Why are Fabrication drawings indispensable for Fabricators

Manufacturing sector is on the cusp of two major (still ongoing) transformations – adopting new digitization technology and transforming legacy designs to CAD. Fabricators are jumping on the bandwagon to explore the most efficient CAD drafting solutions as per their tooling capabilities.

From furniture manufacturing to architectural components, and process equipment to sheet metal products, CAD shop drawings are an irreplaceable foundation to achieve quality deliverables. When the appropriate drafting platform, an expert CAD engineers’ team and the industry experts come together, detailed CAD drawings can be developed to ensure profitability and global competitiveness.

Amongst all the essential deliverables in form of CAD drafting, fabrication drawings are indispensable for on shop floor to ensure uninterrupted fabrication stage and quality deliverables.

What are fabrication drawings?

A fabrication drawing is a detailed drawing containing information about the fabrication process and instruction for all the components in an assembly or part. It essentially serves as single go-to place for all the manufacturing operations and decision making for shop floor engineers.

What is the purpose of fabrication drawings?

Fundamentally, fabrication drawings bridge the gap between CAD where everything is ideal and realistic manufacturing shop floor where things that always deviate from ideal situations.

Whether the information that the shop floor operator is looking for is about welding, standards, bolting, cutting, pressing, drilling or anything else, fabrication drawings with sectional views answer it.

A well-detailed fabrication shop drawings with Bill of Materials helps getting faster approvals from project heads, lead engineers, and concerned stakeholders for various projects and can influence the profitability of the project, considerably.

As the raw material changes, the details in fabrication drawings change. For example, fabrication drawings for sheet metal inevitably has nesting reports along with other machine operations, while a woodworking drawing would necessarily have the carving details or surface finish and veneer selection. On the other hand, fabrication drawings for millwork developers or joinery manufacturers are more detailed as they are made to fit the space of the building and small miss-match of dimensions leads to rippling effects across the installation site.

What details do fabrication drawings hold?

Some of the types of fabrication drawings and their relevant requirements are enumerated as below:

  1. Fabrication drawings can be either single part drawings, a part of general arrangement drawings, or full assembly drawings depending upon the need. Typically, these drawings contain information for fabrication of parts, connection details and all the manufacturing operations that the raw material has to undergo to attain the final intended product.
  2. At times, fabrication drawings are supplied by the manufacturing firms to extract part Bill of Materials. At several instances, production drawings used in manufacturing plants falls under this category but they may apply to other industries as well.
  3. General Arrangement drawings, often called GA drawings, are the base from where fabrication drawings are extracted and are as much detailed as fabrication drawings, sometimes even more. This drawing includes all the information about how each individual part will fit together to form the final structure, especially in industrial plants.

Furthermore, as the needs or the end-user change, the details warehoused in the fabrication drawings may vary. Broadly, different types of fabrication drawings include sheet metal parts, woodworking drawings, millwork drawings, casework drawings, furniture fabrication drawings and many more. Ideally, the primary purpose of the drawing is to improve accuracy on shop floor and cohesiveness between various shops.

What inputs do you need to create fabrication drawings?

There are considerably many ways to develop fabrication drawings that design engineers adapt based on the project type and information available. Some of these include: 

  1. Parametric 3D CAD Models

Sometimes, the manufacturing firms or the furniture manufacturer has readily available 3D CAD models created for design intent communication. But these simple 3D solid/surface CAD models neither have the information needed by the shop floor engineer nor the information for Bill of Materials. By extracting the geometrical details and following the DFM principles, fabricating drawings are created to assign accurate GD&Ts.

  1. 2D drawings

Manufacturers also share drawings as inputs which need to be converted to 2D CAD fabrication drawings incorporating necessary details. These drawings maybe in any format and need conversion to parametric CAD fabrication drawings. Broadly, these services include:

  • Conversion from paper to CAD
  • Raster to Vector conversion
  • PDF to CAD conversion
  • TIFF, JPEGs, etc. to .dwg and .dxf files
  • Create BOMs from CAD drawings

The primary reason to convert to CAD is to create editable file formats for drawings and enable future design changes and referencing. Additionally, conversion from one format to another format or one design standard such as ASME or ANSI to BS or ISO is easier. Also creating an NC file directly from CAD fabrication drawings using neutral file formats such as STEP or IGES is a good way forward for fabricators majorly using CNC machines.

Automating custom fabrication drawings creation

With the quick spreading needs of design personalization, today most fabricators offer mass customized products. However, quick spreading needs of design personalization, generating fabrication drawings within stipulated timelines is a mammoth task.

Consequently, engineers have developed CAD customization macros and design automation platforms to directly create drawings from using logical programming. Another breakthrough in CAD drafting/modeling process is introduction of interactive product configurator platforms that ease design customization using logical set of rules.

Both these ways facilitate quicker fabrication drawing generation based on a master model previously created. It allows reusing the design intelligence captured once and customizing it as per the client’s needs as inputs for creating fabrication drawings.

Final words: Partnering for CAD drafting for fabrication

Given the needs and importance of fabrication drawings using 2D CAD drafting, it is obvious that they are indispensable for fabricators and manufacturing firms. However, with the current market needs and agility, the in-house resources of CAD design engineers fall short.

At this juncture, having the right CAD drafting and drawings service provider, familiar with the international design and drafting standards and in-depth knowledge of DFM practice is profitable. This enables the manufacturer to see the product exactly as intended and manufacture with precaution and minimizing reworks. Alongside the fabrication drawings, most CAD drafting service partners also deliver the following services:

  • Assembly and part drawings with BOM
  • Components drawings
  • Manufacturing detail drawings
  • Create 3D model from existing drawings and photographs
  • Casting drawings
  • Sheet metal drafting drawings
  • Woodworking drawings
  • Cabinets drafting
  • As-built and mark-up drawings

CAD drafting solutions for fabrication drawings are just the right prescription for fabricators today. These solutions bridge the gap that exists between designers and shop floor engineers to bring down the lead time and improve profitability.

About the Author:

Usha B. Trivedi is a mechanical design engineer at Hitech Engineering services – a company invested in industrial CAD drafting, modeling, and design automation. Ms. Trivedi writes about solution finding approach in CAD and design automation challenges backed by her years of exploration in industrial designing in furniture, millwork, and metal fabrication designs.

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