How to choose a rapid prototyping process

Product designers are generally well acquainted with the various rapid prototyping processes available today, but there are occasions when machine builders also need to use rapid prototyping or rapid manufacturing processes. Machine designers, however, are less likely to be familiar with the advantages and limitations of the various processes. Fortunately Proto Labs, the group to which First Cut Prototype belongs, has published a White Paper that will bring some clarity to a field in which technology has evolved dramatically in the last ten years.

Entitled Prototyping Process - Choosing the best process for your project, the White Paper has three main sections as outlined below.

Quick Reference Prototyping Process Comparison

This section starts with a general introduction and then presents a very useful table that lists the main rapid prototyping processes (but not all of them - laminated object modelling (LOM), for example, is not included). For each process, the table provides a few words to describe the process, indicates the range of materials with which the process can be used and the material strengths, and gives an indication of the surface finish that can be achieved.

Process Comparisons for Prototyping Options

Following on from the table, the White Paper then provides a more detailed description of the processes and lists the pros and cons (advantages and disadvantages) of each. There is also a photograph of a small component produced by each process.

Choosing a Process

Importantly the White Paper recognises that different projects have different requirements, hence the optimum rapid prototyping process will not always be the same. A two-step process is provided to help designers select the best process for each application. The first step uses a decision tree that enables the user to identify the most important factors and the attributes that are likely to be of interest (such as quantity, material choice, colour, tolerance and complexity). In the second step a table shows how each rapid prototyping process fares for the required attribute, with a simple rating system of good, fair and poor. By the end of this process, the designer should have a good idea as to which prototyping process (or processes) might be best for producing the required component.

Also included in the White Paper is a glossary of some of the terms used, plus there is a summary that touches on subjects such as manufacturability and design viability.

The White Paper is a useful introduction to various rapid prototyping techniques, though it is not comprehensive and it is restricted to rapid prototyping rather than also covering rapid manufacturing. Nevertheless, as a free PDF (2.5MB) it is definitely worth downloading if you are new to rapid prototyping and need some advice on choosing the right process. Download the White Paper now from the First Cut prototype website.