I love these of type drawings the most. Conceptual layouts are drawings without engineering format and never released into document control. This drawing is not subject to drawing standards except within the content of the design geometry. Designers can put anything they want on these drawings. The only thing of concern to the designer is how the geometry can be extracted to create other drawings like fabrication drawings, assembly drawings, interconnect diagrams, cable harness assemblies, etc. Remember the layout is going to be used as reference in the design review meeting for everyone to see and brainstorm. The conceptual layout summarizes the fundamental nature of the design.
As the CAD designer you need to create the conceptual layout as if you were the engineering manager explaining to the engineering group what needs to be done and to assign tasks. The drawing should cater to the needs of the mechanical engineer, electrical engineer, software engineer, and engineering technicians involved. This usually takes place after gathering enough information from the first design review meeting.
The Conceptual Layout
The Conceptual Layout drawing communicates graphically the details and the general look and feel of the design without all the detailed engineering and development. The drawing is generated from conversations, sketches, and engineering prototypes. The conceptual layout is the starting point of development, the center of conversation in a design review that prepares engineering for the research tasks at hand. Once everyone is in agreement, the project continues into finer detail development. The designer will continue to develop the layout in CAD consisting of the part geometry and anything else important to the development of the product until there is enough detail to start extracting piece parts into drawings for fabrication.
I like to provide a color 3D view and point out features and benefits that need to be part of the product. This is especially true for products that have assemblies or require electronics. The drawing on the right provides one example of this.
It’s during this conceptual layout planning phase of engineering where key decisions are made to outline a product development plan.
The first layout might be a simple orthographic wireframe drawing with front, top, back, and side drawings for fit form and function while designing parts, selecting components, determining placements, size and weight restrictions. The designer should keep in mind cost estimations, make risk and safety assessments, time management of design process, and engineering coordination of mechanical, electrical, structural, and software requirements while creating the conceptual design layout.
While creating the geometry the designer should add the mass property requirements to each piece part in case engineering requires FEA finite element analysis to determine weights, and strengths. The designer should keep in mind of stress points, and thermal expansion especially between dissimilar metals and vibration for parts for example on an aircraft engine.
The designer should also collect specification data sheets of all off the shelf components with height, width, length dimensions, total weight, clearance requirements, and assembly instructions. The designer should also determine if there are any long lead items and be able to work around them. It would be beneficial to also research possible alternative items in place. It’s a good idea to bookmark online catalogs.
As the conceptual layout progresses to the final stages and before extracting peice parts for fabrication the designer should create a complete solid model assembly equipped with mass properties added to the fabricated peice parts and weights added to the off the shelf item geometry if possible. If not able to add weight then leave it off and pencil it in later but keep note of it.
At this point I like to create a sectioned 3-D model of the assembly to get a good visual. Peice parts and components should have different colors to visually separate them.