Machine Drafting Board (IL-IRD) Archetecture & Construction

State Only Contest

Technical Standard

Purpose: To evaluate each contestant's preparation for employment and to recognize outstanding students for excellence and professionalism in the field of machine drafting.

Clothing Requirement: Business attire recommended, no T-shirts or jeans.

Eligibility: Open to active SkillsUSA members enrolled in programs with machine drafting as the occupational objective.

Equipment and Materials: Supplied by the Technical Committee: • Drafting tables, drafting machines or parallel ruling units for each contestant • Drafting paper, polyester film (Mylar) and sepia as required • Reproduction equipment • Technical pens, ink and supplies • All necessary information and furnishings for judges and technical committee

Supplied by the Contestant: • Drafting board with T-, drafting machine, or parallel rule to support “C” size (18” x 24”) paper • White backing paper (if needed) • Non-electric eraser • Lead pointer or pencil sharpener • 4H, 2H, H, and HB grade pencils or leads with lead holders • • Pocket calculator (non-graphic or formula memory) • Decimal/fraction/metric equivalent chart • 45-90 degree triangle (10 inch) • 30-60-90 degree triangle (10 inch) • Mechanical engineer’s scale • Metric scale • Erasing shield • set

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• Drafting brush • Circle template up to 3” • Ellipse template up to 2” • Drafting tape • Dry cleaning pad, powder or dust bag • One-page, typewritten résumé

To insure that all competitors have a fair and equal opportunity to compete, please adhere to the above list before entering the contest area.

Scope of Contest 1. Contestants will demonstrate their ability to perform jobs or skills selected from the following list of competencies as determined by the State Technical Committee. a. Scale Usage i. Read the mechanical engineer’s scale ii. Read the metric scale b. Sketching i. Prepare proportional design sketches ii. Make freehand sketches iii. Sketch oblique views iv. Sketch isometric pictorial views v. Sketch various geometric forms c. Orthographic Views and Geometric Constructions i. Construct various geometric forms using instruments ii. Construct various orthographic views in first angle projection iii. Construct isometric pictorial views iv. Construct oblique views v. Draw various perspective views d. Basic Tolerancing i. Interpret decimal tolerance dimensions ii. Calculate and assign tolerances to mating parts using standard fit tables iii. Construct a using datum dimensioning e. Inking Tools and Techniques i. Draw and erase ink lines on vellum or tracing cloth ii. Draw and erase ink lines on polyester film iii. Complete steps in inking a drawing or a tracing iv. Fill clean technical and pocket model pens f. Auxiliary Views i. Label points and planes of a three-view drawing ii. Construct a primary auxiliary of an inclined plane iii. Construct a true size auxiliary of a curved surface iv. Construct true length of an oblique line v. Determine the true angle and slope of a line vi. Determine the true angle between two planes

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vii. Determine visibility of crossing skew lines in space viii. Determine the visibility of a line and a plane that cross in space ix. Locate piercing point of a line and plane x. Construct a secondary auxiliary view of an object xi. Construct point view of a line xii. Determine true angle between two planes in a secondary auxiliary xiii. Construct a true size auxiliary of an oblique plane xiv. Determine shortest distance between a point and a line xv. Determine shortest distance between two skew lines g. Sectional Views i. Construct various material symbols in section ii. Construct a full section of an object iii. Construct a half-section of an object iv. Construct an offset section of an object v. Construct a broken-out section of an object vi. Construct a removed section of an object vii. Construct a revolved section of an object viii. Construct a rib section of an object ix. Construct an aligned section of an object with holes, ribs or spokes x. Construct adjacent parts in assembly section xi. Construct conventional breaks h. Tools and Equipment i. Read settings ii. Read venier iii. Measure with scales iv. Compute technical drafting problems using a calculator v. Use a micrometer vi. Use a venier caliper i. Reference Materials i. Determine manufacturer of mechanical components from Thomas Register ii. Write a letter requesting product literature for mechanical components iii. Write a technical report using reference material j. Layouts and Working i. Draw a design layout ii. Draw a set of detail drawings iii. Draw an assembly drawing iv. Complete a detailed title block and revision block v. Complete a pull list vi. Make a drawing revision k. Dimensioning and Tolerancing i. Dimension an object completely ii. Calculate and dimension clearance fit tolerances using standard fit tables.

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iii. Calculate and dimension interference fit tolerances using standard fit tables iv. Calculate and dimension interference fit tolerances mating parts using standard fit tables v. Calculate and dimension hole size limits for standard dowels vi. Dimension an object using position and form tolerances vii. Determine ranges of motion of limbs and spaces required for a person l. Fasteners and Hardware i. Construct thread symbols ii. Construct bolts, screws and nuts iii. Construct an assembly containing various fasteners iv. Construct a welded assembly drawing v. Construct spring drawings to include specifications vi. Construct keys in assembled positions vii. Write specifications for hardware from vendor catalog m. Presentation Drawings i. Shade pictorials ii. Construct an oblique presentation drawing iii. Construct a two point presentation perspective of an object iv. Construct an exploded assembly presentation drawing n. Materials and Specifications i. Determine wire and sheet metal size from gage number ii. Select materials from a materials stock book o. Manufacturing Processes i. Calculate bend allowance for sheet metal ii. Design a casting part iii. Design a forging part iv. Design a welded part v. Design a thermoplastic part p. Sheet Metal Developments i. Label points, lines, and planes in views ii. Identify true lengths and types of lines iii. Identify true sizes and types of planes iv. Construct lengths of lines and true sizes of planes using auxiliary views v. Construct true lengths of lines by rotation vi. Construct true sizes of planes by rotation vii. Locate elements of single curved surfaces viii. Construct intersections of surfaces ix. Construct intersections of surfaces using two-view method x. Construct radial line developments xi. Construct parallel line developments xii. Construct special developments q. Power Transmission i. Construct a spur gear drawing

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ii. Construct a bevel gear iii. Construct a worm and worm gear iv. Calculate gear ratios v. Determine gear rotation vi. Calculate gear speed vii. Construct a cam drawing viii. Select a chain drive ix. Select a V-Belt drive x. Select types of bearings from handbooks

2. Preparation of drawings will include proper scaling and tolerancing.

3. Rating of problems will be done from reproduced copy; however, judges will observe the entire contest.

4. All lettering will be freehand. Drafting media will consist of paper, mylar (polyester film) or sepia.

5. Finished work will be done with ink or pencil and appropriate material as directed by the technical committee.

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