How do you remove the dashboard from a car, intact? Very carefully – especially when the dashboard comes from one of only 19 ever-made vehicles. Here, Bogi Lateiner (at right) and volunteer Ally Abel work to disengage every electrical component, screw and snap-fit connector keeping the S60 T8 Polestar dashboard in place. (Image courtesy PADT Inc.)

Girl Gang Garage Iron Maven Project: Taking Shape, Moving Ahead

The two cars have become one! The body of the 1961 Volvo PV544 is now welded to the chassis-frame of a new 2019 Volvo S60 T8 Polestar Engineered sedan. (Image courtesy PADT Inc.)
The two cars have become one! The body of the 1961 Volvo PV544 is now welded to the chassis-frame of a new 2019 Volvo S60 T8 Polestar Engineered sedan. (Image courtesy PADT Inc.)

If you’ve been following Girl Gang Garage on LinkedIn or Instagram, you know there’s been a ton of progress on the Iron Maven Volvo-rebuild project since PADT’s last post in July. Back then, most of the work had focused on gutting the 1961 Volvo PV544 body and interior, and PADT was able to capture much of the sheet metal shape and dimensions with its GOM Tscan Hawk 3D scanner. We also started brainstorming various 3D printed parts to enable new component designs produced on Stratasys 3D printers.

Since then, Bogi Lateiner, co-owner of Girl Gang Garage (and TV host of Motortrend’s All Girls Garage and Garage Squad), co-owner Shawnda Williams, and a rotating team of volunteer women have turned their efforts to disassembling the second vehicle: the new 2019 Volvo S60 T8 Polestar Engineered sedan (donated by corporate sponsor Volvo) and merging its chassis with the PV544 body.

Sounds simple, sort of? It might be if it weren’t for the facts that:

  • a) the wheelbase (front-tire center to rear-tire center) of the two cars differs: the PV544 clocks in at 102.5 inches but the S60 is quite a bit longer, at 113 inches.  Also,
  • b) the track width (axle length) differs – this time the PV544 is about 12 inches narrower at the front (51 inches versus 63 inches), which means the Girl Gang team needs to expand both of the front fenders by half that amount to accommodate everything in the engine compartment. And, lastly and conversely,
  • c) the S60 dashboard is so wide that it needs to be reconfigured from 56 inches down to about 50 inches or less, to fit the interior dimensions.

Growing Fenders, Redesigning a Grill

Original PV544 front bumper/grill housing and fenders. It all looks huge, right? But with the track-width difference between this design and that of the new Volvo S60 chassis, the Girl Gang Garage team needs to splice in about twelve more inches, probably incorporated in the fenders. (Image courtesy PADT Inc.)
Original PV544 front bumper/grill housing and fenders. It all looks huge, right? But with the track-width difference between this design and that of the new Volvo S60 chassis, the Girl Gang Garage team needs to splice in about twelve more inches, probably incorporated in the fenders. (Image courtesy PADT Inc.)

The old-school approach to reconstructing the front bumper-grill section and fenders would involve cutting the original sheet metal, shaping new metal splices by eye and tape-measure, and welding everything together with skilled handwork. This time, although the first and last steps still apply, that project becomes a much more precise, and predictable, task thanks to the digital workflow of 3D scanning -> data processing -> CAD design. These steps are now underway and will set the stage for a cool new grill and fenders that will act big but fool the eye just a bit to keep the overall lines intact.

3D scan of passenger-side fender of PV544, ready for conversion to CAD and creative expansion. (Image courtesy PADT Inc.)
3D scan of passenger-side fender of PV544, ready for conversion to CAD and creative expansion. (Image courtesy PADT Inc.)
PV544 front bumper/grill scan data acquired with a GOM Tscan Hawk handheld laser 3D scanner. (Image courtesy PADT Inc.)
PV544 front bumper/grill scan data acquired with a GOM Tscan Hawk handheld laser 3D scanner. (Image courtesy PADT Inc.)

It’s pretty clear that this front-end has seen better days, so the analysis and measurements of the existing surface needed to be carefully analyzed. Donated expertise for this task came from Chris Strong and Hayati Dirim of Rapid Scan 3D, who mapped the scanned mesh onto planes and surfaces that define the current grill-mount opening.

Surface data file created from the PV544 bumper/grill scanned mesh. Note the reference plane constructed along the left side. File conversion and measurements completed by Rapid Scan 3D. (Image courtesy Rapid Scan 3D.)
Surface data file created from the PV544 bumper/grill scanned mesh. Note the reference plane constructed along the left side. File conversion and measurements completed by Rapid Scan 3D. (Image courtesy Rapid Scan 3D.)

This information has been handed off to the CAD support team. Working hand-in-hand with the Girl Gang Garage experts, the team is using Fusion 360 CAD software, donated from Iron Maven sponsor Autodesk, to analyze these defining surfaces and design a new grill in CAD, which we expect will be 3D printed and painted to match the updated (not yet announced) body color from sponsor BASF.

Knowing both the fender and grill/frame exact dimensions also supports the team in defining the connections and shape of the widened fenders.

Critical surfaces and dimensions extracted from the bumper/grill scan, converted into CAD and brought into Autodesk Fusion 360. The four planes define the current limits of the opening for the grill. This information will guide the CAD-layout of the brand-new grill design and also serve as boundary layers that mate up to the expanded fenders. (Image courtesy PADT Inc.)
Critical surfaces and dimensions extracted from the bumper/grill scan, converted into CAD and brought into Autodesk Fusion 360. The four planes define the current limits of the opening for the grill. This information will guide the CAD-layout of the brand-new grill design and also serve as boundary layers that mate up to the expanded fenders. (Image courtesy PADT Inc.)

Dashboard Surgery

cially when the dashboard comes from one of only 19 ever-made vehicles. Here, Bogi Lateiner (at right) and volunteer Ally Abel work to disengage every electrical component, screw and snap-fit connector keeping the S60 T8 Polestar dashboard in place. (Image courtesy PADT Inc.)
How do you remove the dashboard from a car, intact? Very carefully – especially when the dashboard comes from one of only 19 ever-made vehicles. Here, Bogi Lateiner (at right) and volunteer Ally Abel work to disengage every electrical component, screw and snap-fit connector keeping the S60 T8 Polestar dashboard in place. (Image courtesy PADT Inc.)

The brand-new 2019 Volvo S60 T8 Polestar Engineered sedan was almost too cool to cut up – but Girl Gang Garage knew that something even better would emerge in the end. Before the roof was cut off (see the video on LinkedIn), the work timeline required removing the dashboard with all its electronic components.

Here’s the extracted S60 dashboard, viewed from the bottom and front:

Volvo S60 Dashboard removed from the car by Girl Gang Garage, to be mounted in the PV544 body of the Iron Maven project. (Image courtesy PADT)

And the frame behind it:

Mounting frame for the original Volvo S60 dashboard. It will need to be retrofitted for the PV544 Volvo rebuild project. (Image courtesy PADT)

And here are the existing red PV544 dash and the black S60 version side by side (the dots are the reflective targets used with the 3D laser scanner). The S60 configuration needs to fit in the original PV544 space. To compress this at least five inches, the glove-box probably has to go.

Both Volvo dashboards side by side: the large new S60 dashboard and the original PV544 dashboard. The new one is more than five inches wider and will have to be cut down. (Image courtesy PADT)

Once again, the team is turning to scan data, and that analysis is in process.

Top view of the S60 dashboard, as scanned with the GOM Tscan Hawk 3D scanner. (Image courtesy PADT Inc.)
Top view of the S60 dashboard, as scanned with the GOM Tscan Hawk 3D scanner. (Image courtesy PADT Inc.)

Stay Tuned

Due to the scheduling and travel challenges presented by the ever-shifting COVID scene, Girl Gang Garage has decided to complete the Iron Maven for presentation at the 2022 SEMA Show (highlighting automotive specialty products). This also allows more time for 3D printing the new components which are coming off the Stratasys F370 printer. PADT will be documenting updates and sharing cool photos of this one-of-a-kind project in the months to come.

PADT Inc. is a globally recognized provider of Numerical Simulation, Product Development and 3D Printing products and services. For more information on GOM 3D scanners and Stratasys printers and materials, contact us at info@padtinc.com.

Girl Gang Garage: Custom Car Rebuilds + 3D Scanning + 3D Printing

What do you get when you cross a 1961 Volvo PV544 retro-look car with a sleek 2019 Volvo S60 T8 Polestar Engineered sedan – and why would you ever do that?

You get a custom head-turner hybrid vehicle designed to get people talking, especially about women in automotive trades. That’s because this blended vehicle project is being disassembled, redesigned and rebuilt by an all-female team based at Girl Gang Garage in Phoenix Arizona.

Bogi Lateiner and Shawnda Williams, co-owners of Girl Gang Garage, stand next to the stripped-down body of a 1961 Volvo PV544 that will soon be retrofitted on the chassis of a brand-new 2019 Volvo S60 T8 Polestar Engineered sedan. The rebuild project provides a rare hands-on learning opportunity for women of all ages and skill levels, from around the U.S., to come and learn (or improve) skills in welding, cutting, transmission work, body repair/painting, electronics, upholstery and more. (Image courtesy Girl Gang Garage.)

Girl Gang Garage founder and co-owner, Bogi Lateiner, TV host of Motortrend’s All Girls Garage and Garage Squad shows, is well on the way to transforming these vehicles as the third major public project she has undertaken. Along with co-owner Shawnda Williams, Lateiner offers women of all ages, experiences and skill levels the chance to lend a hand, learn a tool, and possibly discover a new career-path in the automotive trades.

The front showroom of Girl Gang Garage (Phoenix AZ). At the left is the group’s second all-female build dubbed High Yellow 56, displayed at the 2019 SEMA Show. Partially hidden in the center is the first (2017) Girl Gang build, the Chevy Montage with its BMW engine, and at the right is the early-stage PV544 rebuild slated for showing at the 2021 SEMA Show. (Image courtesy PADT Inc.)

Lateiner and Williams apply well-honed old-school skills but have been increasingly interested in the possibilities offered by today’s digital workflow. That’s why early in 2021, after conversations with the fellow re-build team at Kindig-It Custom Car Fabrication, Lateiner reached out to Stratasys to see how they might work together to incorporate 3D printing in the PV544 project.

At Stratasys, Pat Carey, Senior Vice President Americas Products & Solutions, and Allen Kreemer, Senior Strategic Applications Engineer, were immediately onboard with the chance to help Girl Gang Garage move into the digital world while widening their circle of women with automotive skills and interests. They loaned the team an F370 FDM 3D printer and accompanying support-removal SCA tank and offered to supply filament material for a two year try-whatever-you-want time period. Moreover, they pulled together a volunteer team of women across the country who could support the effort on multiple fronts.

Every 3D printer looks better with a cool scooter in front: the Stratasys F370 FDM printer, installed at Girl Gang Garage. (Image courtesy PADT Inc.)

A Virtual Team and a Digital Workflow

The team includes engineers whose day-time jobs have them working at Stratasys, Link3D, Autodesk, Xerox, Collins Aerospace and Ford Motor Company or as independent consultants. Printer installation and local support is handled by PADT Inc, a Stratasys reseller and 3D printing/design/simulation company located just 16 miles away from Girl Gang Garage. In addition, members of Women in 3D Printing offered to coordinate many of the publicity efforts and even sponsor a related design competition targeted at young women in high schools and colleges who are learning CAD skills. (More on that to come.)

During the first few Zoom meetings that introduced Lateiner and Williams to the technical capabilities of the different team members and the printer, the basic rebuild plan was presented: strip the PV544 down to bare metal (removing every mechanical and electrical component), disassemble the S60 down to the chassis, engine, drive-train and hybrid motor system, and figure out how to make the two sections fit!

Traditionally, that workflow depended strictly on the classic tools of the trade, from cutting wheels and a Sawzall to hand-grinders and pneumatic drills. Those components are still coming into play on the current project under the skilled eye of the Girl Gang Garage leaders, but now complementary digital processes are being added.

It Starts with Scanning

Using the GOM Tscan Hawk hand-held 3D laser-line scanner to digitally capture reference points, surface curvature and details on the PV544 body. (Image courtesy PADT Inc.)

