DESIGN TIP: 6 Undercut Techniques to Improve Moldability

Undercuts are those complex features in an injection-molded part that prevent its ejection from the mold. They can be found on thousands of everyday parts, from the threads on a fastener to the slot for the power switch on a smart phone case.

The left image (1), illustrates a clip with undercut feature. The right image (2), shows an access hole beneath the undercut that allows the mold to protrude through the part and provide the needed latch shutoff geometry.

In our latest tip, we cover different injection molding design techniques to successfully integrate undercuts, and ultimately, improve overall part moldability.

This month’s tip discusses:

  • Parting lines
  • Side-actions
  • Bumpoffs
  • Hand-loaded inserts
  • Telescoping shutoffs
  • Additional considerations

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On-Demand Injection Molding Helps Med Device Firm Bring Vision to Blind

Helping blind people gain a sense of vision—and doing so through their tongues—sounds like pure science fiction.

Wicab Inc.’s BrainPort V100 is a wearable device for the blind that enables users to process visual images with their tongues.

It’s now a reality, however, thanks to the BrainPort V100, a wearable medical device developed with help from Proto Labs’ injection molding production process. The device enables users to process visual images with their tongues, and users say the effect is like having “streaming images drawn on their tongue with small bubbles,” according to Wicab Inc., the BrainPort’s Wisconsin-based maker.

That comes from the vibrations or tingling that users feel on the surface of their tongue as information about their environment—captured by a small video camera on the BrainPort headset—gets converted into patterns of electronic stimulation through a small, electrode-embedded mouthpiece.

The BrainPort V100, already for sale in Europe and Canada, achieved a breakthrough recently when the U.S. Food and Drug Administration (FDA) approved it as an assistive device for the blind and visually impaired to use in conjunction with other aids such as a white cane or guide dog.

Wicab turned to Proto Labs for on-demand injection molding production components to develop and launch this technology, including the existing BrainPort V100, and a new model now in development, the next generation BrainPort Vision Pro.

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Security Device with GPS Tracking Wins Cool Idea! Award

Product designers at Sleeping Beauty, a German-based company developing an internet of things security device, are the latest recipients of the Proto Labs Cool Idea! Award.

After having his automobile stolen, Jakob Lipps, co-founder of Sleeping Beauty, went searching for a solution to make sure it never happens again. Unable to find a solution, Jakob and his co-founder began developing it on their own. This led to the creation of a compact security device now known as Sleeping Beauty.

Photo courtesy: Sleeping Beauty

Sleeping Beauty uses GSM and GPS technology to track the location of valuable possessions anywhere within cellular network coverage. Thanks to the “Prince Charming” processor (ARM Cortex M0+) inside Sleeping Beauty, the standby time is unprecedented. Sleeping Beauty will sleep undisturbed for up to one year and report its location and remaining battery life at regular intervals via the smartphone app. In Sleep Mode, “Prince Charming” needs only 270 nanoampere. If the device detects movement, it will wake up and send location data to its owner’s smartphone.

“In a market cluttered with complex gadgets, Sleeping Beauty is an elegant solution for a variety of common problems,” said Proto Labs founder Larry Lukis. “Its simple and intuitive design makes it well-suited to succeed in the consumer marketplace. We are excited to support them as they bring the device into production.”

HAVE AN INNOVATIVE PRODUCT DESIGN? APPLY FOR THE COOL IDEA! AWARD TODAY!

3 Ways to Improve Operations with On-Demand Production

On-demand production of parts not only accelerates time to market, but reduces total cost of ownership since it eliminates the large capital expenses of traditional injection molding. Here are three ways on-demand production reduces your design risk, accelerates your product’s time to market, and saves you money along the way.

1. Bridge Tooling
Once you’ve finalized your product design, there’s often a gap between the end of product development and production. Leveraging rapid injection molding with cost effective, aluminum tooling can help you get to revenue more quickly while you wait for your production manufacturer to finalize steel tooling.

2. Supply Chain Emergencies
On-demand manufacturing provides a reliable alternative if global shipping delays or other disruptions in your supply chain arise—minimizing any potential loss of revenue. Further, products with high demand volatility can be more easily managed with on-demand manufacturing.

3. Low-Volume Production Runs
Before committing to large-volume production runs, validate your product design with low-volumes. Pilot runs can aid in testing assembly processes or gauging market demand. And, on-demand production is an economically viable solution for products with relatively low sales volumes—typically in the few thousands or hundreds of units.

Click to enlarge the on-demand manufacturing infographic:

The Short List is a regular compilation of quick tips, trends, and timely topics of interest.

Design Complex Components with Insert Molding

Low-volume injection molding isn’t limited to just simple parts. At Proto Labs, we have the ability to manufacture complicated parts using side-actions, hand-loaded inserts, overmolding, and have now started beta testing our insert molding process.

Instead of a mold that produces a final part using two separate shots like overmolding, insert molding generally consists of a preformed part—often metal—that is loaded into a mold, where it is then overmolded with plastic to create a part with improved functional or mechanical properties.

A threaded insert is placed atop a mold core where plastic is molded over it to form the final component.

Threaded Inserts
One way insert molding is leveraged is with threaded inserts, which reinforce the mechanical properties of plastic parts’ ability to be fastened together, especially over repeated assembly. Self-tapping screws work well with softer plastics, but they can become easily worn and/or cross threaded, and fail to perform well, which results in damaged parts that need to be replaced.

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