Signicast blog 
Prototyping for Mass Production
An effective prototype should be more than a replica of your component. It should be able to withstand strength testing, hold the geometry of your final part, and validate proof of concept. A good, functional prototype is the foundational stepping stone towards transitioning your project off the drawing board and into mass production.
Signicast offers various prototyping technologies to suit your individual project, and we’re staffed with a team of engineering experts with experience producing prototypes for a variety of industries and applications.
Prototyping options for productive testing
To choose the most effective prototyping process, you need to determine your end component’s physical properties and testing requirements. These requirements will narrow down your available prototyping options. Once you’ve done that, you can pursue a functional prototype utilizing one of these avenues:
Short-run, hard tooled prototype
If you’re looking for a prototyping process to produce a large number of parts with the exact mechanical and physical properties, dimensions, and tolerances of your end component, a short run hard tooled prototype is the most effective option. The hard tooled prototype entails an up-front tooling cost, but produces prototypes at a lower piece price than processes that utilize SLAs or PMMAs. If your project requires an exact prototype and rigorous yield strength testing, a hard tool prototype is the way to go.
3D ceramic printing
Through additive manufacturing, "ready to pour" ceramic shells are formed without any tooling or patterns – thus speeding up the time to production. DDM’s LAMP™ (Large Area Maskless Photopolymerization) ceramic 3D printing technology brings more advanced capabilities—including topology optimization and generative design—for achieving the most complex components with unprecedented speed and precision.
Considered a hybrid investment casting method, 3D printed shells transition perfectly to traditional foundries and create high-quality products that meet the specifications of traditional investment castings. The ceramic printing technology, including the equipment, hardware, software, and materials, is fully consistent with the quality and precision of investment casting operations. And in terms of dimensional accuracy and surface finish—the 3D castings are directly in line with injection molded wax patterns.
3D printed wax pattern
If you’re looking for design validation, proof of concept, fill validation, or for your prototype to mimic the mechanical properties of a true investment cast component, 3D printed wax patterns are efficient with a fast turnaround time. Our printed wax patterns are created in-house within hours and immediately processed into fully functioning metal components. Recent technological advancements have made it much easier to validate surface finishes on these prototypes. The biggest limitation for this process is component size—printers will only accommodate parts about the size of a Rubik’s cube or smaller.
A 3D printed wax pattern and the cast prototype
SLA (Stereolithography)
SLA is similar to our 3D printed patterns, but chosen when part size is larger than our 3D printer capacity—about the size of a sheet of paper, 6 to 8 inches high. Much like 3D printed wax patterns, SLA prototypes mimic the mechanical properties of a true investment cast component and are an effective method of prototyping for fit and design validation. Aside from size, the main difference between 3D printed patterns and SLA patterns is the pattern removal is far more manual.
PMMA (Polymethyl methacrylate)
PMMA patterns are similar to SLA patterns and accommodate parts that exceed the size capabilities for SLA. Similar to 3D wax patterns and SLA, PMMA is good for dialing in surface finishes, fit and design validation, and mimicking the mechanical properties of an investment cast component. PMMA is also a great indicator of the strength and repeatability of complex geometry.
Machined from solid
Machining from solid bar stock is typically an extremely fast process and great for producing a dimensionally-accurate part to measure fit and proof of concept. To guarantee speed, this process is best suited to cut low volume, aluminum alloy parts. Parts cut from stainless steels and carbon steels are cut more slowly, and the longer run time has the potential to increase cost.
DMLS (Direct Metal Laser Sintering)
This process suits prototypes with complex geometries and exacting, untoolable features. With this process, however, you’ll want to consider that DMLS can’t usually hold the same mechanical properties as a true investment casting. So while this process is great for proof of concept and demonstration, it won’t hold up to real-world testing.
Which prototyping process is the most effective for mass production?
Over the course of a successful product launch, you could conceivably use a combination of several different processes. The most effective prototyping process for the current stage of testing depends on the scope of your project and how close you are to product launch.
Eventually, when you’re close to running your project at mass production capacity, we recommend moving into a short-term hard tooled investment casting run. This way, you’ll be able to effectively test and validate each requirement of your end component.
Get the most out of you prototypes
One of the most important—and often undervalued—part of the prototyping process is getting your supplier involved in the design process as early as possible. Ideally, you want to design your prototype for optimal manufacturability, and the most straightforward way to do this is to involve design engineers who are familiar with the investment casting process. In doing this, you can avoid setbacks in the prototyping process, like having to re-design a part to certify mold flow and solidification, re-design for castibility, or re-design for alloy requirements.
Signicast has the know-how and experience to optimize the production process from the beginning so that you can get the most out of your prototype and streamline the transition to mass production.
Interested in learning more about prototyping effectively for mass production? Download our free webinar Prototyping for Production! Click below.