PADT recently became a reseller of GOM 3D scanning hardware and software tools, and the timing was perfect to bring the new handheld Tscan Hawk system on-site. Operating with both red-line and blue-line (different wavelength) laser scanners plus stereo cameras, the Tscan Hawk captures millions of spatial 3D-point-coordinates (termed clouds of data) which are converted into a standard STL mesh file format for several end-purposes. The red lasers generate measurements across medium to large surfaces while the blue-wavelength sensors capture fine detail, with accuracy down to 20 microns.

GOM Inspect software records reference points, captures the individual coordinate data and allows interrogation of that data to provide dimensions, such as the distance between the engine frame mounts or the diameter of the hole into which the headlamp fits.

 (Images courtesy PADT Inc.)

These three images show a) the reference-point data that appears on the laptop screen as the shape of the PV544 vehicle’s underside is captured, b) the completed scan showing the 3D details of the as-built sheet metal and c) a report page from GOM Inspect software with dozens of dimensions extracted from the scan, such as the length of the trunk opening and the width of the opening available for the engine mount. The scan data, if exported as an STL file, could be sent directly to a 3D printer – though for this project the team is not printing the full body. Instead, subsets of the scan are being used for reverse engineering, where the data works as the basis for creative design elements to be printed and perhaps painted or plated.

To do so, the scanned data is be brought into a surfacing package such as Geomagic Design X or Innovmetric PolyWorks. Those software tools let users convert the STL mesh into an IGES surface, which can then be brought into a CAD package as the basis for a new solid model.

Not for the real build but as a fun example, here is a possible headlight-rim with the letters “Girl Gang Garage” cut out as a circular repeat pattern, that could be backlit with LEDS to customize the build. The design and dimensions are based on the maximum inscribed circle fitted by the GOM Inspect software inside the given opening. (In future blog posts, we’ll show examples of the CAD team’s actual 3D printing results.)

Scanning has many other purposes and capabilities. If CAD data were available for the actual vehicle, those files could be imported, overlaid on the captured data, and compared, alerting the user to deviations between intended and actual dimensions – a very common use of GOM Inspect software.

Next Steps

Every Thursday through Sunday, volunteer women come to Girl Gang Garage and learn to use cutting tools, welders, sanders and more, making daily progress toward the completed hybrid PV544. (All women are invited to come help and learn, at no cost – just sign up to get involved and get yourself to Phoenix.) Here are a few glimpses into the work as of early April – much more has been done but stay tuned for the next blog post as we show off elements of the S60 sedan, scan data being used for reference, and details of the design contest.

Views of the PV544 Volvo with work underway on a rear fender (also shown as scan data from the Tscan Hawk, with Bogi Lateiner in her Girl Gang Garage location). (Images courtesy PADT Inc.)

PADT Inc. is a globally recognized provider of Numerical Simulation, Product Development and 3D Printing products and services. For more information on Stratasys printers and materials, contact us at info@padtinc.com.

Mini Mechanica clock section of 3D printed Tourbillon Clock at PADT

Three Dimensions of Time: A new, 3D Printed Clock Highlighting PADT’s Additive Capabilities

Tracking time has challenged the human race for centuries, resulting in some of the finest mechanisms ever crafted. From sundials and hourglasses to pocket watches and atomic clocks, we have marked the passage of time with ever-increasing precision. Along the way, we became supremely skilled at creating the requisite gears and springs, as well as the machines to produce them. (If you have a deeper interest in measuring time, one must-read book is Longitude by Dava Sobel.)

This post, however, is about taking clock-making to a new dimension – three dimensions, in fact, using multiple 3D printers to generate not only the gears and structural components but even the watch-spring and winding-key, based on a mechanism called a Tourbillon. Invented around 1800 by Abraham-Louis Breguet, the Tourbillon concept compensates for the effects of gravity on delicate watch-springs when the watch is carried or laid down (varying its orientations), by employing multiple axes.

A traditionally made Tourbillon watch mechanism (watchgecko.com)

An excellent write-up on this concept is on MyMiniFactory, which is also where you’ll find the fascinating design of a 3D-printable Tourbillon clock from a designer called Mechanistic. Check out this mesmerizing video of the clock in action. Mechanistic has previously done other awesome designs and this past Spring did a crowd-funding effort to support printing all the components on a hobby-type 3D printer.

Depending on one’s donation amount, some or all of the intricate clock’s CAD files are downloadable. Recently Justin Baxter, PADT’s senior 3D Printing Service Engineer (with years of hobbyist clock-making under his belt), set out to reproduce the device with a twist. Why not take advantage of all the additive manufacturing systems in use by PADT’s Manufacturing Division, and print at least one component on each?

This approach spans the AM technologies of Fused Deposition Modeling (Stratasys FDM material extrusion), PolyJet (Stratasys material deposition), selective laser sintering (3D Systems SLS polymer powder bed fusion), direct metal laser sintering (EOS DMLS metal powder bed fusion), stereolithography (3D Systems and UnionTech vat SLA photopolymerization) and digital light processing (Stratasys Origin One DLP vat photopolymerization).

The Triple-Axis Tourbillon Mechanical Clock Design

Not all of the clock’s 230 components are 3D printed – metal screws, pins and ball bearings round out the assembly – but Justin is slowly printing all other parts spread across colors, materials and AM technologies. For starters, he has recreated the central first-axis mechanism called the Mini Mechanica; this subset serves well for new users to test out their own systems and parameters ensuring effective dimensional tolerances. The Mini Mechanica part files are also available as a separate free download.

First section of the Mechanist design of a 3D printed, three-axis Tourbillon mechanical clock, printed at PADT based on the downloaded files from MyMiniFactory. (Image courtesy PADT)

Justin’s Mini Mechanica includes the following parts made of ABS (acrylonitrile-butadiene-styrene), each 3D printed on one of our two Stratasys F370 FDM systems:

Part Name
01_Bottom Base
02_Upper_Base
03_Tourbillon_Lower_Cage
04_Tourbillon_Upper_Cage
05_Cage_Bridge
06_Cage_Spacer
07_Ratchet_Post
08_Winder
09_Mainspring
10_Core_Post
11_Impulse_Pin
12_Tourbillon_Ring_Gear
13_Hairspring
14_Balance_Wheel
15_Escape_Fork
16_Escape_Wheel
17_Washer
18_Display_Stand

When finished, here is how that subset will fit into the completed three-axis clock:

Three-axis Tourbillon clock designed for 3D printing by Mechanistic, with part files available by donation on MyMiniFactory (www.myminifactory.com) (MyMiniFactory)

Note: the fully printed clock operates on a 90 minute run-time if a steel spring is employed, and 20 minute run time with a 3D printed (FDM) version. (We’ve seen suggestions for adding a battery.)

For more details on the Triple Axis clock, see the conveniently provided assembly guide: (2) How to build a 3D Printed Triple Axis Tourbillon | Assembly Guide – YouTube.

As the part-builds progress across our other printers and materials, we’ll post an update. Here are a few more components in progress, including the decorative base on the left, which was printed in Nylon 12GS on our SLS powder-bed printer.

In-progress parts 3D printed for the Mechanica Tri-Axis Tourbillon Clock currently being reproduced at PADT. The decorative base at the left was printed in Nylon 12GS on our SLS system; the parts for the MiniMechanica (assembled at the top) and the remaining black and grey parts were printed in ABS and ASA on our Stratasys F370 FDM systems. (Image courtesy PADT Inc.)

PADT Inc. is a globally recognized provider of Numerical Simulation, Product Development and 3D Printing products and services. For more information on Stratasys polymer printers and materials and EOS metal printers, contact us at info@padtinc.com.

The Many Flavors of 3D Printer Maintenance, and Why it’s So Important

Just over a year ago, PADT, like most every other engineering company, shifted rapidly into minimal on-site-operations mode. As the PADT 3D Printing Application Engineer, I worked from home while requesting support from our manufacturing group for running benchmark parts on our Stratasys fused deposition modeling (FDM) filament and PolyJet resin printers.  Whether those parts were created on the F370, F450, F900 or J55 printers, they spanned a wide range of part size, function and material. It was an interesting time, but software tools like GrabCAD Print made remote part set-up possible, and the on-site team kept everything running under some often-challenging conditions.

I’ve been back in the office for about a month, so I’m tending to tasks that were, out of necessity, put on a backburner while our company did high-importance projects such as printing a ton of PPE visor frames. Now it’s time to do some printer maintenance that got a little delayed beyond the recommended run-time schedule.

For our Stratasys J55 full-color PolyJet printer, while all the standard components were cleaned and checked after every print, we stretched the recommendation period for replacing the wiper blade, the roller-waste collector, and both filters in the compact ProAero Air Extractor that contributes to making this printer truly office-friendly. Now I’ve checked those off as done.

Bring in the Printer Maintenance Experts

Other steps should only be done by a professional from the Service Department at your reseller or from Stratasys. When they come on-site to perform Preventive Maintenance for your printer, do you know what goes into this, and the kind of tasks that keep your system humming along?

It’s similar to practicing good automotive ownership: checking the air in your tires, changing the oil every 5,000 miles or so, replacing brake pads before they’re so thin that you have to turn the rotors, etc. Some jobs you do monthly, some yearly and some on general principles to avoid future trouble which inevitably occurs during the critical stage of a project.

Stratasys F450 Print-Head Gantry Assembly (Image courtesy Stratasys)

Here are some of the tasks our PADT service technician performs from the 12-month Preventive Maintenance Checklist for a Stratasys F450 industrial FDM printer:

  • With the printer powered off, clean the canister drives, gantry fans and electronics bay ventilation fans (kind of like cleaning out the ventilation area under the front of your refrigerator – which we all do regularly, right?) Also, inspect the head cable and heat shields, verify X-Y belt tensions, and replace the vacuum filter.
  • With the printer powered on, verify voltage levels, fan speeds and Z-Zero calibration, inspect the flicker brush assemblies and clean and lubricate the Z-axis leadscrew.

When the two-year point rolls around, these tasks are repeated plus another set is added, such as:

  • With the printer off: Replace the filament guide tubes, Kapton seals, X and Y bellows seals, oven lamps, air-pressure regulator diaphragm and all compressed-air system filter elements.
  • With the printer on: Adjust the air pressure and airflow, verify the oven blower operation and perform filament load-time tests.

And at the four-year mark, all of the above are completed plus such tasks as “replace the X and Y belts.” At every service appointment, too, the technician verifies that the current version of the printer control software has been installed, and that the user has the latest application software, whether Insight or GrabCAD Print. All in all, we’re talking more than 50 check points and tasks that keep the printer running smoothly.

High Expectations from Good Maintenance

I have to admit that when I get into my car, I expect the engine to idle smoothly, the air-conditioning to generate chilled-air, and my driveway to be free of oil spots. However, that expectation is only realistic if I or my mechanic has done due diligence with regular inspections and taken action when certain conditions show up. Checking for dirty spark plugs or a cracked distributor cap will maintain engine performance. If the serpentine belt is showing signs of wear, I’d better replace it rather than risk losing both power steering and air-conditioning on some far-off road in the desert on a beastly summer day. And worn rings, pistons or gaskets could all contribute to that oil leak.

And so it goes with 3D printers. First, the importance of avoiding down-time is huge for most manufacturers and factors into both production planning and a smooth workflow for printing prototypes. Second, if you’ve paid for a Stratasys-authorized Service Plan, you get guaranteed response time when something does go wrong (say you accidently melted filament into the print-head because you didn’t mount the tip correctly – life happens). Third, with a PM contract, a trained technician steps you through every aspect of the printer’s operation, inspection and cleaning whether done daily/weekly/monthly by a program engineer or by the system operator.

Stratasys offers three levels of contract service for almost all of its 3D printers, now covering the gamut from FDM and PolyJet to SLA, DLP, and the new Selective Absorptive Fusion (SAF, a polymer powder-bed fusion technology). Those levels are Sapphire, Emerald, and Diamond which can each be purchased for multi-year coverage.

Generally speaking, service offerings include:

  • On-site technical service
  • Spare parts
  • Priority service scheduling
  • Discounted user-training
  • Discounts on printer heads

Customers also win with hardware updates, optional backup printing services, predictable maintenance expenditures for easier budgeting, and more.

