Five tips for rapid prototyping and plastic design


1. Observe and understand real-world application.
Getting engineers into the field can help clarify what the customer wants and what the real-world application of the part will be in the field. For example, seeing first-hand the harsh clamping process that injection machine is exposed to enables the design engineer to give more consideration to the device’s components, such as sealants, materials, buttons, etc. It also helps engineers create more rigorous test protocols so the device’s safety and reliability can be accurately verified and validated. Without this knowledge, it’s likely that many important parameters related to the device’s operation and handling will be overlooked in the testing process.

2. Design for Manufacturing/Design for Assembly.
DFM/DFA helps finalize all the features that add cost associated with manufacturing time and material. The goal is to ensure a smooth transition from design to full-scale production and prevent potential manufacturing issues as early as possible. Without careful consideration of the assembly process during the prototyping stage, it’s likely that manufacturing will be more difficult, timely, and expensive than planned. For example, thorough examination of a prototype may reveal that more clamping points need to be added to the design to accommodate a torque requirement during assembly.

3. Collaborate with machinists.
A designer’s best ally is coordinating with a prototype machinist early in the design phase—even before a prototype is made—this helps alleviate issues that may hold up production. Because the machinists have extensive knowledge of the machines on the manufacturing floor and what the machines’ capabilities are, they can offer invaluable feedback about the manufacturability of the design. In addition, the machinist’s familiarity with tooling, production machines, and assembly makes them an essential resource for suggestions on how to modify the design to accommodate manufacturing capabilities while still meeting the customer’s requirements.

4. Use prototyping technology productively.
Prototype machines like 3-D printers and direct metal laser sintering machines reduce time and cost because parts can be made and tested quicker. However, the creation of the prototype isn’t as valuable without feedback from machinists and producing a new prototype after each design change for the customer to review.
The ability to prototype in-house makes it faster, easier, and less costly for part designers and engineers to communicate their design intent to the customer. By being able to see what the design specifications produced and feel the device in their hands, both the customer and designer can more accurately evaluate whether or not the design is on track. And if changes need to be made, modifications can be incorporated and tested for fit, form, and function in hours instead of weeks.

5. Run pre-production.
Preproduction bridges the gap between prototyping and manufacturing, strengthens communication and collaboration between manufacturing and engineering, and accelerates the production process. For example, if there’s a feature that requires a unique drill size to create a distinct hole in the device, a preproduction run might reveal that a slight update to the design will allow a standard drill to be used instead a custom tool or fixture.