Designing Plastic Parts? Why You Should Listen to Your CAD Service
Nearly everything these days is made from plastic or made with plastic parts. In fact, in developed countries, nearly a two-thirds of the plastic that's manufactured is used in buildings or for manufacturing. For instance, today's buildings include plastic piping, plastic plumbing parts and vinyl siding. Today's automobiles are made of up to 20% plastic. Furniture and toys also make good use of plastic. Plastics have many uses in the medical field as well.
In the United States, the plastics industry is the third-largest manufacturing industry, and growing, with its use in injection molding and 3D printing in high demand around the world. With plastics being a key building block in manufacturing, and, since many of our clients come from the manufacturing sectors, we get our fair share of CAD work related to plastic parts design and development.
In this post we're going to tell you about one of those projects. Because we respect our clients' privacy and honor all non-disclosure agreements to which we are a party, we will not identify the specific client. But, we think there's a point to be made -- perhaps not a morality tale, as such -- but at least a cautionary tale showing that sometimes a knowledgeable CAD outsource service can save a designer from a costly mistake.
Design to STEP File
Files with the .step extension are usually 3D model files created in the STEP file format. STEP stands for Standard for the Exchange of Product Data. This ISO standard exchange format is used to distribute 3D data files (such as CAD files) in a format that can be viewed by a variety of software applications. The .step file extension is interchangeable with the .stp file extension.
In the example we're citing, a client sent us two AutoCAD drawings -- one that needed to be converted for plastic printing using a 3D printer; and one that needed to be converted for injection molding.
We always use best practices to predict and avoid injection molding or 3D printing defects and to optimize our clients' designs. This quality control step, and the insight it brings enables us to advise our clients about the manufacturability or printability of their designs.
Conversion and Review
The drawings in question included a lens mount and housing, along with an over-mold for use in a marine component.
We noted that the mounting holes on the housing were not symmetrical with the over-mold. The variation was slight, less than .02" but, in an application with little or no tolerance for error, it was too much. We alerted the client to the discrepancy. Because the design for the housing and the lens needed to be universal for both the left and right sides, it would have created not one, but two problems when the first orientation of the design was manufactured, then reversed horizontally to manufacture the second side.
Reliability and Accountability
While manufacturing companies use CAD services for many reasons: (1) to alleviate heavy workload; (2) to avoid cost over-runs; and (3) to speed production, there is an additional benefit that is often overlooked. That benefit is the reliability and accountability that a third-party review can bring to your designs.
There are many CAD outsource services, and, as with any service, some are better than others. Even when you need just a "simple" conversion, it pays to use a company with the integrity, the reliability and accountability to treat your work like it's their own. Sometimes that means pointing out errors and helping you to correct them.