It’s not in my budget to buy a new car every year or even every couple of years, so regular, professional automotive inspection and maintenance is critical to me. It is to customers in the additive manufacturing world, too. So, to paraphrase that diamond-jewelry advertisement, “Now you have a friend in the 3D printer business: Stratasys.” Find out more about service contracts and the details of preventive maintenance by contacting 3DPSAL@PADTinc.com.

PADT Inc. is a globally recognized provider of Numerical Simulation, Product Development and 3D Printing products and services. For more information on Stratasys printers and materials, contact us at info@padtinc.com.

Phoenix Children's Hospital 3D printed heart model. (Image courtesy Phoenix Children's Hospital)

Workflow for Creating a 3D Printed Medical Model with Stratasys

For decades in the medical world, surgeons and their professional support teams have relied on X-rays, computed tomography (CT) scans and magnetic resonant imaging (MRI) data when performing their pre-surgical planning approach. These diagnostic tools have been literal lifesavers, yet the resolution and 2D perspective of these images can make it difficult to determine the full details of anatomical geometry. Subtle, critical abnormalities or hidden geometries can go unnoticed when viewing flat films and digital displays.

3D printed heart model produced by Phoenix Children’s Hospital. (Image courtesy Phoenix Children’s Hospital)

With the advent of 3D printing, many surgeons are now using 3D models for both surgical planning and patient communication. While cost is the primary hold-back, such models are seeing increased use. In addition, efforts are underway to quantify the benefits of reduced operating room time/expense and improved patient outcome; see Medical 3D Printing Registry (ACR/RSNA). Supporting this concept are the high-resolution, multi-material PolyJet 3D printers from Stratasys.

But how does the patient’s CT and MRI data become a unique 3D printed model you can hold in your hand? How do you segment out the areas of interest for a particular analysis or surgical model? This blog post describes the necessary steps in the workflow, who typically performs them, and the challenges being addressed to improve the process every step of the way.

Data Acquisition of Patient Anatomy

When we think of imaging throughout the decades, X-ray technology comes to mind. However, classic single 2D images on film cannot be used to drive 3D models because they are qualitative not quantitative. The main options that do work include the series of x-rays known as CT scans, MRI data, and to a lesser extent computed tomography angiography (CTA) and magnetic resonant angiography (MRA). Each approach has pros and cons and therefore must be matched to the proper anatomy and end use.

CT scans comprise a series of x-rays evenly spaced laterally across a particular body section, typically generating several hundred image files. These can be quickly acquired and offer high resolution, however, they do not do well displaying different types of soft tissue, and the process relies on extended exposure to a radiation source.

Sample multiple digital images generated as a CT scan is performed (Image courtesy nymphoenix/Shutterstock.com.)

Typical CT resolution is 500 microns in X and Y directions, and 1mm in Z. This is readily handled by Stratasys printers; for example, the print resolution of the J750 Digital Anatomy Printer is 42 microns in X, 84 microns in Y, and 14 to 27 microns layering in Z, which more than captures all possible scanned features.

Computed Tomography Angiography (CTA) involves the same equipment but uses a contrast agent. With this approach, brighter regions highlight areas with blood flow. This process is superior for showing blood vessels but does not differentiate tissue or bones well.

MRI data is based on a different technology where a strong magnetic field interacts with water in the body. This approach differentiates soft tissue and shows small blood vessels but is more expensive and not effective for capturing bone. Similarly, Magnetic Resonant Angiography (MRA) uses a contrast agent that can track small blood vessels which are important for identifying a stroke but cannot register tissue. MRI scans may also include distracting artifacts and offer poor regional contrast.

A final source of digital imaging data is Positron Emission Tomography (PET). Here, radioactive material is attached to a biologically active area such as cancer; the data obtained with sensors is useful but very local – it does not show surrounding tissue.

Segmentation: Conversion from DICOM to STL format

Whether generated by CT or MRI equipment, anatomic image data is stored in digital files in accordance with the Digital Imaging and Communications in Medicine (DICOM) standard. Two aspects of this standard are relevant to 3D printing medical models: DICOM files include patient-specific, HIPPA-protected information, and the data in the individual images must be merged and converted into a solid model, with the areas of interest defined and partitioned.

Various software packages and services are available that will convert DICOM data into an STL model file (standard format for 3D printer input) while stripping out the personal identifying information. (The latter must be done to comply with HIPPA regulations: never send a DICOM file directly to any service bureau.)

Segmentation involves partitioning a digital image into distinct sets of pixels, defining regions as organ, bone, blood vessel, tumor, etc., then grouping and combining those sub-sections into a 3D model saved as an STL file. Not only does this format offer more meaningful information than a stack of separate images, but it can then be exported for 3D printing.

Example of processed CT scans, combined into a multiple-view 3D visualization and saved as an STL file. (Image courtesy PADT Inc.)

The standard unit of measure for identifying and segmenting the different regions within the combined 3D series of CT scans is a Hounsfield unit. This is a dimensionless value, defined as tissue density/x-ray absorption; for reference, water = zero, a kidney =+40 and bone = +1000.

Human guidance is needed to set threshold Hounsfield levels and draw a perimeter to the area of interest. You can define groups with the same threshold level, cut out certain areas that are not needed (e.g., “mask” the lungs to focus on the spine), and use preset values that exist for common model types. Typically, a radiologist or trained biomedical engineer performs this task, since correctly identifying boundaries is a non-trivial judgement task.

A particularly challenging task is the workflow for printing blood vessels, as opposed to bones or organs. The output from CTA/MRA imaging is the blood pool, not the enclosing vessel. In this case, users need third-party software to create a shell of X thickness around the blood pool shape, then keep both model files (pool and vessel) to guide printing the vessel walls and their internal support structure (which, on the Stratasys J750 Digital Anatomy Printer, is soluble and dissolves out.)

So far, just a few medical segmentation software packages exist:

  • Materialise Mimics Innovation Suite is internationally known for its excellence in image analysis and allows you to write scripted routines for automating repeated aspects of the segmentation tasks. There are also tools for interpreting images with metal artifacts, designing support connections between parts, measuring specified features, and rendering a view of the resulting 3D model.
  • Synopsys Simpleware ScanIP is a 3D image segmentation, processing, and meshing platform that processes data from MRI, CT, and non-medical imaging systems. Simpleware ScanIP removes or reduces unwanted noise in the greyscale images, allows cropping to the area of interest, supports both automated and user-guided segmentation and measuring and includes API scripting. Modules are available for Cardio, Ortho, and Custom solutions.
  • Invesalius 3 is open-source software that can reconstruct CT and MRI data, producing 3D visualizations, image segmentation, and image measurements in both manual and semi-automated modes.
  • Embodi3D/Democratiz3D is an online service that lets you upload a series of CT scans, select a basic anatomy type (bone, detailed bone, dental, muscle, etc.), choose the free medium-to-low resolution or paid high resolution conversion service, and receive the link to an automatically generated STL file. (Users do not interact with the file to choose any masking, measuring, or cropping.) The website also offers downloadable 3D printable models and 3D printing services.

Note that these packages may or may not have some level of 510K FDA clearance for how the results of their processing can be used. Users would have to contact the vendors to learn the current status.

Setting up the STL file for printing

Most of the segmentation software packages give you options for selected resolution of the final model. As with all STL files, the greater the number of triangles, the finer the detail that is featured, but the model size may get too large for reasonable set-up in the printer’s software. You may also find that you still want to edit the model, either to do some hole repairs or smoothing, slice away a section to expose an interior view, or add mechanical struts/supports for delicate and/or heavy anatomy sections. Materialise Magics software will do all of this readily, otherwise, adding a package that can edit STL files or create/merge geometry onto an STL file will be useful.

Medical Modeling software workflow from CT scan to print, for typical Stratasys 3D printed model.

Whoever is setting the file up for printing needs to make a number of decisions based on experience. For Stratasys Connex3, J55, J8-series or J750 Digital Anatomy Printers, the process begins by bringing the file into GrabCAD Print and deciding on an optimized build orientation. Next, colors and materials are assigned, including transparent sections, percentages of transparent colors, and flexible/variable durometer materials, which can be for a single part or a multi-body model.

For the J750 Digital Anatomy Printer in particular, users can assign musculoskeletal, heart, vascular, and general anatomies to each model, then choose detailed, pre-assigned materials and properties to print models whose tactile response mimics actual biomechanical behavior, such as “osteoporotic bone.” (see Sidebar).

I tested out the free online Democratiz3D segmentation service offered by Embodi3D. Following their tutorial, I was able to convert my very own DICOM file folder of 267 CT images into files without patient ID information, generating a single STL output file. I chose the Bone/Detailed/Medium resolution option which ignored all the other visible anatomy then brought the resulting model into the free software Meshmixer to edit (crop) the STL. That let me zero in on a three-vertebrae section of my lower spine model and save it in the 3MF format.

Lastly, I opened the new 3MF file in GrabCAD Print, the versatile Stratasys printer set-up software that works with both FDM (filament) and PolyJet (UV-cured resin) printers. For the former case, I printed the model in ivory ASA on an F370 FDM printer, and for the latter, I was able to assign a creamy-grey color (Red248/Green248/Blue232) to give a bone-like appearance, printing the model on a J55 PolyJet office-environment printer.

GradCAD Print software set-up of 3MF vertebrae model, ready for printing in a user-defined bone color on a Stratasys J55 PolyJet full-color 3D printer. (Image courtesy PADT Inc.)
3D printed vertebrae parts created from CT scans: on left, ABS part from a Stratasys F370 FDM printer; on right, Vero rigid resin material from a Stratasys J55 PolyJet printer. (Image courtesy PADT Inc.)  

Experience helps in producing accurately segmented parts, but more features, such as AI-enabled selections, and more online tutorials are helping grow the field of skilled image-processing health professionals. Clarkson College (Omaha, NE) also recently announced the first Medical 3D Printing Specialist Certificate program.

Reach out to PADT to learn more about medical modeling and Stratasys 3D printers.

PADT Inc. is a globally recognized provider of Numerical Simulation, Product Development and 3D Printing products and services. For more information on Stratasys printers and materials, contact us at info@padtinc.com.

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Sidebar: J750 Digital Anatomy Printer

The Stratasys J750 Digital Anatomy Printer uses PolyJet resin 3D printing technology to create parts that mimic the look and biomechanical response of human tissue, organs and bones. Users select from a series of pre-programmed anatomies then the material composition is automatically generated along with accurate internal structures. Pliable heart regions allow practice with cutting, suturing and patching, while hollow vascular models support training with guide wires and catheters. General anatomy models can replicate encapsulated and non-encapsulated tumors, while bone structures can be created that are osteoporotic and/or include regions that support tapping, reaming and screw insertion.

Currently the Digital Anatomy Printer models present in the range of 80 to 110 Hounsfield Units. Higher value materials are under development which would help hospitals create phantoms for calibrating their CT systems.

Currently available Digital Anatomy Printer   Model/Section Assignments:

Structural Heart:

  • Clot
  • Frame
  • Myocardium
  • Reinforcement
  • Solid Tumor
  • Valve Annulus
  • Valve Chordae
  • Valve Leaflet
  • Valvular Calcification
  • Vessel Wall

General Anatomy:

  • Dense connective tissues
  • Hollow internal organs
  • Solid internal organs
  • Solid Tumor

Blood Vessels:

  • Clot
  • Fixtures
  • Frame
  • Gel Support
  • Inlets
  • Reinforcements
  • Solid Tumor
  • Valve Annulus
  • Valve Leaflet
  • Vascular Calcification
  • Vessel Wall

Musculoskeletal

  • Facet Joints
  • General Bone
  • Intervertebral Discs
  • Ligament
  • Long Bone
  • Nerves
  • Open End
  • Ribs
  • Skull
  • Vertebra

GrabCAD Print (the App): Making Work-from-Home Actually Work

I am so lucky in a zillion ways to be able to work from home while functioning in my position as a 3D Printing Application Engineer for PADT Inc., a Stratasys 3D printer reseller and engineering consulting/manufacturing company in Tempe Arizona.

Three things are making this possible:

1 – Awesome management and co-workers

2 – Great high-speed internet connection

3 – GrabCAD Print software, and more specifically, the GrabCAD Print phone app.            

Of all the apps on my phone, next to my gmail account, this is the app I check most often, because it is so handy!

