Sheet metal designs vary from simple to complex and need thorough thinking to get from concept to manufacturing. Old ways of using paper and pencil for even a simple design take lot of time and several iterations to deliver the actual shop floor fabrication needs. On top of it, only a skilled designer and drafter would be able to visualize it completely; leaving other manufacturing stakeholders in dilemma.
Modern technology of CAD drafting and 3D drawings not only simplifies and fast tracks sheet metal design but also improves productivity by cutting time and removing ambiguity among stakeholders. A clear 360-degree visualization of sheet metal designs using 3D CAD drawings and annotations makes manufacturing efficient.
Challenges to sheet metal manufacturers
Typical stages of sheet metal fabrication from design to shop floor include conceptualizing, sketching, material selection, and selection of right manufacturing technology. Operations like forming, cutting, bending, punching, drilling, etc. are performed in a factory to create parts, subassemblies, and assemblies. During these processes, manufacturers face challenges such as:
- Visualization: Lack of creative thinking and visual capabilities during design drafting and manufacturing.
- Iterative process: Creating concepts that capture the customer requirements using pencil on paper (making sketches) consumes a lot of time, and many times do not represent true pictures.
- Complex and detailed engineering: Detailed engineering drawings demand having specific skills and applied knowledge of engineering and manufacturing rules (DFM, DFMA, GD&T, etc.)
- Interpretation of design intent: Interpretation of design intent from 2D drawings remains a major concern among all the stakeholders who are from a non-technical background.
How CAD drafting and 3D drawings improve the sheet metal design productivity
Shop floor drawings are the backbone for any sheet metal part manufacturing that communicates the need of material, manufacturing process, and final form & fit. Without part visualization and a complete understanding of detailed drawings, no manufacturer can produce the right sheet metal product.
Knowing this complexity, the 3D CAD technology has incorporated sheet metal-specific programs that improve the productivity of designers, drafters, and overall functions of manufacturing.
Modern 3D CAD tools like SolidWorks, Inventor, Creo, SolidEdge, etc. with specialized programs on sheet metal design and detailing accelerate the process from concept to manufacturing. These CAD tools offer several benefits to the design engineer, CAD drafter, and the manufacturer and improve their overall productivity.
Following are some major impacts of CAD drafting and 3D CAD tools to deliver quick concepts:
Quickly generate 3D concepts: 3D CAD tools offer easy to use toolset of curve, line, points of 2D and 3D, surfaces, solids, flange, and facets to rapidly create shape, editing, and evaluation. They enable creating freeform and parametric designs with increased flexibility. Engineers can generate concepts by adopting sheet metal criterion right from beginning or can add it later and convert the raw 3D model into sheet metal model. In essence, they shorten the concept to approval lead time which is a big win for manufacturer.
Automated 3D CAD drafting: Since a 3D model is created line by line and point by point by considering the curve and thickness, the drawings can be generated automatically. It not only speeds up the time taken to create drawings but also ensures to follow the dynamic dimensions as per ISO and ASME guidelines. The designer can automate bends, holes, slots, and more sheet metal features with accuracy and perfect the part manufacturing.
Exploded views for assembly: Exploded views are required when an assembly model has more than two parts so that the right orientation is conveyed. Through the auto-explode feature, the designer and the drafter can directly generate exploded views. While for the final assembly, the user has to apply right ballooning to get BOM requirements and manufacturing (welding and assembly) notes in exploded 3D views.
It enables seamless manufacturing by providing information on the number of parts needed, tools used in the process, precise methods of fabrication and assembly, etc. These views are also handy to simulate animation as they remove manufacturing conflicts and shorten the manufacturing lead time.
Annotations on drawings: 2D CAD drawings can be annotated in CAD platforms to convey the requirements on manufacturing and assembly. An annotation clears many doubts from the shop floor and makes the design right the first time.
Enhanced user experience: 3D drawing views with rendering offer a life-like feel of the physical component. Rotating, zooming, and panning features allow the user to walk through the part to understand detailed design intent. This resolves many misunderstandings among stakeholders and accelerates the process of design approval, order processing, and manufacturing.
Advance 3D drafting: New technology trend of Model-Based Definition (MBD) steps further to accommodate all the requirements in a 3D model itself for design communication between stakeholders. It offers detailed insights for everyone right from the shop floor to design and customers – across the value chain of manufacturing. MBD allows incorporating all metadata requirements into a 3D CAD model making it a single source of truth for customers, sales teams, marketing teams, design and validation teams, production people, and maintenance teams.
Conclusion
Productivity remains the new normal in manufacturing. Sheet metal part manufacturers, designers, and drafters are always in a need of better tools and techniques to represent the true picture of their parts and remain efficient. In a journey to make concepts to detailed shop drawings, productivity gets lost in a conventional way of working.
On the other hand, the use of CAD drafting and 3D drawings for sheet metal enables manufacturers and design engineers to stay efficient by:
- Reducing overall sheet metal product design time in hours
- Adding clarity through 3D visualization of design needs
- Removing all ambiguity across stakeholders
Authored by:
Usha B. Trivedi is an engineer and she contributes in-depth articles for mechanical and industrial equipment designs, furniture designs, and the fabrication sector. Her contributions are primarily focused on enabling engineering professionals, furniture manufacturers, and fabricators to optimize design outcomes through CAD and CAE tools.
