A Guide to General Assembly Drawings

If you’re an inventor, designer, engineer or manufacturer, it’s likely that you’ll need general assembly drawings. But what exactly are general assembly drawings in CAD (computer-aided design)?

What is a General Assembly Drawing?

A general assembly drawing of a product or a structure includes a list of the parts or components, the general arrangement of the components, how the parts fit together, and the dimensions of the components.

General assembly drawings are necessary for any product, design or invention that has more than one part:  From computers to aircraft, lawnmowers to heavy machinery, skateboards to baby carriages – they all need assembly drawings.

Some assembly drawings are simple (think about the last piece of IKEA furniture you purchased and assembled). Some CAD assembly drawings are complex (like the motor for your automobile.) General assembly drawings all have these things in common:

• They list all the parts
• They list all the sub-assemblies
• They include a Bill of Materials that lists each part number, part name, and part quantity.

Some of these drawings provide instructions on how to assemble the product at a manufacturing level, while others may list part numbers for consumers to re-order parts. Instructions may include information such as how to fasten parts together, or what types of lubricant to use.

The Importance of Accuracy With General Assembly Drawings

How many times have you purchased something online that you had to assemble? And how many times were those general assembly drawings show a bolt that wasn’t included, or described a fitting that didn’t “fit?” We’ve all had that happen. While it’s annoying, it’s not usually a matter of safety, nor does it cost huge sums of cash when the item doesn’t go work as it should.

But, general assembly drawings that represent a machine or component to be manufactured and used in industry, transportation, heavy construction, aerospace or other similar applications must be accurate!  Lives can be at stake. Millions of dollars can be on the line. The assembly drawing must represent the form, fit and function of a product. It must verify how that product is put together. And, often, it must be simulated in a virtual model and tested via FEA in order to determine that the end product will work as it should.

3D Models and General Assembly Drawings

When you develop assembly drawings from 3D models, you link together a group of solid parts, bringing them together into a collection of joining components to create a single product. This virtual arrangement allows the designer to examine interfaces between parts and to look for interferences. By adding material, color, and lighting, the designer can also view the actual appearance.

An engineer or designer has the control of the 3D assembly and can see in vivid detail what two-dimensional drawings cannot show. Different type of mechanical assembly drawings includes outline drawing, erection drawings, assembly work drawings, assembly diagram, part assembly drawings, and general assembly drawings.

Contact CAD/CAM for General Assembly Drawings

CAD / CAM Services provides 3D drawings for assembly, casting, machining, and sheet-metal drawings to manufacturers, engineers, fabricators, and consultants. By ensuring that all 3D models and drawings that we produce meet industry standards and contain appropriate formats & layouts as required by our customers.