First off, I can instantly see the status of the nine PADT printers we have on our Tempe network; I can also check other networks and accounts in other locations for which I have permission. That means I know the status of printers I’m running or want to run, and can tell how long someone else’s job is going to take – a very useful bit of information when it comes to telling a customer or our sales group what printer is open for running a part.

For example, this screen tells me:

–  a job is ready to start on our full-color PolyJet Objet500 Connex3,

–  one print just finished on our Fused Deposition Modeling (FDM) Fortus400,

–  my job is 43 percent complete on one of our FDM F370s, and

–  another of my jobs has just begun on the second F370 system.

I can even see that a print got cancelled on our older F250; in this case, I was expecting that, but it’s good information in case I wasn’t. But there is so much more…

Say I want to confirm the file name of what’s running on that first F370, and get some data about its status. I click on that printer’s name and the app shows me this screen:

Now I see that the print has just gotten to layer 2 of 123 slices total, it started at 1:58pm and it will finish at 6:12pm this evening. It also displays the file name of the part and shows that I’m the owner.

If I slide the image of the printer to the left, I then get the camera view, since an F370 has a build-chamber camera that updates about every ten seconds. Because this print had just started, you can’t really see much beside the build plate (brightly lit at the top), but I can come back to that as often as I like to monitor a particularly challenging geometry – say, perhaps a tall thin part where I added some extra support structure.

At this point I can access several more windows. If I click Job Material Usage, I see

This information is useful if I need a reminder of how much model and support material this print will consume.

The next line offers the bigger picture: clicking through, I see how much material remains in each canister, for both the model and support; it also shows what, if any, material is loaded in the second set of bays. Stratasys printers with double bays will do an automatic hot-swap as needed – a nice feature over the weekend or in the middle of the night.

Here’s another possible status screen: a paused build, where I had planned ahead, inserting a Pause Build instruction in the GrabCAD job set-up. In this case, I wanted to stop the part and remove it, to create a sample piece that exposes the hexagram infill I chose for lightweighting. Another reason to pause and resume an FDM print is to add hardware such as a flat washer to reinforce a deep hole.

The GrabCAD Print App also sends me email alerts (with a chime on the phone) when the status of a print job changes, such as the message below telling me the job has indeed paused as planned:

(I don’t get notifications for other people’s jobs, so I don’t get inundated with messages.)

This real-time information lets me keep track of all my print jobs from my 3D Printing Command Center deep in the heart of suburban Phoenix. I can do 98% of what I need to remotely.

Of course, I depend on the engineers in PADT’s Manufacturing group – essential workers who’ve been in the office non-stop throughout this crazy 2020 work-year. They change filament, load clean trays, run calibrations, remove parts, and put finished prints in our Support Cleaning Apparatus tanks (a PADT-developed system spun off to Oryx and OEM’d to Stratasys since 2009.) That step dissolves the soluble support. (For several of the engineering filaments I run, the support is break-away, and my team takes care of that, too.)

The GrabCAD Print App is available as a free download from the Apple app store. And all of this is in addition to how you can view and interact with GrabCAD Print itself from any computer, setting up a part to print as you sit in one city then uploading the print-ready file to a system across the state or across the country.

Got any questions about the app? We’d love to answer them.

PADT Inc. is a globally recognized provider of Numerical Simulation, Product Development and 3D Printing products and services. For more information on Stratasys printers and materials, contact us at info@padtinc.com.

FDM printed part with surface texture added in SolidWorks 2020.

Printing 3D Texture on FDM 3D Printed Parts – it can be done!

While many examples exist of impressive texturing done on 3D printed Stratasys PolyJet printed parts (some wild examples are here), I have to admit it took me a while to learn that true texturing can also be added to Stratasys Fused Deposition Modeling (FDM) parts. This blog post will walk you through adding texture to all faces or some faces of a solid model, ready for FDM printing. You, too, may be surprised by the results.

I know that complex texturing is possible in a graphics sense with such software packages as Rhino, PhotoShop, Blender and more, but I’m going to show you what you can achieve simply by working with SolidWorks, from Rev. 2019 onwards, as an easy starting point. From there, you can follow the same basic steps but import your own texture files.

Example of Stratasys FDM part set up to print with a checkerboard surface texture. (Image courtesy PADT Inc.)
Example of Stratasys FDM part set up to print with a checkerboard surface texture. (Image courtesy PADT Inc.)

SolidWorks Texture Options

First off, let’s clarify some terms. Texture mapping has existed for years and strictly speaking creates a 2D “texture” or pattern. If I were to wrap that imagery around a 3D CAD model and print it on, say, a PolyJet multi-color 3D printer, I’d get a 3D part with a flat or perhaps curved surface decorated with a multi-color “picture” such as a map or a photo of leather. It could conform, but it’s still basically a decal.

A 3D texture instead is more properly referred to as Bump Mapping (not to be confused with …..too late….bit mapping). Bump mapping interprets the color/contrast information of a 2D image such that it renders light and shadow to give the illusion of a 3D part, while remaining in 2D. Taking this concept one step further, 3D CAD software such as SolidWorks can apply rules that convert white, black and grey shades into physical displacements, producing a kind of tessellated topology mapping. This new information can be saved as an STL file and generate a 3D printed part that has physical, tactile variations in material height across its surface. (For a detailed explanation and examples of texture versus bump-mapping, see the GrabCAD Tutorial “Adding Texture to 3D Models.”)

For FDM parts, you’ll get physical changes on the outer surface of the part that appear as your choice of say, a checkerboard, an arrangement of stars, a pebbly look or a series of waves. In the CAD software, you have a number of options for editing that bump map to produce bigger or smaller, higher or lower, finer or coarser variations of the original pattern, prior to saving the model file as an STL file.

Stepping through SolidWorks 3D Texturing

The key to making this option work in SolidWorks 3D CAD software (I’m using SolidWorks 2020), is in the Appearances tab. Here are the steps I’ve taken, highlighting the variety of choices you can make. My example is the Post-It Note holder I described in my PADT blog post about advanced infill options in GrabCAD Print.

  1. Open Post-It note CAD file, select Solid Bodies (left menu) and select Appearances (in the right toolbar).
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  1. Expand Appearances and go all the way down to Miscellaneous, then click to open the 3D Textures folder.
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  1. Scroll down to choose one of the more than 50 (currently) available patterns. Here, I’ve chosen a 5-pointed star pattern.
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  1. I dragged and dropped that pattern onto the part body. A window opens up with several choices: the default is to apply the pattern to all faces:
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However, you can mouse over within that pop-window to select only a single face, like this:

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  1. When you’ve applied the pattern to either all faces or just one or two, you’ll see a new entry in the left window, Appearances, with the subheading: 5-pointed Star. Right-click on those words, and choose Edit Appearance:
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Then the Appearances window expands as follows, opening by default to the Color/Image tab:

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In this pane, if desired, you could even Browse to switch to a different pattern you have imported in a separate file.

  1. Click on Mapping, and you’ll see a number of “thumb wheel” sliders for resizing the pattern either via the wheel, clicking the up/down arrows, or just entering a value.

Mapping: this moves the pattern – you can see it march left or right, up or down. I used it to center the stars so there aren’t any half-stars cut off at the edge.

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Size/Orientation: You can also try “Fit width to selection” or “Fit height to selection,” or experiment with height and width yourself, and even tilt the pattern at an angle. (If you don’t like the results, click on Reset Scale.) Here, I’ve worked with it to have two rows of five stars.

  1. Remember I said that you can also make the pattern higher or lower, like a change in elevation, so that it stands out a little or a lot. To make those choices, go to the Solid Bodies line in the Feature Manager tree, expand it, and click on the part name (mine is Champfer2).

In the fly-out window that appears, click on the third icon in the top row, “3D Texture.” This opens up an expanded window where you can refine the number of triangular facets that make up the shape of the selected texture pattern. In case you are working with more than one face and/or different patterns on each face, you would check the box under Texture Settings for each face when you want to edit it.

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Here is where you can flip the pattern to extend outwards, or be recessed inwards, or, if you brought in a black/white 2D pattern in the first place, you can use this to convert it to a true 3D texture.

I’ll show you some variations of offset distance, refinement and element size, with exaggerated results, so you can see some of the possible effects:

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In this first example, the only change I made from the default was to increase the Texture Offset Distance from 0.010 to 0.200. The stars are extending out quite visibly.

Next, I changed Texture Refinement from 0% to 66.7%, and now you can see the stars more distinctly, with better defined edges:

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Finally, I am going to change the Element size from 0.128 to 0.180in. It made the star edges only slightly sharper, though at the expense of increasing the number of facets from about 24,000 to 26,000; for large parts and highly detailed texturing, the increased file size could slow down slicing time.

  1. To make sure these textured areas print, you have to do one more special step: Convert to Mesh Body. Do this in the Feature Manager by right-clicking on the body, and selecting the second icon in the top row, “Convert to Mesh Body.” You can adjust some of these parameters, too, but I accepted the defaults.
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  1. Lastly, Save the file in STL format, as usual.

At my company, PADT, my favorite FDM printer is our F370, so I’m going to set this up in GrabCAD Print software, to print there in ABS, at 0.005in layers:

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You can definitely see the stars popping out on the front face; too bad you can also see two weird spikes part-way up, that are small bits of a partial row of stars. That means I should have split the face before I applied the texture, so that the upper portion was left plain. Well, next time.

Here’s the finished part, with its little spikes:

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And here’s another example I did when I was first trying out a checkerboard pattern; I applied the texture to all faces, so it came out a bit interesting with the checkerboard on the top and bottom, too. Again, next time, I would be more selective to split up the model.

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NOTE: It’s clear that texturing works much better on vertical faces than horizontal, due to the nature of the FDM layering process – just be sure to orient your parts to allow for this.

For More Information on Texturing

SolidWorks offers a number of tutorials on the texturing set-up process, such as http://help.solidworks.com/2019/english/solidworks/sldworks/c_3d_textures.htm, and Shuvom Ghose at GrabCAD gives even more details about what to expect with this process in his post https://grabcad.com/tutorials/how-to-3d-texture-your-parts-for-fdm-printing-using-solidworks-2019

There will also be a general Stratasys webinar on The Benefits of 3D Printing Physical Textures on July 29 at 9am PT.

Commercial aircraft companies are already adding a pebble texture to flight-approved cosmetic FDM parts, such as covers for brackets and switches that keep them from being bumped. If you try this out, let us know what texture you chose and send us a photo of your part.

PADT Inc. is a globally recognized provider of Numerical Simulation, Product Development and 3D Printing products and services, and is an authorized reseller of Stratasys products. For more information on Stratasys printers and materials, contact us at info@padtinc.com.

The Mini-EUSO (Extreme Universe Space Observatory), now flying in the International Space Station on the Russian Zvezda module. 3D printed brackets made from Stratasys Ultem 9085 holds photo-multiplier sensors in place. (Image courtesy Italian National Institute for Nuclear Physics (INFN))

3D Printing for Space: FDM Materials on Real Missions

UV sensor section of the Mini-EUSO (Extreme Universe Space Observatory) telescope, now flying in the International Space Station on the Russian Zvezda module. The bracket to mount photo-multiplier detectors above the flat focal plane was 3D printed on a Stratasys F450 system from space-qualified Ultem 9085 filament.
 (Image courtesy Italian National Institute for Nuclear Physics (INFN))
UV sensor section of the Mini-EUSO (Extreme Universe Space Observatory) telescope, now flying in the International Space Station on the Russian Zvezda module. The bracket to mount photo-multiplier detectors above the flat focal plane was 3D printed on a Stratasys F450 system from space-qualified Ultem 9085 filament.
(Image courtesy Italian National Institute for Nuclear Physics (INFN))

What a cool time to be involved in space-based projects, from the recent, stunningly successful manned Space X launch that linked up with the International Space Station (ISS), to the phase 1, unmanned Northrop Grumman/Lockheed Martin Artemis OmegA launch planned for a Spring 2021 debut. In between these big-splash projects are the launches of hundreds of small satellites, whether a 227 kg Starlink or a 1 kg CubeSat. (According to the Space Surveillance Network of the United States Space Force, there are more than 3,000 active satellites currently in orbit.)

