By Olivia Cahoon
Part 2 of 2
Three-dimensional (3D) printing allows print providers, manufacturers, and 3D printing service bureaus to create custom objects from a variety of materials. Special finishing techniques bring 3D printed models to a new level with the ability to add texture, color, and embossing.
Rapid Prototyping
Founded in 1995, Custom Prototypes Inc. started with two employees in Toronto, Canada. The company originally produced handmade prototypes distributed locally.
“The idea behind this was to open a world of possibilities in design, fabrication, manufacturing, and repairs, and to offer 3D printing services at industry-grade quality standards,” comments Andrew Sliwa, director, Custom Prototypes Inc.
Today, it operates with seven employees in a 5,000 square foot workspace. Custom Prototypes offers 3D printing, CNC routing, vertical milling, sand blasting, translucent dying, and priming and painting services worldwide.
The company uses a variety of 3D printers from Zrapid for stereolithography (SLA) printing to Renishaw direct metal laser sintering (DMLS) machines for metal 3D printing.
SLA is a laser-based technology in the vat photopolymerization family. Parts are created by curing polymer resin layers using a UV laser beam. “This technology produces highly accurate and smooth surface finish parts,” comments Sliwa.
SLA is Custom Prototypes’ most popular 3D printing technology. It offers a maximum build size of 600x600x400 mm and is often used for applications like detailed models, form-fitted prototypes, and general purpose parts.
DMLS is a laser-based 3D printing technology that uses powdered metals. The high-powered laser beam melts and sinters the metal powder by each layer, continuing until the object is fully formed. Clients seeking functional prototypes, high-temperature resistance parts, and applications with intricate detailed components often use this technology. It offers a maximum build size of 250x250x250 mm.
With its 3D printing technology, Custom Prototypes produces a variety of 3D printed objects from architectural models to consumer products, medical devices, and space, aviation, and automotive parts. “All clients have different ideas and we create what they need,” says Silwa.
Currently, 90 percent of the 3D printing service bureau’s work is 3D printing. For SLA printing, it uses DSM Somos resins. For metal 3D printing, the company offers 316 stainless steel and maraging steel.
“With 3D printing we can allow ideas to develop faster than ever—a dream, concept, or an invention can go from a simple thought to a produced part that one can hold,” says Sliwa. “The ability to develop a tangible object from design in a matter of a few hours or days as compared to months with traditional methods helps our clients stay ahead of their competitors.”
The shop also benefits from 3D print technology’s fast turnaround times. According to Sliwa, the technology is not only efficient but also cost effective compared to traditional machining. It allows designers to create production-ready prototypes before investing in expensive molding tools. “3D printing is an ever-growing technology that has expanded from plastic to multiple materials to choose from and has given us the ability to form complex geometry objects that were historically impossible to build.”
Impressing the Experts
In early 2018, Custom Prototypes decided to experiment with its 3D metal printing technology. The company embarked on a journey to produce a more complex and organic build unlike any project it ever created.
After researching modern and experimental 3D prints, the company decided to produce a first century Roman helmet. The helmet’s entire skeleton was 3D printed in seven different parts using DMLS technology and 316 stainless steel. It then underwent a lengthy finishing process consisting of manual and electronic polishing.
After the metal parts passed surface quality control, it underwent a plating procedure consisting of copper, nickel, chrome, and 24-carat gold.
The helmet’s features—including gems and stones—were 3D printed with plastic SLA materials Somos Watershed XC11122 and Somos Evolve. Each piece was dyed, painted, and finished to resemble a realistic historical representation of artifacts found in first century BC.
The helmet’s inner liner was printed with Somos Evolve SLA material and finished using dye and paint. It also included a subtractive color removal technique to mimic the finish of real crocodile leather.
To create authentic red Mohawk hair for the Roman helmet, Custom Prototypes used a special in-house printing secret that allows for vertical substructures to print without the use of additional support. After printing the tiny fibers, the company hand dyed and plasticized it with a molecular lubricant and finished with a clear coat.
After printing and finishing, the helmet’s parts were assembled together with most of the parts designed to press-fit into the helmet’s shell and the remaining components attached with a special metal adhesive.
The 3D printed Roman helmet is now a staple of Custom Prototypes’ 3D printing capabilities. The project claimed first place at AMUG’s Additive Manufacturing technology competition for advanced finishing. It is currently available for sale on Ebay at $30,000.
A No Stress Process
Utilizing a variety of design, finishing, and manufacturing technologies, Custom Prototypes offers expert advice on how clients should create custom 3D printed models. The 3D printing service bureau continues to push the limits when it comes to 3D innovation and design.
Click here to read part one of this exclusive online series, AEC 3D Printing.
Jun2019, DPS Magazine
