A Guide to Selecting the Right Rapid Prototyping Method

Choosing Between Different Rapid Prototyping Techniques

Since the late 1980s, rapid prototyping has become a preferred manufacturing process. It allows for quick production and assembly of parts, prototypes, and final products. There are many rapid prototyping techniques that have been developed, enabling companies to demonstrate ideas, test new products, and refine their designs.

The most common techniques used include:

• Additive Manufacturing: Known as 3D printing, additive manufacturing involves fusing material together, one layer at a time, in three dimensions. A 3D printer is used during this process. For plastic, Selective Laser Sintering (binding together powdered material) or Fused Deposition Modeling (fusing filaments of thermoplastic material) may be used, while metal 3D printing is accomplished with Direct Metal Laser Sintering.
• Subtractive Manufacturing: Pieces of material are removed from a solid block until the desired shape is achieved. This is an alternative to adding material layer by layer Subtractive manufacturing can involve turning or using a moving cutting tool to cut a rotating part; or milling, in which high-speed rotation is applied to the tool itself. For drilling, a cutter drills holes while rotating on the part.
• Casting: The initial part, used later as a reference model, is created using additive manufacturing. Next, a rubber mold is formed around the 3D printed part, cured, and then removed. The mold is then filled with a resin or other molding material to form identical parts. Casting is effective for high quantities of prototypes that are somewhat complex. It is a multi-step process and requires more time than other methods.

Other techniques for developing rapid prototypes include laminated object manufacturing, which involves gluing together and cutting layers of adhesive-coated paper, plastic, or metal. Drilling or machining may be performed after the printing process. This technique is suited for relatively larger parts and when readily available raw materials are required.

Solid ground curing uses a photopolymer and UV lamp for 3D printing. It can create prototypes, models, patterns, and production parts. One advantage is it does not require a support structure (wax fills voids in the design). With selective laser melting (also known as direct metal laser sintering), a high-power laser melts and fuses metallic powders into three-dimensional parts.

Selecting the Best Rapid Prototyping Technique

With rapid prototyping, the differences between techniques make each one best suited for different applications. The primary factors to consider are:

• Expected product quality (a rough design or functioning prototype)
• Product fidelity (desired look and feel of the manufactured item)
• Part complexity (for greater complexity, more precise rapid prototyping tools should be used)
• Material properties (how durable or flexible the final product will be)
• Quantity (some rapid prototyping machines are better suited for high batch volumes, while others are effective for small numbers of parts).
• Resources (Time, budget, material availability, and other resources can help you choose the best technique)

If you’re unsure of the best rapid prototyping technique to use, contact Laszeray Technology, LLC today at 440-582-8430. Using 3D printing, we can produce full-scale prototypes within hours. Contact us to discuss your production requirements and the machine tools and rapid prototyping software used to bring designs to reality.