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. Follow Butterfly Releases for more updates.

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.

3D Printing Infill Styles – the What, When and Why of Using Infill

Have you ever wondered about choosing a plain versus funky infill-style for filament 3D-printing? Amongst the ten standard types (no, the cat infill design is not one of them), some give you high strength, some greatly decrease material use or printing time, and others are purposely tailored with an end-use in mind.

Highly detailed Insight slicing software from Stratasys gives you the widest range of possibilities; the basic versions are also accessible from GrabCAD Print, the direct-CAD-import, cloud-connected slicing software that offers an easy approach for all levels of 3D print users.

A part that is mimicking or replacing a metal design would do best when built with Solid infill to give it weight and heft, while a visual-concept model printed as five different test-versions may work fine with a Sparse infill, saving time and material. Here at PADT we printed a number of sample cubes with open ends to demonstrate a variety of the choices in action. Check out these hints for evaluating each one, and see the chart at the end comparing build-time, weight and consumed material.

Infill choices for 3D printed parts, offered with Stratasys’ GrabCAD Print software. (Image courtesy PADT Inc.)

Basic Infill Patterns

Solid (also called Alternating Raster) This is the default pattern, where each layer has straight fill-lines touching each other, and the layer direction alternates by 90 degrees. This infill uses the most material but offers the highest density; use it when structural integrity and super-low porosity are most important.

Solid (Alternating Raster)

Sparse Raster lines for Sparse infill also run in one direction per layer, alternating by layer, but are widely spaced (the default spacing is 0.080 inches/2 mm). In Insight, or using the Advanced FDM settings in GrabCAD, you can change the width of both the lines and the spaces.

Sparse Double Dense As you can imagine, Sparse Double Dense achieves twice the density of regular Sparse: it deposits in two directions per layer, creating an open grid-pattern that stacks up throughout the part.

Sparse High Density Just to give you one more quick-click option, this pattern effectively sits between Sparse Double Dense and Solid. It lays rasters in a single direction per layer, but not as closely spaced as for Solid.

Hexagram The effect of this pattern looks similar to a honeycomb but it’s formed differently. Each layer gets three sets of raster lines crossing at different angles, forming perfectly aligned columns of hexagons and triangles. Hexagram is time-efficient to build, lightweight and strong in all directions.

Hexagram
Additional infill styles and the options for customizing them within a part, offered within Stratasys Insight 3D printing slicing and set-up software. (Image courtesy PADT Inc.)

Advanced Infill Patterns (via Custom Groups in Insight)

Hexagon By laying down rows of zig-zag lines that alternately bond to each other and bend away, Hexagon produces a classic honeycomb structure (every two rows creates one row of honeycomb). The pattern repeats layer by layer so all vertical channels line up perfectly. The amount of build material used is just about one-third that of Solid but strength is quite good.

Hexagon

Permeable Triangle A layer-by-layer shifting pattern of triangles and straight lines creates a strong infill that builds as quickly as Sparse, but is extremely permeable. It is used for printing sacrificial tooling material (i.e., Stratsys ST130) that will be wrapped with composite material and later dissolved away.

Permeable Triangle

Permeable Tubular This infill is formed by a 16-layer repeating pattern deposited first as eight varying wavy layers aligned to the X axis and then the same eight layers aligned to the Y axis. The resulting structure is a series of vertical cylinders enhanced with strong cross-bars, creating air-flow channels highly suited to tooling used on vacuum work-holding tables.

Permeable Tubular 0.2 Spacing
Permeable Tubular 0.5 Spacing

Gyroid (so cool we printed it twice) The Gyroid pattern belongs to a class of mathematically minimal surfaces, providing infill strength similar to that of a hexagon, but using less material. Since different raster spacings have quite an effect, we printed it first with the default spacing of 0.2 inches and then widened that to 0.5 inches. Print time and material use dropped dramatically.

Gyroid 0.2 Spacing
Gyroid 0.5 Spacing

Schwarz D (Diamond) This alternate style of minimal surface builds in sets of seven different layers along the X-axis, ranging from straight lines to near-sawtooth waves, then flipping to repeat the same seven layers along the Y-axis. The Schwarz D infill balances strength, density and porosity. As with the Gyroid, differences in raster spacing have a big influence on the material use and build-time.

