THE ENGINEERIST: Mitigating Production Risk with Prototypes

Editor’s Note: The Engineerist is a three-part blog series written by Michael Corr, founder of Los Angeles-based manufacturing consulting firm, DuroLabs. This is part one.

Startup companies have limited time and money, and, rightfully so, treat them as precious resources. There is constant pressure to get products out to the market fast, and when cash is limited, there is little margin for mistakes.

As an engineering manager, my responsibility is to ensure that the development processes being used by my team to bring parts to production are reliable, repeatable, and properly mitigate risk. For high-volume production, injection molding is the best option for plastic parts but it can be expensive and time consuming—two factors that can severely impact the success of a product launch if there are mistakes.

Waiting 12 to 16 weeks for first articles off a steel mold can be an eternity for a company pressured to get products into production in a shortened nine-month time frame. Any delays only compound the issue, adding pressure on myself, my team, and the company as a whole.

CAD model

Analysts at Proto Labs prepare CAD models for manufacturing.

Automated Quoting
When I was first introduced to Proto Labs almost 10 years ago, I was impressed with its commitment to leveraging modern technology. Its quoting process was simple and quick due to automated online tools. This allowed me to independently configure part options without having to go back and forth with a sales rep to update quotes and lead times. The automation saves hours, if not days, in evaluating various options. Additionally, the design for manufacturability feedback tools, which automatically highlight problems and areas of concern in the parts, save days to weeks of time and potentially hundreds to thousands of dollars by alleviating the risk of re-spinning due to an erroneous part. Again, with time being a limited commodity and a close watch on development dollars, these attentions to detail were very important to me.

The Case for Milled Prototypes
Prototyping before production is necessary to mitigate this risk but it can potentially cost money and take time to produce parts, so it’s important to choose your prototype runs wisely. One risk-mitigating technique I’ve incorporated into my mechanical engineering team’s process is to always produce a CNC-milled prototype of any part that is identified to be injection molded for production. This seems like trite advice, but I was amazed at how often engineering teams overlook the value of this step. Even 3D printing, another valuable prototyping tool, is often not as effective as a milled part if a move to molding is imminent. The advantage of the milled part is a closer approximation to the final molded material properties—not only in strength but also look, feel, and toughness when handled.

CNC machining

Proto Labs has hundreds of CNC machines, which enable quick-turn milling of functional prototypes and production parts.

I have now built several dozen parts with Proto Labs, so I can attest to the quality and expediency of the parts. In just a few days and not much investment, one can have several milled parts in-hand and ready for evaluation. Proto Labs’ extensive library of material options has also allowed me to select the same exact plastic to be used in the eventual injection-molded parts. This flexibility paired with comparable tolerances and resolution to final injection-molded parts, allows me to reliably use milled prototypes for a full form and fit check. In many cases, I can even use the parts for structural and environmental performance tests, so we can evaluate and make any final tweaks before cutting steel without having to cross our fingers that nothing goes wrong.

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3D Printing Experts Discuss Technology’s Future

3D printing is the topic of conversation in our latest Journal issue, which focuses on the technology’s next dimension—how additive manufacturing is poised to make a giant leap forward in capabilities.3D printing

The cover story includes interviews with three leaders from the 3D printing industry who offer insight on a variety of topics, such as advancements in new machines and materials, a growing demand for 3D printing for production parts, and notable trends in software.

Another feature, “A Cloud-Based Future for CAD,” explores how 3D CAD design software is increasingly moving to cloud-based models, a trend with benefits for both product developers and manufacturers.

Elsewhere in the Journal, our Eye on Innovation column features a driverless bus, a 3D GoPro, and a DIY Bluetooth.

Read the entire Journal here.

We’re always on the hunt for though-provoking content, so send your cool project or article idea to our editor at angelo.gentile@protolabs.com.

Thanks and enjoy the issue!