One common thread that runs through many of these technology achievements is the use of 3D printed polymer parts, not just as manufacturing tools and fixtures but as flight-certified, end-use components. Applications already in use include:

– Enclosures, casings and covers for bus structures, avionics and electrical systems

– Mounting/routing brackets and clips for wire harnesses

– Barrier structures that separate different on-board experiments

The number and variety of these applications may surprise you, particularly as demonstrated with Stratasys fused deposition modeling (FDM) printed parts made from one of two currently selected materials: Ultem 9085 and Antero ESD (Antero 840CN03). (Tune in for the Stratasys webinar on this topic, Thursday, July 23, at 10am CDT, Additive Manufacturing Applications and Materials for Space.)

Tough, lightweight, space-ready materials

If ever an industry needed light-weight parts, it’s the space industry. Every kilogram loaded onto a rocket demands a physics-determined, expensive amount of fuel to create the thrust that will push it against Earth’s gravity. In addition, most components are one-of-a-kind or low volume. No wonder engineers have worked for decades to replace dense metals with effective, lighter weight polymers.

Those polymers must meet stringent requirement for mechanical behavior:

  • High strength-to-weight ratio
  • Heat resistant up to 320F/167C
  • Chemically resistant to various alcohols, solvents and oils
  • Flame-retardant
  • Non-outgassing

Add to this the need to work in a form that is compatible with additive manufacturing, and the number of material options goes down. However, there are two filaments that have made the grade.

Ultem 9085 is a polyetherimide (PEI) thermoplastic developed and marketed in raw form by SABIC. Stratasys uses strict quality control to convert it into filament that runs on its largest industrial printers and also offers a certified grade that includes detailed production test-data and traceable lot numbers.

Stratasys Ultem 9085 parts have been certified and flown on aircraft since 2011 and have been key components in spacecraft beginning in 2013, such as onboard the Northrop Grumman Antares vehicles typically used for resupplying the ISS.  An unusual project that has used Ultem 9085 parts is MIT/NASA Ames Research Center’s Synchronized Position Hold, Engage, Reorient, Experimental Satellites (SPHERES). Various iterations of these colorful nano-satellites (looking like volley-ball-sized dice) have floated inside the ISS since 2006, with an initial goal of testing the algorithms and sensors required to remotely control the rendezvous and docking in weightlessness of two or more satellite-type structures.

Since then many different versions have been built and delivered to the astronauts of the ISS; both high school and college students have been heavily involved in designing experiments that test physical and mechanical properties of materials in microgravity, such as wireless power transfer. In 2014, the “Slosh” project used Ultem 9085 parts to help connect the units to investigate the behavior of fluids such as fuel sloshing between containers.

More recently, in May 2020, Italian researchers at the National Institute for Nuclear Physics (INFN) relied on Ultem 9085 to build several final parts in its ultraviolet telescope that is now operating onboard the ISS. Called the Mini-EUSO (Extreme Universe Space Observatory), this piece of equipment is one element of a multi-component/multi-year study of terrestrial and cosmic UV emissions, and is now mounted in an earth-facing window of the ISS Russian Zvezda module.

Scientists involved in the Mini-EUSO noted that 3D printing saved them a lot of time in the development and manufacturing process of custom brackets that attach photo-multiplier detectors to the top and bottom of the focal surface, permitting modifications even “late” in the design process. Their use also saved several kilograms of upload mass.

The Mini-EUSO (Extreme Universe Space Observatory), now flying in the International Space Station on the Russian Zvezda module. Upper photo: Close-up of the 3D printed Ultem 9085 brackets (in red) used to mount detector units to the top and bottom edges of the focal plane (blue/purple squares). (Image courtesy Italian National Institute for Nuclear Physics (INFN))
Left: 3D printed Ultem 9085 face-plate added to Mini-EUSO detector bracket. Right: Final unit with electronics included, installed in the complete Mini-EUSO instrument housing. (Images courtesy Italian National Institute for Nuclear Physics (INFN))

The Mini-EUSO (Extreme Universe Space Observatory), now flying in the International Space Station on the Russian Zvezda module. Upper photo: Close-up of the 3D printed Ultem 9085 brackets (in red) used to mount detector units to the top and bottom edges of the focal plane (blue/purple squares). Lower left: 3D printed face-plate added to bracket. Lower right: Final unit with electronics included, installed in the complete Mini-EUSO instrument housing. (Images courtesy Italian National Institute for Nuclear Physics (INFN))

Electrostatic Dissipative PEKK: Antero ESD

Although Ultem 9085 has proven extremely useful for many space-based applications, for certain applications even more capability is needed. The search was on for an electrostatic dissipative filament that also displayed great chemical, mechanical and flame/smoke/toxicity properties. NASA Goddard Spaceflight Center became the driving force behind Stratasys’ subsequent development of Antero ESD (Antero 840CN03), a filament based on the already successful Antero 800NA.

Both Antero products are based on polyetherketoneketone (PEKK), a high-strength, chemically resistant material; in addition, the ESD version is loaded with carbon-nanotube chopped fibers providing a moderately conductive “exit path” that naturally dissipates any charge build-up during normal operations. It also prevents powders, dust or fine particles from sticking to the surface.

NASA first flew Antero ESD parts in 2018 in the form of brackets holding fiber optic cables smoothly in place. This was inside the climate-change monitoring satellite called Ice, Cloud and land Elevation Satellite-2 (ICESat-2). The satellite was built and tested by then Northrop Grumman Innovation Systems, now part of Northrop Grumman Space Systems; the instrument itself is called the Advanced Topographic Laser Altimeter System (ATLAS), a space-based LIDAR unit. Built and managed by NASA Goddard Space Flight Center, this satellite monitors such data as changes in polar ice-sheet thickness.

A Stratasys Antero ESD (Antero 840CN03) 3D printed part (the black curved bracket holding fiber-optic cables) is shown toward the back of NASA’s Advanced Topographic Laser Altimeter System (ATLAS) instrument. This device was launched in 2018 and operates onboard the Ice, Cloud and land Elevation Satellite-2 (ICESat-2) satellite. (Image courtesy NASA)

A Stratasys Antero ESD (Antero 840CN03) 3D printed part (the black curved bracket holding fiber-optic cables) is shown toward the back of NASA’s Advanced Topographic Laser Altimeter System (ATLAS) instrument. This device was launched in 2018 and operates onboard the Ice, Cloud and land Elevation Satellite-2 (ICESat-2) satellite. (Image courtesy NASA)

Counting Down for Launch

An even bigger Antero ESD application – bigger in multiple ways – is waiting in the wings for its debut, comprising sections of the Orion module designed and built by Lockheed Martin Space Systems. This spacecraft will eventually carry astronauts to the Moon and beyond as part of NASA’s Artemis program, with the first un-crewed, lunar-orbit launch scheduled for Spring 2021.

The Orion craft’s docking hatch cover is made entirely from sections printed in Antero ESD. Six pie-shaped sub-sections with intricate curves and cut-outs fit together forming a one-meter diameter ring with a central hole. (If Ultem 9085 had been used, the parts would have needed a secondary coating or nickel-plating to deflect static charge, making the Antero ESD option very attractive.)

Ready, set, print, launch!

Overall view and close-up of Orion spacecraft six-piece hatch cover, 3D printed in Stratasys Antero 840CN03, a carbon-nanotube-fiber filled PEKK thermoplastic with ESD properties. The complete cover diameter is approximately one meter. (Image courtesy Lockheed Martin Space Systems)

Overall view and close-up of Orion spacecraft six-piece hatch cover, 3D printed in Stratasys Antero 840CN03, a carbon-nanotube-fiber filled PEKK thermoplastic with ESD properties. The complete cover diameter is approximately one meter. (Image courtesy Lockheed Martin Space Systems)

PADT Inc. is a globally recognized provider of Numerical Simulation, Product Development and 3D Printing products and services, and is an authorized reseller of Stratasys products. For more information on Stratasys printers and materials, contact us at info@padtinc.com.

Top Ten Additive Manufacturing Terms to Know

The world of additive manufacturing, or 3D printing, is constantly evolving. The technology was invented less than 35 years ago yet has come a long way. What began as a unique, though limited, way to develop low-end prototypes, has exploded into a critical component of the product development and manufacturing process with the ability to produce end-use parts for critical applications in markets such as industrial and aerospace and defense.

To help our customers and the larger technology community stay abreast of the changing world of additive manufacturing, we launched a glossary of the most important terms in the industry that you can bookmark here for easy access. To make it easier to digest, we’re also starting a blog series outlining ten terms to know in different sub-categories.

For our first post in the series, here are the top ten terms for Additive Manufacturing Processes that our experts think everyone should know:

Binder Jetting

Any additive manufacturing process that uses a binder to chemically bond powder where the binder is placed on the top layer of powder through small jets, usually using inkjet technology. One of the seven standard categories defined by ASTM International (www.ASTM.org) for additive manufacturing processes.

Digital Light Synthesis (DLS)

A type of vat photopolymerization additive manufacturing process where a projector under a transparent build plate shines ultraviolet light onto the build layer, which is against the transparent build plate. The part is then pulled upward so that a new layer of liquid fills between the build plate and the part, and the process is repeated. Digital light synthesis is a continuous build process that does not create distinct layers.

Direct Laser Melting (DLM) or Direct Metal Laser Sintering (DMLS)

A type of powder bed fusion additive manufacturing process where a laser beam is used to melt powder material. The beam is directed across the top layer of powder. The liquid material solidifies to create the desired part. A new layer of powder is placed on top, and the process is repeated. Also called laser powder bed fusion, metal powder bed fusion, or direct metal laser sintering.

Directed Energy Deposition (DED)

An additive manufacturing process where metal powder is jetted, or wire is extruded from a CNC controlled three or five-axis nozzle. The solid material is then melted by an energy source, usually a laser or electron beam, such that the liquid metal deposits onto the previous layers (or build plate) and then cools to a solid. One of the ASTM defined standard categories for additive manufacturing processes.

Fused Deposition Modeling (FDM)

A type of material extrusion additive manufacturing process where a continuous filament of thermoplastic material is fed into a heated extruder and deposited on the current build layer. It is the trademarked name used for systems manufactured by the process inventor, Stratasys. Fused filament fabrication is the generic term.

Laser Powder Bed Fusion (L-PBF)

A type of powder bed fusion additive manufacturing process where a laser is used to melt material on the top layer of a powder bed. Also called metal powder bed fusion or direct laser melting. Most often used to melt metal powder but is used with plastics as with selective laser sintering.

Laser Engineered Net Shaping (LENS)

A type of direct energy deposition additive manufacturing process where a powder is directed into a high-energy laser beam and melted before it is deposited on the build layer. Also called laser powder forming.

Material Jetting

Any additive manufacturing process where build or support material is jetted through multiple small nozzles whose position is computer controlled to lay down material to create a layer. One of the ASTM defined standard categories for additive manufacturing processes.

Stereolithography Apparatus (SLA)

A type of vat photopolymerization additive manufacturing where a laser is used to draw a path on the current layer, converting the liquid polymer into a solid. Stereolithography was the first commercially available additive manufacturing process.

Vat Polymerization

A class of additive manufacturing processes that utilizes the hardening of a photopolymer with ultraviolet light. A vat of liquid is filled with liquid photopolymer resin, and ultraviolet light is either traced on the build surface or projected on it. Stereolithography is the most common form of vat photopolymerization. The build layer can be on the top of the vat of liquid or the bottom. One of the ASTM defined standard categories for additive manufacturing processes.

We hope this new blog series will help to firm up your knowledge of the ever-evolving world of additive manufacturing. For a list of all of the key terms and definitions in the additive manufacturing world, please visit our new glossary page at https://www.3dprinting-glossary.com/. The glossary allows you to search by terms or download a PDF of the glossary in its entirety to use as a reference guide.

We also know that there are a ton of experts in our community with knowledge to share. If you notice a term missing from our glossary or an inaccurate/incomplete description, please visit the suggestions page at https://www.3dprinting-glossary.com/suggest-a-correction-clarification-or-new-term/ and drop us a note.

Subscribe to the PADT blog or check back soon for the next installment in our series of “Top Ten Terms to Know in Additive Manufacturing.” We also welcome your feedback or questions. Just drop us a line at here.

