3D printing is a technology used mainly for prototyping and in some cases, depending on the final use of the printed part, as a manufacturing method (rapid manufacturing).
Like in any design process, your design intent must be driven by the possibilities and limitations of the final manufacturing process of your model. 3D printing is not an exception; it offers a huge amount of new possibilities but also carries some limitations. Keep these suggestions in mind, as they will help you to design a successful prototype:
- Define clearly if you are going to print a prototype or a real part. It will be the starting point to determine what technology to choose to build your part.
- Establish priorities: what is the main objective of your part? General design concept, form / fit testing, marketing testing, mechanical resistance testing? Every rapid prototyping technology excels in one of these goals, but may fail in other.
- What external conditions (temperature, contact, abrasion, impact, chemical attack) is the part supposed to withstand? Read carefully the material specifications data sheet before printing your part or submitting it to a service bureau.
- How long is the part required to survive in a specific condition? You may not need an everlasting part. If it accomplishes its objective, it may be economically efficient to choose an entry level technology / material rather than an expensive performance grade one.
Answering the previous questions will help you to determine the technology that best fit your needs.
By using additive manufacturing techniques to build parts you will be able to produce unique prototypes, with features impossible to make by conventional methods:
- Intricate internal channels.
- Internal moving parts with no assembly required.
- Single parts made out of several materials (multi-material parts).
- Multi-color models directly from the 3D printer.
If you prototyped a model intended to be manufactured by conventional method in the future, be careful. Make sure that the final manufacturing technique of the real part can produce the features that you prototyped. Prototyping an awesome part doesn’t mean that you can actually create the same part using conventional methods.
You must also be aware that some limitations may arise, and you should know them to avoid surprises down the road:
- Support material removal: in some cases hollow parts will enclose support material, with no possible way of removing it after the part is built.
- Some materials are not suitable for outdoor conditions like UV radiation, heat or humidity.
- Resistance to impact: most rapid prototyping materials are not intended for rough manipulation or high impact, as they will likely break.
- Some technologies do not provide enough surface smoothness for moving mechanisms or interacting parts.
- If surface finish is important to you, keep in mind that not all rapid prototyping technologies can provide smooth surfaces.
These recommendations will help you to plan ahead and drive your design intent according to your final objective: a successful prototype.