Patternmaking 101

Following is an outline of the future content of an illustrated instructional electronic book to be at this site for those interested in learning the art of Pattern making is the core of most production manufacturing. These concepts are the beginning of most mass produced products made of metal, plastics and many other medias.

As we write this tome the lines of this outline will become links to the pages with further content. The outline in and of itself is informative. We at JAG Engineering hope you enjoy our efforts. We invite your comments, criticisms, arguments and/or corrections to the material.

E-Mail:
gaylen@jagmold.com

Pattern making overview and divisions of complexity
- Simple prismatic (stacked blocks) to the complex prismatic (P51 Mustang)
- Sculptured, sweeping contours. NURBS & Bezier based. (Mr. Bezier works for Matra Datavision)
- Outsized, oversized, practical and impractical. The build plan is more complex than the design.
- Mixed complexity and the assignment of work to those most qualified.
The concept of Draft and why it is ignored by product designers.
- Dimensions plus draft, instances in packaging
- Dimensions minus draft, instances in packaging
- Backdraft!
- The sun must shine on it all and ways around this hard/fast rule
  - Flexible pattern materials
  - Shrinkage in production process to release
  - Skew or rolling part removal schemes
- Minimum draft specifications, the pattern maker's choice?
Parting lines
- Simple flat-vertical or horizontal, the process decides.
- Complex geometric/prismatic (conventionally machinable) or "offset"
- Complex sculptured (EDM or CNC only) using normals around high points of model
Shrinkage or Pattern expansion principles
- Stacked factors in master patterns for multiple precesses
  - A factor is just that-it relates to the number of units used
  - Isotropic or consistent scaling in all axes,XYZ
  - Anisotropic scaling explained and instances it is used
    - Shoe or clothing layouts
    - Process adjustments
  - Consistent use of shrink scales
  - Expansion of CAD files for pattern purposes
  - Use of 1 unit telltale in CAD file to log expansion actuals
Yaw-Pitch-Roll, or Turn, Tumble, Flip
- Communicating standards in pattern shop
- Six axes of freedom
Coordinate systems
- Cartesian system of XYZ
- Polar system standards
  - 2D navigation
  - 3D polar navigation
- Mixing of coordinate systems for convenience and speed
Basic layout concepts
- Using vertical height gauge 1 axis at a time
- Using layout machine 3 axii at a time
- Using square and parallel panel scribing gauge
- Use of mouse gauge, a 3D projection tool
- Use of the layout knife and rule, accuracies to be expected
- Use of digital calipers at 1:1
- Use of CAD as a proving tool and for layout simplification
  - Put in what you know and ask CAD for what you don't
  - Proves quality of information supplied
  - Will surface disparate misinformation
  - Laser printing layouts for templates
  - Postit note adhesive
  - Plotter tricks, vinyl cutter knives
- Necessity of maintaining sharp tool quality for layouts
  - Irrigation ditches or layout lines?
  - Reflects personal work ethic but takes expensive time
    - Use of expendable tools
    - Tools are cheap
Concept of Book Match
Core Prints
Closeover
Sand Groove
Shutoffs - adjustments on coreprints
Basic horizontal parting line gating system