Schwarz Diamond 0.2 Spacing
Schwarz Diamond 0.5 Spacing

Digging Deeper Into Infill Options

Infill Cell Type/0.2 spacing Build Time Weight Material Used
Alternating Raster (Solid) 1 h 57 min 123.77 g 6.29 cu in.
Sparse Double Dense 1 hr 37 min 44.09 g 4.52 cu in.
Hexagon (Honeycomb) 1 h 49 min 37.79 g 2.56 cu in.
Hexagram (3 crossed rasters) 1 h 11 min. 47.61 g 3.03 cu in.
Permeable Triangle 1 h 11 min. 47.67 g 3.04 cu in.
Permeable Tubular – small 2 h 5 min. 43.95 g 2.68 cu in.
Gyroid – small 1 h 48 min. 38.68 g 2.39 cu in.
Schwarz Diamond (D) – small 1 h 35 min. 47.8 g 3.04 cu in.
Infill Cell Type/0.5 spacing Build Time Weight Material Used
Permeable Tubular – Large 1 h 11 min. 21.84 g 1.33 cu in.
Gyroid – Large 57 min. 20.59 g 1.29 cu in.
Schwarz Diamond (D) – Large 58 min. 23.74 g 1.51 cu in.

Hopefully this information helps you perfect your design for optimal strength or minimal material-use or fastest printing. If you’re still not sure which way to go, contact our PADT Manufacturing group: get your questions answered, have some sample parts printed and discover what infill works best for the job at hand.

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

Introducing TPU 92A – The latest FDM material from Stratasys

PADT is excited to announce the release of the latest FDM material from Stratasys: TPU 92A.
Thermoplastic Polyurethane (TPU) is a type of elastomer material, known for its flexibility, resilience, tear resistance, and high elongation. It’s a highly process-able material which makes it ideal for additive manufacturing.
TPU 92A is an elastomeric material that is ideal for prototyping highly functional, large, durable, complex elastomer parts. 

This material brings the benefits of an elastomer to the accurate and easy-to-use F123 3D Printer. Combined with soluble support, it lets you create simple to complex elastomer parts, and through printing on the F123 Series gives product developers more tools to expand their prototyping capabilities with reliable accuracy.
Curious to learn more about the unique properties that make TPU 92A such a great option for prototyping?Schedule a meeting to see the material for yourself.Click the link below to start a conversation with PADT’s resident material experts, in order to discuss the capabilities of this Thermoplastic Polyurethane material, and how your company can benefit from using it.

Don’t miss this unique opportunity, schedule a meeting today!

Getting to Know PADT: 3D Printing Services

This post is the sixth installment in our review of all the different products and services PADT offers our customers. As we add more, they will be available here.  As always, if you have any questions don’t hesitate to reach out to info@padtinc.com or give us a call at 1-800-293-PADT.

If there is one service that most people connect PADT with it is our 3D Printing Services.  We have been making prototypes for companies using this ever-advancing technology since we started the company in 1994. As 3D Printing has become more popular and entered the mainstream even beyond engineering, what 3D Printing means to people has changed as well. Along with that, people’s understanding of exactly what it is we do in this area has drifted a little from what goes on. In this month’s installment of our “Getting to Know PADT” series, we will work to provide insight into what 3D Printing Services are and how they can benefit your company. You can visit www.tristaroffset.com for the best printing company in the New York.

What is “3D Printing” and “3D Printing Services?”

To start, it should be called “Additive and Advanced Manufacturing and Prototyping Services, ” but people search for “3D Printing” so that is what we call it.  3D Printing is the common name for what is technically referred to as Additive Manufacturing, or AM.  Most physical parts are made (manufactured) by casting or shaping material into a shape you want, removing material from stock to get the shapes you want, and/or combining physical parts you get by the other two methods. Instead of these well-proven methods, AM creates a part by building up material one layer at a time.  That is why it is called additive – it adds layers of material to get a shape. Here is an older blog article showing the most common technologies used in AM.

