How Rapid Prototyping Maximizes Savings in Time and Cost
Kagan Pittman posted on February 16, 2017 | 4498 views
POSTIS provides hardware and software, such as the Rapid DWS system illustrated here, to automate postal logistics. (Image courtesy of POST-IS.)
POST-IS provides hardware and software, such as the Rapid DWS system illustrated here, to automate postal logistics. (Image courtesy of POST-IS.)

Rapid prototyping can help SMEs hit the production floor running, by allowing engineers to use computer aided design (CAD) to generate 2D and 3D models of parts or assemblies.

These models can be analyzed and tested through 3D visualization and simulation, and once cleared the prototypes can be made by 3D printers and CNC machines using the original files for fast production.

The team at POST-IS, LLC conceptualize, develop and integrate solutions for the process automation and logistics automation industries, such as package sorting, and sought to capitalize on this technique. 

The company’s Rapid DWS (Dimension, Weigh and Scan) system captures product data, including address information, to allow users to quickly input their product into the sorting process. Rapid DWS provides OCR-quality images through the application of 4K camera technology.

“Alignment and stability of the camera on the system is extremely critical in order to ensure OCR-quality images,” said Rob Stone, president of POST-IS. “POST-IS designed the casing for the camera, and turned to Xometry to provide a rapid prototype of the bracket that supports and aligns the camera.”

Xometry provides rapid prototyping services and connects customers to a nationwide partner manufacturing network in over 35 states, in addition to their in-house capabilities.

The strength of its partner manufacturers provide a unique advantage explained Greg Paulsen, director of project engineering at Xometry. “The diversity of manufacturers in our partner network allows us to dynamically adapt to what the customer needs.”


Rapid Prototyping Parts with SLS

POST-IS selected SLS (Selective Laser Sintering) for initial prototypes of their camera casing. 


An early POST-IS prototype, which was created with SLS and included helical inserts. (Image courtesy of POST-IS.)
An early POST-IS prototype, which was created with SLS and included helical inserts. (Image courtesy of POST-IS.)


The SLS technique was used to build parts out of a strong, flexible nylon material for L-shaped brackets. 3D-printed prototypes included helical inserts installed during post processing.

“The SLS parts were actually designed for a CNC machine, but they’re not optimized for CNC production,” Paulsen pointed out. “We chose SLS [for prototyping] because, for the drill tap requirement for example, polyjet had the better accuracy they were looking for, but it’s a brittle material and it would probably snap if we drilled into it. We encouraged using SLS to compensate on the tolerances. We made a couple of prototypes and it ended up working well.”

The initial prototypes were built in four business days within a five-day lead time. However, a problem persisted in the manufacturability of the parts as they were initially designed.

“Xometry came back to us immediately with the engineering evaluation that, due to the geometry of the part, machining it as-designed would be much more expensive and time consuming than if the bracket were designed in two pieces,” said Stone.


The original one-piece prototype design was split into two separate components to help reduce machining costs. (Image courtesy of POST-IS.)
The original one-piece prototype design was split into two separate components to help reduce machining costs. (Image courtesy of POST-IS.)


If the L-shaped parts were to be milled from a single block of material, all the material but the “L” would be wasted. Removing the material required additional machining time, a speciality end mill and potentially more operations, all of which added manufacturing costs.

“The L shaped part has a little pocket in the bottom of the L,” Paulsen explained. “What that means for a CNC machinist is that I have to take a tool and reach across the long part of the ‘L’ to hog out that pocket. That ended up adding on, per part, approximately USD$250.”

POST-IS moved forward with the new two-part design, suggested by Xometry’s on-call Engineering, which eliminated material waste and resulted in over 40 percent in cost savings.

POST-IS and Xometry Engineering worked together to optimize the two-piece design and Xometry delivered the units, maintaining the original delivery schedule.


The finished product was red anodized. This POST-IS assembly includes a sophisticated camera that can accurately count and route packages. (Image courtesy of POSTIS.)
The finished product was red anodized. This POST-IS assembly includes a sophisticated camera that can accurately count and route packages. (Image courtesy of POSTIS.)

Working with Xometry

POST-IS initially ordered a relatively small number of parts – less than 100 units – but achieved reduced upfront and inventory costs. Since then, the company has scaled up production.

“We’ve just placed our seventh production order for camera brackets with Xometry,” said Stone.

“Xometry provided the engineering and manufacturing expertise for both the rapid prototyping and production manufacturing processes that we needed to get this part made to precision requirements. The combination of 3D printing and machining was particularly beneficial for a fast transition from design to production. The Xometry parts are proven reliable and their contributions to the process were invaluable to our success.”


Sample image of Xometry's Instant Quoting Platform. (Image courtesy Xometry.)
Sample image of Xometry's Instant Quoting Platform. (Image courtesy Xometry.)

Working together with Xometry, POST-IS was also able to save costs through side-stepping the bidding war process by using Xometry’s instant quoting system, access to their partner network and direct communication with Xometry experts through their website.

“The bid wars are history,” said Paulsen. “I think what we add to this is transparency, because the price we share is a fixed price. We ask, ‘why do you need a traditional bidding process’ and look to bypass it completely.”

For more information about Xometry, visit their website.

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