TIPS WITH TONY: Sorting Out Surface Finishes for Stereolithography

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 SL finishing options available at Proto Labs, and when it makes sense to use each.

Unfinished
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.

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

Continue reading

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.

EYE ON INNOVATION: ‘Smart’ Backpack Geared For Travelers, Students

More than 35 million Americans are expected to travel this Labor Day weekend. Plus, more than 77 million schoolchildren and college-age students will be getting ready to return to classrooms. The omnipresent backpack—great for traveling and for students—will likely be along for the ride.

These days, backpacks are doing more than just carrying your stuff. Take the iBackPack, which will enable you to connect to the internet, charge your devices, and track your location.

Photo Courtesy: iBackPack

As Gizmo Times reports, the iBackPack includes:

  • Tesla-style battery systems
  • Personal Wi-Fi hot spot that connects to 3G/4G networks
  • Retractable power USB cord
  • GPS tracking system
  • Bluetooth proximity locator—making it easier to find your bag in airports or other crowded locations
  • Bluetooth speaker system
  • Multiple USB connections to charge multiple devices at once.

Storage compartments abound to keep laptops, smart phones, tablets, and documents secure. Plus, it’s water and abrasion resistant, and TSA- and Department of Transportation-compliant.

Photo Courtesy: iBackPack

The product’s crowdfunding success at Indiegogo has been over the top, with nearly $700,000 raised, which is 892 percent of its original funding goal. Funding also has come from Kickstarter and other sources.

Several models of the product are expected to be available by December, ranging in price from $170-$350.

Eye on Innovation is a monthly look at new technology and products.

 

WEBINAR: How to Choose the Right Thermoplastic with PolyOne

With thousands of thermoplastics on the market, selecting the right material for a run of injection-molded parts can be intimidating. To help make the process more manageable, we’re teaming up with the plastics industry leader, PolyOne, to host a webinar with tips on choosing the right thermoplastic material for your application.

TITLE: Thermoplastics: How to choose the right material for your application
PRESENTER: Jeremy Bland, Technical Dev. Engineer, PolyOne
DATE: Thursday, September 22 at 1 p.m. CDT
REGISTER: Click here to sign up

The presentation will include the following:

  • Factors in thermoplastic material selection
  • Overview of common thermoplastics including the effects of additives
  • An open Q&A session

Busy that day and can’t make it? Not a problem. You can still register and we’ll send a link to a recording that can be watched on-demand. As usual, feel free to forward to a colleague know if you think he or she will be interested in attending.

INDUSTRY SPOTLIGHT: 3D Printing for Production Parts Gains Credibility

Why are some engineers so hesitant to use 3D printing for more than just development?

Engineers are hardwired and trained to make calculated decisions based on facts. Traditional manufacturing processes such as casting and molding have been around a very, very long time—since the Bronze Age—and time has perfected these processes and brought them to what they are today. Both industry experts and novices alike can benefit from hundreds of years of this process evolution. 3D printing processes are relatively new, especially when compared to casting or injection molding.

Motor mounts are among a growing list of automotive parts that are now manufactured using commercial-grade 3D printing.

Modern, commercial-grade printing equipment and processes are capable of predictable results that will ease the mind of the most skeptical engineer. DMLS (direct metal laser sintering) can produce repeatable results for parts that can be manufactured in no other known method. Proto Labs’ 3DP facility is not only ISO 9001:2008, but also AS 9100. This is the supplemental requirement established by the aerospace industry to satisfy DOD, NASA, and FAA quality requirements. This certification should give any engineer a sense of security.

Understanding some basic quality parameters around the processes can help to lay a foundation of credibility. For example, limits are set to the number of times base material can be used, or only virgin powder could be specified. This is no different than controlling the amount of allowable regrind into a plastic injection-molded part.

Rolls-Royce is a notable automaker now using commercial-grade 3D printing for some production parts.

Testing parts to confirm material properties are extremely common in DMLS. Building a standard tensile bar with each build is a great way to confirm batches of production are producing the desired results. This way the first batch can have destructive testing on the tensile bar and parts to confirm the material and process are producing parts with the specified properties. The future batches can test the tensile bar for confirmation the predictable results were achieved.

The aerospace industry has been embracing advanced manufacturing methods for some time now and the automotive industry has also been making great strides in this area. For example, recent articles have been published around the Rolls-Royce Phantom’s printed parts and BMW’s leading spot in adopting printing technologies.