The advantage of this approach is that you just need one machine to make a part, you can go straight from a computer model to that part, and you are not held back by the physical constraints of traditional processes. These features allow anyone to make a part and to make shapes we just could not create before.  At first, we only used it for prototypes before parts were made. Then we started to make tools to make final products, and now 3D Printing is employed to manufacturing end-use parts.

In the world of mechanical engineering, where 3D Printing is heavily used, we call companies that use additive manufacturing to make parts for others 3D Printing Service Bureaus or 3D Printing Service Providers. Therefore, the full process of doing manufacturing using the technology is called: 3D Printing Services.

The critical word in that last sentence is “full.”  Sending a computer model to a 3D Printer is just one of many steps involved in Additive Manufacturing.  When the service is employed correctly, it includes identifying the right type of additive manufacturing to use, preparing the geometry, setting parameters on the machine, printing the parts, removing supports, cleaning the parts, sanding, applying a surface finish treatment, and then inspection and shipping.  Anyone can send a part to a printer; the other steps are what make the difference between simply printing a part, and producing a great part.

What Services does PADT Offer?

Additive Manufacturing covers a wide range of technologies that create parts one layer at a time, using a variety of approaches. Some extrude, some harden, some use an inkjet print head, and still others melt material.  What they have in common is creating solid geometry one layer at a time. Each technology has its own unique set of advantages, and that is why PADT offers so many different 3D Printing technologies for our customers.  Each of these approaches has unique part preparations, machine parameters, and post-printing processes. Each with a unique set of advantages.  The key to success is knowing which technology is best for each part and then executing it correctly.

Currently, PADT’s 3D Printing Services Group makes parts for customers using the following technologies.  Each one listed has a brief description of its advantages.  See our website for more details.

Technology

Abbrv.

Advantages

Fused
Deposition Modeling

FDM

Strong parts

Easy operation

Reliability of systems

Broad material choice

Water soluble supports

Fast

Cost

Polyjet

PolyJet

Multiple materials in a single build

Broad material choices

Custom material choices

Multiple colors in single build

Water soluble supports

Accuracy

Stereolithography

SLA

Part quality

Material options

Speed

Speed

Material properties

Self supporting

Selective
Laser Sintering

SLS

Digital
Light Synthesis

DLS

Speed

Production capable

Surface Finish

Material Choices

Material properties

Orthotropic properties

Direct
Laser Melting (Metal)

DLM

Fully dense metal parts

Accuracy

Speed

Part strength

As a proud reseller for Stratasys systems, we feel strongly that the two primary technologies from Stratasys, FDM and Polyjet, are the best for customers who want to do Additive Manufacturing in-house or as a service provider. When customers need something different, they can come to PADT to take advantage of the unique capabilities found in each technology.

How is 3D Printing with PADT Better?

The difference is in what we know and how to execute the complete process.  As a provider of 3D Printing services for over 23 years, very few people in the industry even come close to the amount of experience that we bring to the table.  We also know product development and traditional manufacturing, so when a customer comes to us with a need, we understand what they are asking to do and why. That helps us make the right recommendation on process, material, and post-processing.

A few differentiators are:

  • We know our machines
  • We know our materials
  • We offer a wide range of plastic and metal materials
  • We understand post-processing
  • We understand support removal (we manufacture the leading support removal system)
  • We understand design and manufacturing
  • In-house machining, painting, and part finishing
  • In-house inspection and quality
  • Employees who are enthusiastic and dedicated to providing the right solution.

In addition to all of these things, PADT also offers On-Demand Manufacturing as a Carbon Production Partner. We combine Carbon’s DLS technology with our existing and proven manufacturing processes to provide low volume manufacturing solutions for plastic components.

We are also always looking at the latest technologies and adding what our customers need.  You can see this with the recent addition of systems from ConceptLaser, Carbon and Desktop Metal systems.

 

Next Steps and Where to Learn More

The very best way to learn more about PADT’s 3D Printing services is to have us print a part. The full experience and the final product will explain why, with so many choices, so many companies large and small count on us for their Additive Manufacturing. If you need to learn more, you can also contact us at 480.813.4884 or rp@padtinc.com.