Example of full color part with mapped image, created from 3MF file format brought into GrabCAD Print and printed on a Stratasys PolyJet 3D printer. (Image courtesy GrabCAD)

3MF Printing Format Comes to GrabCAD Print

Example of full color part with mapped image, created from 3MF file format brought into GrabCAD Print and printed on a Stratasys PolyJet 3D printer. (Image courtesy GrabCAD)

Example of full color part with mapped image, created from a 3MF file-format brought into GrabCAD Print and set up to print on a Stratasys PolyJet 3D printer. (Image courtesy GrabCAD)

What is the 3MF format? How does it differ from the standard STL format? And what can you do with it, especially if your 3D printers run GrabCAD Print software from Stratasys?

For most designers, engineers and users involved in 3D printing, regardless of the 3D CAD software you use, you save (convert) your model to print as an STL format file. A lot has been written about it, including a PADT post from back in 2012 – and STL-wise, things really haven’t changed. This format approximates the native CAD solid model as a closed surface comprising small triangles of various shapes and sizes. STL has been the standard since the AM industry began, and although different CAD packages use different algorithms to create the mesh, for the most part, it’s worked pretty well.

A Sample STL File Segment

However, an STL file is simply a large text file listing the Cartesian coordinates for each vertex of the thousands of triangles, along with info on the normal direction:

Sample code from saving a CAD model in STL format.

A modest number of large triangles produces relatively small files but doesn’t do a good job of reproducing curves (think highly faceted surfaces); conversely, big files of many small triangles produce much smoother transitions but can take a long time to process in slicing software.

And, perhaps the biggest negative is that an STL file cannot include any other information: desired color, desired material, transparency, internal density gradient, internal fine structure or more.

What is 3MF?

In early 2015, Microsoft and a number of other major corporations including Autodesk, Dassault Systèmes, HP, Shapeways and SLM Group created a consortium to address these issues. They decided to overhaul a little-used file format called the 3D Modeling Format (3MF), to make it support highly detailed 3D model information and be more useful for 3D printing and related processes.

Logo 3MF Consortium

This ongoing consortium project defines 3MF as “a set of conventions for using XML to describe the appearance and structure of 3D models for the purpose of manufacturing (3D printing).”

In developer language, 3MF is a standard package or data that follows a core specification and may include some task-specific extensions.

In user terms, a 3MF file contains some or all of the following information in ASCII format:

  • Metadata about part name, creator and date
  • Information on the mesh of triangles (yes, it still creates and uses these, but does it better for a number of reasons, one of which is that it cannot create non-manifold edges (i.e., triangles that share endpoints with more than one triangle, which confuses the printer))
  • Color information (throughout the complete part body or in sub-sections)
  • Ways to define multiple materials combined as a composite
  • Texture information – what it is and where to place it
  • Ways to assign different materials to different sections of a part
  • Ways to duplicate information from one section of a part to another section, to save memory
  • Slicing instructions

Without getting into the nitty gritty, here are just two examples of XML code lines from 3MF metadata sections:

Example code of saving a solid CAD model in 3MF format.

Meaning, information about the part number and the part color rides along with the vertex coordinates! For a deep-dive into the coding schema, including a helpful glossary, see the 3MF github site; to learn how 3MF compares to STL, OBJ, AMF, STEP and other formats, check out the consortium’s About Us page.

Exporting 3MF Files

Now, how about using all of this? Where to start? Many 3D CAD software packages now let you save solid models as 3MF files (check out your “Save As” drop-down menu to verify), but again, they can vary as to what information is being saved. For example, a SolidWorks 3MF file can generate data on color and material but does not yet support transparency.

Here are all the options that you see in SolidWorks when you click the arrow next to “Save As”:

Second step in SolidWorks for saving a file in 3MF format: check off “include materials” and “include appearance.” (Image courtesy PADT)

“Save As” window in SolidWorks 2019, where step number one is to select “.3mf” format. (Image courtesy PADT)

You can select “.3mf” but don’t Save yet. First, click on the “Options” button that shows up below the Save as File Type line, opening this window:


Second step in SolidWorks for saving a file in 3MF format: check off “include materials” and “include appearance.” (Image courtesy PADT)

You need to check the boxes for “Include Materials” and “Include Appearances” to ensure that all that great information you specified in the solid model gets written to the converted file. A good, short tutorial can be found here.

Another interesting aspect of 3MF files is that they are zipped internally, and therefore smaller than STL files. Look at the difference in file size between the two formats when this ASA Omega Clip part is saved both ways:

Comparison of file size for STL versus 3MF formats.

The 3MF-saved file size is just 13% the size of the standard STL file, which may be significant for file manipulation; for files with a lot of detail such as texture information, the difference won’t be as great, but you can still expect to save 30 to 50%.

Working with 3MF files in GrabCAD Print

Okay, so CAD programs export files in 3MF format. The other half of the story addresses the question: how does a 3D printer import and use a 3MF file? Developers of 3D printing systems follow these same consortium specifications to define how their software will set up a 3MF file to print. Some slicers and equipment already act upon some of the expanded build information, while others may accept the file but still treat it the same as an STL (no additional functions enabled so it ignores the extra data). What matters is whether the system is itself capable of printing with multiple materials or depositing material in a way that adds color, texture, transparency or a variation in internal geometry.

GrabCAD Print (GCP), the cloud-connected 3D Printer interface for today’s Stratasys printers – both FDM and PolyJet – has always supported STL and native CAD file import. However, in GCP v.1.40, released in March 2020, GrabCAD has added support for 3MF files. For files created by SolidWorks software, this adds the ability to specify face colors, body colors and textures and send all that data in one file to a PolyJet multi-material, multi-color 3D printer. (Stratasys FDM printers accept 3MF geometry and assembly structure information.)

For a great tutorial about setting up SolidWorks models with applied appearances and sending their 3MF files to GrabCAD Print, check out these step-by-step directions from Shuvom Ghose.

Example of setting up a textured part in SolidWorks, then saving the file in 3MF format and importing it into GrabCAD Print, for printing on a full-color Stratasys PolyJet printer. (Image courtesy GrabCAD)

Example of setting up a textured part in SolidWorks, then saving the file in 3MF format and importing it into GrabCAD Print, for printing on a full-color Stratasys PolyJet printer. (Image courtesy GrabCAD)

At PADT, we’re starting to learn the nuances of working with 3MF files and will be sharing more examples soon. In the meantime, we suggest you download your own free copy of GrabCAD Print to check out the new capabilities, then email or call us to learn more.

PADT Inc. is a globally recognized provider of Numerical Simulation, Product Development and 3D Printing products and services. For more information on Stratasys printers and materials, contact us at info@padtinc.com.

Varied Infill Options for CAD models brought into GrabCAD Print software for 3D Printing. (Image courtesy PADT)

GrabCAD Print Software, Part Two: Simplify Set-ups, Save Time, and Do Cool Stuff You Hadn’t Even Considered

(Edited 3 August 2020 to reflect GrabCAD Print V1.44)

You haven’t really lived in the world of 3D printing until you’ve had a part fail spectacularly due to open faces, self-intersecting faces or inverted normals. Your part ends up looking more like modern art than technical part. Or perhaps the design you have in mind has great geometry but you wish that some parts could have regions that are dense and strong while other regions would work with minimal infill.

In Part One of this blog post about GrabCAD Print software, we covered the basics of setting up and printing a part; now we’ll look at several of the advanced features that save you set-up time and result in better parts.

Behind the Scenes Repairs

Stratasys GrabCAD Print software, available as a free download, is crafted for users setting up solid models for 3D printing on Stratasys FDM and PolyJet printers. Once you’ve started using it, you’ll find one of its many useful advanced features is the automated STL file-repair option.

Imported STL file, with GrabCAD Print ready to automatically repair errors. PADT image.

Most people still create solid models in CAD software then convert the file to the industry-standard STL format before opening it in a given 3D printer’s own set-up software. Every CAD package works a little differently to generate an STL file, and once in a while the geometry just doesn’t get perfectly meshed. Triangles may overlap, triangles may end up very long and very skinny, or the vector that signals “point in” or “point out” can get reversed.

Traditionally, the 3D printer set-up program reacts to these situations by doing one of two things: it prints exactly what you tell it to print (producing weird holes and shifted layers) or it simply refuses to print at all. Both situations are due to tiny errors in the conversion of a solid CAD model to a tessellated surface.

GrabCAD Print, however, gives your file a once-over and immediately flags sections of the model in need of repair. You can see a color-coded representation of all the problem areas, choose to view just some or all, and then click on Automatic Repair. No hand-editing, no counting layers and identifying sections where the problems reside – just a click of the virtual button and all the problem regions are identified, repaired and ready for the next processing steps.

CAD vs. STL: Do So Much More with CAD

GrabCAD Print also uniquely allows users to bring in their models in the original CAD file-format (from SolidWorks, Autodesk, PTC, Siemens, etc.) or neutral formats, with no need to first convert it to STL. For FDM users, this means GrabCAD recognizes actual CAD bodies, faces, and features, letting you make build-modifications directly in the print set-up stage that previously would have required layer-by-layer slice editing, or couldn’t have been done at all.

For example, with a little planning ahead, you can bring in a multi-body CAD model (i.e., an assembly), assemble and group the parts, then direct GrabCAD to apply different parameters to each body. This way you can reinforce some areas at full density then change the infill pattern, layout, and density in other regions where full strength is unnecessary.

Here’s an example of a SolidWorks model intended for printing with a solid lower base but lighter weight (saving material) in the upper sections. It’s a holder for Post-It® notes, comprising three individual parts – lower base, upper base and upper slot – combined and saved as an assembly.

Sample multi-body part ready to bring into GrabCAD Advanced FDM. Image PADT.

Sample multi-body part ready to bring into GrabCAD Advanced FDM. Image PADT.

Here was my workflow:

1 – I brought the SolidWorks assembly into GrabCAD, assembled and grouped all the bodies, selected an F370 Stratasys FDM printer, chose Print Settings of acrylonitrile butadiene styrene (ABS) and 0.010 inches layer height, and oriented the part.

2 -To ensure strength in the lower base, I selected just that section (you can do this either in the model tree or on the part itself) and opened the Model Settings menu at the right. Under Body, I chose Solid Infill.

3 – Next I selected the upper base, chose Hexagram, and changed the Infill Density to 60%.

4 – Lastly, I selected the upper slot section, chose Sparse, and changed the Infill Density to 35%.

5 – With all three sections defined, I clicked on Slice Preview, sliced the model and used the slider bar on the left to step through each section’s toolpath. For the screenshots, I turned off showing Support Material; the yellow bits indicate where seams start (another parameter that can be edited).

Here is each section highlighted, with screenshots of the parameter choices and how the part infill looks when sliced:

Upper base set up in GrabCAD to print as Hexagram pattern, 60% infill; sliced toolpath shown at right. Image PADT.
Upper slot section set up in GrabCAD to print as Sparse pattern, 35% infill; sliced toolpath shown at right. Image PADT.

So that you can really see the differences, I printed the part four times, stopping as the infill got partway through each section, then letting the final part print to completion. Here are the three partial sections, plus my final part:

Lower base (solid), upper base (hexagram) and first part of upper slot (sparse), done as partial prints. Image PADT.
Completed note-holder set up in GrabCAD Print, Advanced FDM mode, weighted toward the bottom but light-weighted internally. Image PADT.
Completed note-holder set up in GrabCAD Print using advanced infill features, weighted toward the bottom but light-weighted internally. Image PADT.

Automated Hole Sizing Simplifies Adding Inserts

But like the old advertisements say, “But wait – there’s more!” Do you use heat-set inserts a lot to create secure connections between 3D printed parts and metal hardware? Planning ahead for the right hole size, especially if you have different design groups involved and fasteners may not yet be decided, this is the feature for you.

Sample part set up for easy insert additions, using Advanced FDM in GrabCAD Print. Image PADT.

Sample part set up for easy insert additions, using advanced, automated hole-resizing features in GrabCAD Print. Image PADT.

In your CAD part model, draw a hole that is centered where you know the insert will go, give it a nominal diameter and use Cut/Extrude so that the hole is at least the depth of your longest candidate insert. Save the file in regular CAD format, not STL. Next bring your part into GrabCAD Print and go to Model Settings in the right-hand menu.

This time, click on Face (not Body) and Select the inner cylindrical wall of your hole. Several options will become active, including Apply Insert. When you check that box, a new drop-down will appear, giving you the choice of adding a heat-set insert, a helicoil insert or creating a custom size. Below that you select either Inch or Metric, and for either, the appropriate list of standard insert sizes appears.

