multiple drawings, on multiple sheets. May contain written instructions called specifications. Working Drawings

Contents of a Set of Working Drawings 1. Detail drawings of each nonstandard part. Usually one part per “sheet”. 2. An assembly drawing (or subassembly drawings) showing how the parts fit together. 3. A bill of materials (BOM). This is essentially a parts list. It is often with the assembly drawing. 4. A title block on each sheet. Working Drawings

Reading Working Drawings Our first goal is to learn how to read a set of working drawings. Example: simple fingernail clipper Working Drawings

Example 1 - Assembly Drawing Things to note: This will be one of two assembly drawings in the set. Function is to show how all the parts go together. In some cases might have overall dimensions or other specifications on this sheet. Note title block - indicates this is one of 8 drawings in the set. - tell who, what, when and where of part Working Drawings

Full Section View Second type of assembly drawing. Ask what this one shows or shows better than the first one. - how rivet fits in. - how pin fits through Working Drawings

Detailed Part Drawing: Rivet Example individual part diagram. Note that isometric is not standard. Why only two orthographic views? Might note General Note on Tolerance but one dimension is toleranced tighter. Likely why? Working Drawings

Detailed Part Drawing: Bottom Clipper Another of the parts. If we showed them all, how many individual part diagrams would there be? 6 Working Drawings

Example 2 - Butterfly Valve This is one of the examples at the end of Chapter in GCE. Questions to ask students that can be answered by this drawing are: What parts of the “Working Drawing Set” are show here? Assembly drawing and Bill of Materials How many and what types of assembly drawings are shown on this sheet? isometric (top left) exploded (center) half sectioned isometric 3) How many ITEMS or different types of parts are included? 9 Note that they are nu7mbered in both the exploded and sectioned assemblies. 4) How many total parts (included multiples) are used in this assembly? 12 5) How many different “threads per inch” are used on various parts of this assembly? 3 24, 32 and 48 threads per inch Which Items would likely be purchased rather than manufactured specifically for this assembly? Items 2, 5, 7, & 9 Working Drawings

Individual Part Drawing Assembly would generally be followed by part diagrams. One part per sheet for each non-standard part. Non-standard usually means custom for this assembly, not purchased off the shelf. One part per sheet so that they can be manufactured independently with no confusion. Enough detail must be given that someone can pick up the drawing and build the part. Basic dimensions and tolerances Type of material (may be in title block or notes) Type of finishes or other special instructions. Working Drawings

In-Class Exercise Teams answer questions on Worksheet 1 Working Drawings

Assignment DWG 9 – Working Drawing Worksheet Working Drawings