DFM Analysis, Injection Molding Help Spring Company Reduce Costs

An Illinois-based steel-spring manufacturer recently called on Proto Labs to help reduce component count and save time and money on a device the company uses to market its services to the aerospace, automotive, oil and gas, and medical industries.

Smalley has long equipped its sales force with a small demo device, a handheld “comparator” that shows the relative size and performance of a wave spring—which Smalley manufactures—compared with a coil spring.

The company turned to Proto Labs for help with solving a cost issue when Smalley considered redesigning the comparator to “use them as ‘giveaways’ to prospective customers,” explained Lane Persky, Smalley marketing manager. “We were looking to go from about 20 of the original comparators, which each cost about $100 to produce, to an initial run of 1,000 redesigned comparators at a target cost of about $15 each.”

Proto Labs’ design for manufacturability (DFM) analysis, and its injection molding service, helped Smalley designers create a new comparator, which would require just seven parts. The original comparators each consisted of 23 parts.

“We chose Proto Labs for the company’s reputation and ability to do both advanced 3D printing for prototyping and affordable, rapid injection molding” for low-volume production, said Persky.

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Stereolithography: Sorting Out Surface Finishes

There are a number of factors—resolution, tolerance, material selection, surface finish—to consider when designing for the industrial 3D printing process of stereolithography (SL). For our latest tip, we’ll discuss the four stereolithography finishing options available at Proto Labs, and when it makes sense to use each.

Unfinished

Stereolithography (SL) technology uses a build platform that requires support structures for all features so they don’t float away or collapse during the build process. These support structures are removed after the build is complete, but they do leave visible markings on the part.

stereolithography proto labs

3D-printed parts are moved from the SL chamber after a build finishes. Supports are then removed, parts are UV cured, and a selected finish is applied.

In an unfinished state, after the support structures are removed, dots or nibs are noticeable where structures were attached to the part surfaces. So, when would leaving a part unfinished make the most sense?

  • When a clear part is desired with no custom finishing
  • If you have your own finishing capabilities, or have another shop that can perform post-build finishing
  • To achieve the best accuracy possible

Natural

A natural finish provides a surface finish that absent of dots or nibs, which leaves a more desirable cosmetic appearance. The surface is not as clear on the down-facing surfaces that had supporting structures, but the top surface would remain clear. When should you use a natural finish?

  • On small or delicate features that may be destroyed by additional finishing such as grit blasting
  • On clear parts where down-facing surfaces are not a cosmetic concern

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IMTS Showcases Manufacturing’s Diverse Landscape

Amar Hanspal, attending his first ever International Manufacturing Technology Show (IMTS) at Chicago’s McCormick Place this week, tweeted that the event “is a digital manufacturing Disneyland.”

And really, it’s hard to argue with that assessment, based on the sheer numbers of attendees (more than 100,000 over the week-long event), exhibitors (over 2,000 companies), seminars, and innovative ideas being featured.

Tony Holtz, left, technical specialist for Proto Labs, discusses rapid overmolding at the International Manufacturing Technology Show Thursday in Chicago.

A stunning variety of participants are visiting the show: Company presidents, chief technology officers, engineers, designers, software developers, entrepreneurs, and college and high school students. This variety showed in the diverse wardrobe: Those in jackets and ties walked the same exhibit halls as those in flip-flops and shorts.

Rahm Emanuel, Chicago’s mayor, showed up to tour the Association for Manufacturing Technology’s Emerging Technology Center, which featured research and development projects from the Oak Ridge National Laboratory. Those projects included a 3D-printed SUV and the “additive bionic human,” showing additive manufactured medical implants and body parts.

Various special focus areas showcased 3D printing/additive manufacturing, machining, controls and CAD/CAM, fabricating and lasers, and more.

At the Proto Labs booth, staffers answered an array of questions, including queries about our new rapid overmolding service, the trend of using 3D printing for production parts, and the finer points of five-axis machining, another new Proto Labs service.