Automatic hole-resizing in GrabCAD Print, for a specific, standard heat-set insert. Image PADT.

Choose the insert you want, click Update in the upper middle of the GrabCAD screen, and you’ll see the hole-size immediately changed (larger or smaller as needed). The new diameter will match the required oversized dimensions for the correct (melted into place) part-fit. You can even do this in a sidewall! (For tips on putting inserts into FDM parts, particularly with a soldering iron, see Adding Inserts to 3D Printed Parts: Hardware Tips.)

Note that this way, you can print the overall part with a sparse infill, yet reinforce the area around the insert to create just the right mass to make a solid connection. The Sliced view will show the extra contours added around each hole.

Sliced view showing insert holes with reinforced walls, done in GrabCAD Print. Image PADT.
Manufacturing notes automatically created in GrabCAD Print when insert holes are resized. Image PADT.

To document the selected choices for whoever will be doing the insert assembly, GrabCAD also generates a numbered, manufacturing-footnote that lists each insert’s size; this information can be exported as a PDF file that includes a separate close-up image of each insert’s location.

GrabCAD Print keeps adding very useful functions. Download it for free and try it out with template versions of the various Stratasys 3D printers, then email or call us to learn more.

PADT Inc. is a globally recognized provider of Numerical Simulation, Product Development and 3D Printing products and services. For more information on Stratasys printers and materials, contact us at info@padtinc.com.

GrabCAD Print Software: Part One, an Introduction

Where are you on your New Year’s resolutions? They often include words such as “simplify,” “organize” and “streamline.” They can be timely reminders to rethink how you do things in both your personal and professional lives, so why not rethink the software you use in 3D Printing?

Preparing a CAD solid model or an STL file to print on a 3D printer requires using set-up software that is typically unique to each printer’s manufacturer. For Flashforge equipment, you use FlashPrint, for Makerbot systems you use MakerBot Print, for Formlabs printers you use PreForm, and so on.

GrabCAD Print software for setting up STL or CAD files to print on Stratasys 3D printers (main screen).
GrabCAD Print software for setting up STL or CAD files to print on Stratasys 3D printers (main screen). Image courtesy PADT.

For printers from industrial 3D printing company Stratasys, the go-to software is GrabCAD Print (along with GrabCAD Print Mobile), developed for setting up both fused deposition modeling (FDM) and PolyJet technologies in new and efficient ways. Often just called GrabCAD, this versatile software package lets you organize and control prints assigned to one of more than 30 printer models, so the steps you learn for one printer transfer directly over to working with other models.

If you’ve previously used Stratasys Catalyst (on Dimension and uPrint printers), you’ll find similarities with GrabCAD, as well as some enhanced functionality. If you’re accustomed to the fine details of Stratasys Insight, you’ll see that GrabCAD provides similar capabilities in a streamlined interface, plus powerful new features made possible only by the direct import of native CAD files.  Additionally, you can access Insight within GrabCAD, combining the best of both traditional and next-generation possibilities.

Simple by Default, Powerful by Choice

GrabCAD lets users select simplified default settings throughout, with more sophisticated options available at every turn. Here are the general steps for print-file preparation, done on your desktop, laptop or mobile device:

1 – Add Models: Click-and-drag files or open them from File Explorer. All standard CAD formats are supported, including SolidWorks, Autodesk, Siemens and PTC, as well as STL. You can also bring in assemblies of parts and multi-body models, choosing whether to print them assembled or not. (Later we’ll also talk about what you can do with a CAD file that you can’t do with an STL.)

2 – Select Printer: Choose from a drop-down menu to find whatever printer(s) is networked to your computer. You can also experiment using templates for printers you don’t yet own, in order to compare build volumes and print times.

3 – Orient/Rotate/Scale Model: Icons along the right panel guide you through placing your model or models on the build platform, letting you rotate them around each axis, choose a face to orient as desired, and scale the part up or down. You can also right-click to copy and paste multiple models, then edit each one separately, move them around, and delete them as desired.

4 – Tray Settings: This icon leads to the menu with choices such as available materials, slice height options, build style (normal or draft), and more; always targeted to the selected printer. These choices apply to all the parts on the tray or build sheet.

5 – Model Settings: Here’s where you choose infill style, infill density (via slider bar), infill angle, and body thickness (also known as shell thickness) per part. Each part can have different choices.

6 – Support Settings: These all have defaults, so you don’t even have to consider them if you don’t have special needs (but it’s where, for example, you would change the self-supporting angle).

7 – Show Slice Preview: Clicking this icon slices the model and gives you the choice to view layers/tool paths individually, watch a video animation, or even set a Z-height pause if you plan on changing filament color or adding embedded hardware.

8 – Print: You’re ready to hit the Print button, sending the prepared file to the printer’s queue.

Scheduling Your Print, and Tracking Print Progress

A clock-like icon on the left-side GrabCAD panel (the second one down, or third if you’ve activated Advanced FDM features) switches the view to the Scheduler. In this mode, you can see a day/time tracking bar for every printer on the network. All prints are queued in the order sent, and the visuals make it easy to see when one will finish and another start (assuming human intervention for machine set-up and part removal, of course).

Scheduling panel in GrabCAD Print, showing status of files printing on multiple 3D printers.
Scheduling panel in GrabCAD Print, showing status of files printing on multiple 3D printers. Image courtesy PADT.

If you click on the bar representing a part being built, a new panel slides in from the right with detailed information about material type, support type, start time, expected finish time and total material used (cubic inches or grams). For printers with an on-board camera, you can even get an updated snapshot of the part as it’s building in the chamber.

Below the Scheduler icon is the History button. This is a great tool for creating weekly, monthly or yearly reports of printer run-time and material consumption, again for each printer on the network. Within a given build, you’ll even see the files names of the individual parts within that job.

Separately, if you’re not operating the software offline (an option that some companies require), you can enable GrabCAD Print Reports. This function generates detailed graphs and summaries covering printer utilization and overall material use across multiple printers and time periods – very powerful information for groups that need to track efficiencies and expenditures.

And That’s Just the Beginning

Once you decide to experiment with these settings, you begin to see the power of GrabCAD Print for FDM systems. We haven’t even touched on the automated repairs for STL files, PolyJet’s possibilities for colors, transparency and blended materials, or the options for setting up a CAD model so that sub-sections print with different properties.

For example, you’ll see how planning ahead allows you to bring in a multi-body CAD model and have GrabCAD identify and reinforce some areas at full density, while changing the infill pattern, layout, and density in other regions. GrabCAD recognizes actual CAD bodies and faces, letting you make build-modifications that previously would have required layer-by-layer slice editing, or couldn’t have been done at all.

Stay tuned for our next blog post, GrabCAD Print Software, Part Two: Simplify Set-ups, Save Time, and Do Cool Stuff You Hadn’t Even Considered, and reach out to us to learn more about downloading and using GrabCAD Print.

PADT Inc. is a globally recognized provider of Numerical Simulation, Product Development and 3D Printing products and services. For more information on Stratasys printers and materials, contact us at info@padtinc.com.

Books on Additive Manufacturing Make the Perfect Holiday Gift, of Course

It took a while for books about Additive Manufacturing to catch up with the industry; now there are at least several dozen from which to choose.
It took a while for books about Additive Manufacturing to catch up with the industry; now there are at least several dozen from which to choose.

Much as we all love and use websites, YouTube videos and blog posts (you’re reading this one, right?), there are still times when there’s nothing like a book, even if you read it on your phone or dedicated device. Books provide data, perspective and pointers to other resources, in a convenient, all-in-one format. You can dive deeply into a subject or get a fascinating overview of topics you may never have known were connected.

For the AM-lover on your holiday shopping list, consider one of the following titles:

3D Printing: Understanding Additive Manufacturing

by Andreas Gebhardt, Julia Kessler, Laura Thurn | Dec. 2018

3D Printing and Additive Manufacturing: Principles and Applications – Fifth Edition of Rapid Prototyping

by Chee Kai Chua and Kah Fai Leong | Nov. 2016

The 3D Printing Handbook: Technologies, design and applications

by Ben Redwood , Filemon Schöffer , et al. | Nov. 2017

Additive Manufacturing (Second Edition)

by Amit Bandyopadhyay (editor) and Susmita Bose (editor) | Oct. 2019

Additive Manufacturing: Applications and Innovations (Manufacturing Design and Technology)

by Rupinder Singh and J. Paulo Davim | Aug. 2018

Additive Manufacturing Change Management: Best Practices (Continuous Improvement Series)

by David M. Dietrich, Michael Kenworthy, Elizabeth A. Cudney | Feb. 2019

Additive Manufacturing: Design, Methods, and Processes

by Steinar Westhrin Killi | Aug. 2017

Additive Manufacturing for the Aerospace Industry

by Francis H. Froes Ph.D. (editor), Rodney Boyer (editor) | Feb. 2019

Additive Manufacturing: Materials, Processes, Quantifications and Applications

by Jing Zhang and Yeon-Gil Jung | May 2018

Additive Manufacturing of Emerging Materials

by Bandar AlMangour (editor) | Aug. 2018

Additive Manufacturing of Metals: From Fundamental Technology to Rocket Nozzles, Medical Implants, and Custom Jewelry (Springer Series in Materials Science)

by John O. Milewski | July 2017

Additive Manufacturing of Metals: The Technology, Materials, Design and Production (Springer Series in Advanced Manufacturing)

by Li Yang, Keng Hsu, Brian Baughman, Donald Godfrey, Francisco Medina (Author), Mamballykalathil Menon, Soeren Wiener | May 2017

Additive Manufacturing Technologies: 3D Printing, Rapid Prototyping, and Direct Digital Manufacturing (2015 Edition)

by Ian Gibson (Author), David Rosen (Author), Brent Stucker (Author) | Nov. 2014

NOTE: this was the first book written about the field that I could find, with its first edition in 2009. (If you know of one pre-2009, I’d be interested to hear about it.) SME uses this book as the reference guide for its Certification exams for AM Fundamentals and AM Technicians.

Design for Additive Manufacturing: Tools and Optimization (Additive Manufacturing Materials and Technologies)

By Martin Leary | Nov. 2019

Design for Additive Manufacturing: Guidelines for cost effective manufacturing

by Tom Page | Jan. 2012

Design, Representations, and Processing for Additive Manufacturing (Synthesis Lectures on Visual Computing: Computer Graphics, Animation, Computational Photography, and Imaging)

by Marco Attene, Marco Livesu, et al. | June 2018

Laser-Based Additive Manufacturing of Metal Parts: Modeling, Optimization, and Control of Mechanical Properties (Advanced and Additive Manufacturing Series)

by Linkan Bian (editor), Nima Shamsaei (editor), John Usher (editor) | Aug. 2017

Laser Additive Manufacturing: Materials, Design, Technologies, and Applications (Woodhead Publishing Series in Electronic and Optical Materials Book 88)

by Milan Brandt (editor) | Sept. 2016

Laser Additive Manufacturing of High-Performance Materials

by Dongdong Gu | Apr. 2015

The Management of Additive Manufacturing: Enhancing Business Value (Springer Series in Advanced Manufacturing 2018)

by Mojtaba Khorram Niaki, Fabio Nonino | Dec. 2017

Thermo-Mechanical Modeling of Additive Manufacturing

by Michael Gouge and Pan Michaleris | Sept. 2017

Other books definitely exist that have more of a hobbyist focus. This list comes from my own research and opinions and is not intended to slight any other titles. I’d be interested in expanding the list if you know of other titles with an industrial AM slant.

Happy Holiday reading!

Stratasys 3D Printing Filament: the Quality Behind OEM Sourcing

In 1925, when the automotive industry was rapidly growing in response to consumer and industrial needs, a group of independent auto parts resellers joined to form the National Automotive Parts Association (NAPA). A founding member was the Genuine Parts Company; this group later acquired a number of other NAPA stores and gave rise to ad campaigns stressing the importance of buying genuine auto parts from a well-known, trusted source.

Stratasys 3D printing filament is crafted to stringent standards, ensuring dimensional consistency and repeatable material properties. Image courtesy PADT.
Stratasys 3D printing filament is crafted to stringent standards, ensuring dimensional consistency and repeatable material properties. Image courtesy PADT.

