Pattern Development I: Parallel Line
Laying out patterns by parallel line development, followed through a first-year apprentice at a Halifax sheet metal contractor: layout geometry, orthographic views and true lengths, cut prisms and mitred copings, round pipe cut at an angle, two-piece and multi-piece gore elbows, rectangular elbows, tees and laterals, offsets and breeches, seam allowances and notching, and a capstone gore elbow and lateral for a school retrofit.
SMW-120 12 lessons · 2 h 45 min ▶ Video lessons coming soon
Offered by HSM University · Sheet Metal
This is the Canadian version of this course. See the American version.
What you'll learn
- Perform the basic geometric constructions of layout, including perpendiculars, bisectors, equal divisions, polygons and tangent arcs, accurately with layout tools
- Read orthographic views, identify true lengths and true shapes, and draw the elevations, half plans and auxiliary views a pattern needs
- Explain the principle of parallel line development and apply its standard sequence from elevation and plan to a checked net pattern
- Develop patterns for square, rectangular and polygonal prisms cut on slopes, and for mitred copings and gutters at square and non-square corners
- Develop round pipe patterns on the mean diameter, divide them appropriately for their size, and lay out pipes cut at an angle from drawn or calculated ordinates
- Lay out two-piece elbows of any angle from the turn angle and centre line dimensions, and cut both pieces economically
- Apply the elbow rule to multi-piece gore elbows, calculate the sizes of end and middle pieces, and nest a complete elbow on one blank
- Lay out the cheeks, throat and heel of radius and square-throat rectangular elbows and check radius-to-width ratios against the specification
- Find lines of intersection with cutting planes and develop branches and holes for tees, offset tees and laterals
- Calculate the travel, run and roll of round and rolling offsets, lay out rectangular offsets, and develop symmetrical round Y-branches
- Add seam, lock and joint allowances from a shop chart, offset them correctly on curved edges, and lay out notches
- Plan, develop, nest, fabricate, check and record the patterns for a real fitting order from a fitting schedule
Course content
12 lessons · 2 h 45 min total · final exam
- 1 Geometry for layout 16 min · quiz
- 2 Orthographic views for layout 14 min · quiz
- 3 The principle of parallel line development 13 min · quiz
- 4 Square and rectangular prisms 15 min · quiz
- 5 Round pipe and pipe cut at an angle 13 min · quiz
- 6 Two-piece elbows 13 min · quiz
- 7 Multi-piece gore elbows 13 min · quiz
- 8 Rectangular elbows 13 min · quiz
- 9 Tees and intersections 13 min · quiz
- 10 Offsets and breeches 16 min · quiz
- 11 Allowances for seams, locks and metal thickness 13 min · quiz
- 12 Capstone: a gore elbow and a lateral for Ashgrove 13 min · quiz
- E Final exam 20 questions
Requirements
Recommended background. You can start any course at any time.
Description
Laying out patterns by parallel line development, followed through a first-year apprentice at a Halifax sheet metal contractor: layout geometry, orthographic views and true lengths, cut prisms and mitred copings, round pipe cut at an angle, two-piece and multi-piece gore elbows, rectangular elbows, tees and laterals, offsets and breeches, seam allowances and notching, and a capstone gore elbow and lateral for a school retrofit.