Here are some links that you may find useful:

 

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Getting to Know PADT: Support Cleaning Apparatus (SCA) Manufacturing and Support

This is the third installment in our review of all the different products and services PADT offers our customers. As we add more, they will be available here.  As always, if you have any questions don’t hesitate to reach out to info@padtinc.com or give us a call at 1-800-293-PADT.

PADT is in the business of helping people who make products.  So most people think of us as a provider of tools and services.  What they do not know is that PADT actually has a few of its own products.  The most successful of these is our line of Support Cleaning Apparatus systems, abbreviated as SCA.  These devices are used to remove soluble support material from parts 3D printed in Stratasys Fused Deposition Modeling Systems. They are robust machines manufactured and serviced by PADT, but sold through the Stratasys worldwide sales channel. As of July of 2017, over 10,800 units have been delivered to Stratasys.

Optimized Performance for Hands-Off Part Cleaning

The Stratasys 3D Printing systems that use Fused Deposition Modeling extrude plastic through a heated nozzle to build parts one layer at a time.  There are actually two nozzles. One puts down the building material and the other a support material that is dissolved in warm water that is slightly base.  The best way to remove that support material is to put it into a warm bath where the part is gently tumbled so that the water can works its way evenly into the part.  Stratasys tried several solutions for a companion washing system and eventually came to PADT and asked if we would try our hand at building a robust and efficient system.

The result was the SCA-1200.  Launched at the end of 2008 it met the design requirements for reliability, part cleaning time, and noise.  Over 7,000 of these systems were shipped and saw heavy usage. In fact, if you have a Stratasys FDM system there is a good chance you have an SCA-1200.  It contained a unique shower head design that was optimized with simulation, and a modular assembly that could be repaired easily in the field.

Based upon the success and lessons learned from the SCA-1200, we released the SCA-1200HT in 2014.  With the same basic form factor, this design replaced the off-the-shelf magnetically coupled pump with a simpler and more reliable custom design from PADT. The new unit also had a more pleasing visual design, several usability enhancements, and a greater temperature range. It has sold over 3,000 units and continues to be a popular system.  The latest release includes a no-temperature setting that allows it to be used to clean Stratasys Polyjet parts.

The success of both system lead to a request to look at building a larger machine that could clean more parts at one time as well as larger parts.  The SCA 3600 has three times the volume but shares many internal parts with the SCA-1200HT.  Both of the new systems are doing well in the field with even better reliability and faster part cleaning times. They are also simpler to debug and repair.

The SCA systems are sold as stand alone devices or are bundled with key Stratasys FDM machines.  You can learn more about them on our SCA page:  www.padtinc.com/sca or you can contact whoever you buy your Stratasys equipment from.

Here is a video for the SCA-1200HT that talks all about what it does:

Practicing what We Preach

One of the most rewarding aspects of designing and manufacturing the SCA family of products was that it forced us to practice what we preach. We talk to companies every day about using simulation, 3D Printing, design for manufacturing, proper product development processes, and many more things needed to get a product right.  With the SCA we were the customer. We had to Walk the Walk or stop talking the talk.

 

It has been a phenomenal experience that has made us even better at helping our customers produce their new products. We used CFD to optimize the gentle agitation design and shower head and worked closely with our vendors to minimize the cost of manufacturing.  The worst part was that when the schedule slipped, we couldn’t blame the customer (only slightly joking).  One of the best set of lessons came from doing the repair and refurbishment of systems that failed. Even though the failure rate was low, we learned a lot and were able to make improvements to future designs. Now when we sit across from a customer and talk about the design, test, and manufacture of their product, we can really say that we understand where they are coming from.

 

 

 

 

 

Learn About the New Stratasys 3D Printers and New Orleans

It was my first time visiting New Orleans. I have heard many stories of how good the food is and how everyone is really nice there so I was excited to visit this city for a business trip. Stratasys Launch 2017! There was some buzz going on about some new FDM printers that Stratasys has been working on and I was really excited to see them and hear what sets them apart from the competition. Rey Chu (Co-Owner of PADT), Mario Vargas (Manager of 3D Printer Sales), Norman Stucker (Account Executive in Colorado), and I (James Barker, Application Engineer) represented PADT at this year’s Launch.