Following that same philosophy is a good idea for users involved with industrial 3D printing (additive manufacturing/AM). How do you know your part will print consistently, and display measureable, repeatable material properties, if you can’t rely on the consistency of the AM material’s own production?

At PADT, we print the gamut of filament options on our Stratasys industrial 3D printers, from ABS and TPU to production-grade Nylons and certified Ultem ® . As both an authorized AM system reseller and service provider, we count on the quality of the materials we source for ourselves and our customers, so it’s enlightening to get a behind-the-scenes look at the Stratasys filament production-process.

Ingredients Matter

Great recipes start with the finest ingredients, right? It’s no different when you’re producing filament for demanding applications: start with qualified raw materials from reputable sources. Standard Stratasys filament (like ASA and ABS), Engineering Grade materials (including polycarbonate and Nylon 12) and most Support materials are made in Israel at one of the two Stratasys corporate offices, while the High Performance materials such as Nylon 12 Carbon-Fiber (CF), Antero and Ultem ® products are produced at the original Minnesota location.

The raw stock for 3D printing filament comes in pellet form. Image courtesy Shutterstock.
The raw stock for 3D printing filament comes in pellet form. Image courtesy Shutterstock.

Stratasys buys polymers in pellet form from chemical suppliers such as France-based Arkema, who blends the proprietary polyethyl ketone ketone (PEKK) base formula for Antero and Antero ESD materials, and SABIC who supplies the raw pellets for Ultem ® -based filaments.

Some pellets are fed directly into the filament production equipment while others are compounded like a custom pharmaceutical: mixed and blended with stabilizers and colorants, extruded as interim-stage filament, cooled and then granulated all over again into new pellet stock. (Given that FDM is an extrusion-based technology, one of the seven standard AM technologies defined by ISO/ASTM52900-15, it’s interesting that extrusion plays a key role in the material production-process itself.)

Polymer Pasta

Whether you’ve made your own fresh pasta or just watched a child crank out endless strings of PlayDoh, you can envision the next steps in filament production, starting with melting the pellets into a viscous liquid resin. Chaffee Tran, Stratasys’ Materials Product Director, explains, “Resin is (then) run through a screw extruder and forced through a die (metal perforated with precision holes), cooled as it comes out, and wound onto spools.” An optical monitor continuously checks for “ovality” of the filament as it moves past, and triggers a stop for anything out-of-round beyond tolerance. If you’ve ever struggled with a printer that jammed because of inconsistent filament diameters, you’ll understand the importance of this process requirement.

Loading bays for Stratasys F370 office-environment FDM 3D Printer. Image courtesy Stratasys.
Loading bays for Stratasys F370 office-environment FDM 3D Printer. Image courtesy Stratasys.

Filament for the Stratasys F123 plug-and-play series of printers is packaged on-site as bagged or boxed spools. Filament for the industrial printers such as the F380cf, F450 and F900 gets loaded into sealed canisters that hold larger volumes in both standard and extended capacity. For all filament types, Tran says, “We have full traceability of our finished products via serial number and manufacturing lots. This can be traced back to production documents, to link back to the production-line settings and batch lots of resin used.”

Canister of Stratasys Ultem® 9085 filament, with production documentation for traceability. Image courtesy Stratasys.

One Step Beyond: Certification

For truly demanding applications, the quality process gets kicked up another notch. Ultem ® 9085 Aerospace and Ultem ® 1010 Certified Grade (CG) are shipped with Certificates of Compliance that confirm the production parameters down to the exact machine type and location where the filament is manufactured. “Certified Ultem ® has a higher sampling rate of finished goods for various filament properties and tighter internal specification,” adds Tran.

This tightly regulated process allows Stratasys to be the only AM company offering material certified by the Aircraft Interior Solution (AIS), a process – developed in collaboration with the National Center for Advanced Materials Performance (NCAMP) – that provides the necessary tools, documentation, and training needed to guide aerospace producers down the aircraft qualification process. In order to meet the requirements aerospace manufacturers face, their parts must not only be made from the AIS certified version of the Stratasys Ultem ® 9085 material, but must also be printed on a certified F900mc Gen II system, in accordance with a string of aerospace standards documents. (For more information see details provided by NCAMP.) That’s what you call Quality Control.

For historical details about the development of standards for qualifying non-metallic materials for aircraft applications, now including the first polymer AM material, download this nine-page document, A Path to Certification:

Today's aircraft increasingly rely on non-metallic component design to save on weight and therefore fuel consumption. Certified Ultem 9085® filament from Stratasys plays a key role in supporting the design and use of 3D printed flight-qualified parts. Image courtesy Stratasys.
Today’s aircraft increasingly rely on non-metallic component design to save on weight and therefore fuel consumption. Certified Ultem 9085® filament from Stratasys plays a key role in supporting the design and use of 3D printed flight-qualified parts. Image courtesy Stratasys.

Even if your part production process is not as stringent as that demanded for the AIS program, you’ll avoid jammed drive-gears and cross-wound spools and get consistent part performance when your Stratasys printers run “genuine Stratasys” filament. Classic ABS, chemically resistant Antero, flexible TPU and new, fine-finish Diran are just some of the materials that will offer you repeatable results. Ask us for more details, and stay tuned as Stratasys launches even more options for true industrial applications.

PADT Inc. is a globally recognized provider of Numerical Simulation, Product Development and 3D Printing products and services. For more information on Stratasys printers and filaments, contact us at info@padtinc.com.

New Options for 3D Printing with Nylon Filament, Including Diran

NOTE 10/28/2019: See updated information regarding Diran extruder heads, below.

Does the idea of 3D printing parts in semi-aromatic polyamides (PA) sound intriguing? Too bad it has nothing to do with making nicely scented models – but it has everything to do with reaping the benefits of the Nylon family’s molecular ring structure. Nylon 6, Nylon 12, carbon-filled Nylon 12 and now a new, smoother Nylon material called Diran each offer material properties well-suited for additive manufacturing on industrial 3D printers.

Stratasys Nylon 12 Battery Box
3D printed Nylon 12 Battery Box. (Image courtesy Stratasys)

Quick chemistry lesson: in polyamides, amine sub-groups containing nitrogen link up with carbon, oxygen and hydrogen in a ring structure; most end up with a strongly connected, semi-crystalline layout that is key to their desirable behaviors. The number of carbon atoms per molecule is one way in which various Nylons (poly-amines) differentiate themselves, and gives rise to the naming process.

Now on to the good stuff. PA thermoplastics are known for strength, abrasion-resistance and chemical stability – useful material properties that have been exploited since Nylon’s discovery at Du Pont in 1935. The first commercial Nylon application came in 1938, when Dr. West’s Miracle Tuft Toothbrush closed the book on boar’s-hair bristle use and let humans gently brush their teeth with Nylon 6 (then called “Exton”) fibers.

Today’s Nylon characteristics translate well to filament-form for printing with Stratasys Fused Deposition Modeling (FDM) production-grade systems. Here’s a look at properties and typical applications for Nylon 6, Nylon 12, Nylon 12 CF (carbon-fiber filled) and Diran (the newest in the Stratasys Nylon material family), as we see their use here at PADT.

When Flexibility Counts

Nylon 12 became the first Stratasys PA offering, filling a need for customized parts with high fatigue resistance, strong chemical resistance, and just enough “give” to support press (friction-fit) inserts and repetitive snap-fit closures. Users in aerospace, automotive and consumer-goods industries print Nylon 12 parts for everything from tooling, jigs and fixtures to container covers, side-panels and high vibration-load components.

3D Printed Nylon 12 bending example. (Image courtesy Stratasys)
3D Printed Nylon 12 bending example. (Image courtesy Stratasys)

Nylon 12 is the workhorse of the manufacturing world, supporting distortion without breaking and demonstrating a high elongation at break. Its ultimate tensile strength in XZ part orientation (the strongest orientation) is 6,650 psi (46 MPa), while elongation at break is 30 percent. Users can load Nylon 12 filament onto a Stratasys Fortus 380mc CF, 450mc or 900mc system.

As evidenced by the toothbrush renaissance, Nylon 6 has been a popular thermoplastic for more than 80 years. Combining very high strength with toughness, Nylon 6 is great for snap-fit parts (middle range of flexing/stiffness) and for impact resistance; it is commonly used for things that need to be assembled, offering a clean surface finish for part mating.

Nylon 6 displays an XZ ultimate tensile strength of 9,800 psi (67.6 MPa) and elongation at break of 38%; it is available on the F900 printer. PADT customer MTD Southwest has recently used Nylon 6 to prototype durable containers with highly curved geometries, for testing with gasoline/ethanol blends that would destroy most other plastics.

Prototype gas-tank made of Nylon 6, printed on a Stratasys system, using soluble support. (Image courtesy MTD Southwest)
Prototype gas-tank made of Nylon 6, printed on a Stratasys system, using soluble support. (Image courtesy MTD Southwest)

Both Nylon 12 and Nylon 6 come as black filament that prints in tandem with a soluble brown support material called SR-110. Soluble supports make a huge difference in allowing parts with internal structures and complicated overhangs to be easily 3D printed and post-processed.

Getting Stronger and Smoother

As with these first two PA versions, Nylon 12CF prints as a black filament and uses SR-110 soluble material for support; unlike those PAs, Nylon 12CF is loaded at 35 percent by weight with chopped carbon fibers averaging 150 microns in length. This fiber/resin combination produces a material with the highest flexural strength of all the FDM Nylons, as well as the highest stiffness-to-weight ratio.

Nylon 12 CF (carbon-filled) 3D printed part, designed as a test brake unit. (Image courtesy Stratasys)
Nylon 12 CF (carbon-fiber filled) 3D printed part, designed as a test brake unit. (Image courtesy Stratasys)

That strength shows up in Nylon 12 CF as a high ultimate XZ tensile strength of 10,960 psi (75.6 MPa), however, similar to other fiber-reinforced materials, the elongation at break is lower than for its unfilled counterpart (1.9 percent). Since the material doesn’t yield, just snaps, the compressive strength is given as the ultimate value, at 9,670 psi (67 MPa).

Nylon 12 CF’s strength and stiffness make it a great choice for lightweight fixtures. It also offers electrostatic discharge (ESD) protection properties better than that of Stratasys’ ABS ESD7, yet is still not quite conductive, if that is important for the part’s end-use. (For more details on printing with Nylon 12 CF, see Seven Tips for 3D Printing with Nylon 12 CF.) The material runs on the Fortus 380mc CF, 450mc or 900mc systems.

Just announced this month, Stratasys’ Diran filament (officially Diran 410MF07) is another black Nylon-based material; it, too, features an infill but not of fibers – instead there is a mineral component listed at seven percent by weight. This filler produces a material whose smooth, lubricious surface offers low sliding resistance (new vocabulary word: lubricious, meaning slippery, with reduced friction; think “lube job” or lubricant).

Robot-arm end printed in Diran, a smooth Nylon-based filament. (Image courtesy Stratasys)
Robot-arm end printed in Diran, a smooth Nylon-based filament. (Image courtesy Stratasys)

This smooth surface makes Diran parts perfect for applications needing a non-marring interface between a tool and a workpiece; for example, a jig or fixture that requires a part to be slid into place rather than just set down. It resists hydrocarbon-based chemicals, displays an ultimate tensile strength of 5,860 psi (40 MPa), and has a 12 percent elongation at break.

Close-up of Diran's smooth surface finish. (Image courtesy Stratasys)
Close-up of Diran’s smooth surface finish. (Image courtesy Stratasys)

(Revised) For the first time, Diran also brings the benefits of Nylon to users of the Stratasys office-environment, plug-and-play F370 printer. The system works with the new material using the same extruder heads as for ABS, ASA and PC-ABS, with just a few material-specific requirements. 

To keep thermal expansion consistent across a model and any necessary supports, parts set up for Diran automatically use model material as support. A new, breakaway SUP4000B material comes into play as an interface layer, simplifying support removal. The higher operating temperature also requires a different build tray, but the material’s lubricious properties (just had to use that word again) make for easy part removal and allow that tray to be reused dozens of times.

Read more about this intriguing material on the Diran datasheet:

and contact PADT to request a sample part of Diran or any of these useful Nylon materials.

PADT Inc. is a globally recognized provider of Numerical Simulation, Product Development and 3D Printing products and services. For more information on Stratasys printers and materials, contact us at info@padtinc.com.