The city did not disappoint! I ate the best gumbo I’ve ever tried. Below is a picture of it with some Alligator Bourbon Balls. The gumbo is Alligator Sausage and Seafood. Sooooo Good!!


My last night in New Orleans, Stratasys rented out Mardi Gras World. That is where they build all the floats for Mardi Gras. They had a few dancers and people dressed up festive. I was able to get a picture of Rey in a Mardi Gras costume.

After dinner at Mardi Gras World, I took Rey and Mario down Bourbon Street one last time and then we went to Café Du Monde for their world famous Beignets. Everyone told me that if I come home without trying the Beignets, then the trip was a waste. They were great! I recommend them as well. Below is picture of Mario and me at the restaurant.

As you can see we had a fun business trip. The best part of it was the unveiling of the new FDM printers! Mario and I sat on the closest table to the stage and shared the table with Scott Crump (President of Stratasys and inventor of FDM technology back in 1988). These new printers are replacing some of Stratasys entry level and mid-level printers. What impressed me most is that they all can print PLA, ABS, and ASA materials with the F370 being able to print PC-ABS. You also can build parts in four different layer heights (.005, .007, .010, and .013”), all while utilizing new software called GrabCad Print.

GrabCad Print is exciting because you can now monitor all of you Stratasys FDM printers from this software and setup queues. What made me and many others clap during the unveiling is that with GrabCad Print you no longer have to export STL files! You can import your native CAD assemblies and either print them as an assembly or explode the assembly and print the parts separately.

      

Everyone wants a 3D Printer that can print parts faster, more accurately and is dependable. You get that with the family of systems! Speed has increased big time, they are twice as fast as the Dimension line of FDM printers. Stratasys has published the accuracy of these new printers to be ±.008” up to a 4 inch tall part and then every inch past 4 inches, you add another .002”. These machines are very dependable. They are replacing the Uprint (Uprint SE Plus is still current), Dimension, and Fortus 250 machines that have been workhorses. Many of our customers still have a Dimension from 2002 when they were first launched. In addition to the 43 existing patents that Stratasys has rolled into this phenomenal product, they have an additional 15 new patents that speaks volumes as to the innovation in these 3D printers.

Stratasys Launch was a blast for me. Seeing these new printers, parts that were printed from them, and understanding why these are the best FDM printers on the market was well worth my time! I look forward to helping you with learning more about them. Please contact me at james.barker@padtinc.com for more information. If you would like to hear my recorded webinar that has even more information about the new F170, F270, and F370, here is the link.  Or you can download the brochure here.

Six Things to Do when Shopping for a 3D Printer

Stratasy-Mojo-3D-Printer-in-Shopping-CartPADT has been in this prototyping business for a while, even before we called the machines that make physical parts directly from computer models a 3D Printer.  When we started it was rapid prototyping and we have purchased maybe a dozen machines for our own use, and sold several hundred to our customers.  As the cost of these systems comes down and the number of people interested in having their own 3D Printer goes up, we thought it would be a good time to share our experience with choosing systems with the community.

Here are six things that every person should do when they are shopping for a 3D printer. Many people also follows tips from Vendel Miniatures for shopping. We even recommend that you write these down and fill out a form before you contact the first vendor.

Thing 1:  Understand What you will use your Parts For

This seems obvious. You would not be looking for a 3D printer unless you knew you needed one and you knew what you needed it for.  But in reality it is very easy to get caught up in how powerful and just plane cool this technology is and you start thinking about what you can do, and you forget what you need to do.  The best way to approach this is to not think about which technology you may end up with, that will point you in one direction or another. Just assume you push a button and a prototype of your part comes out. What would you actually use it for?

The key here is to be honest. If the reality is that your receptionist really likes models of Japanese Anime characters, and you plan on making models of such in an attempt to get her attention, then be honest about that. You need a printer with the detail and perhaps color capability for that. But if you really think about it you probably need one to make patterns for doing custom composite layups, so your use will be very different and the so will the system you need.  She probably will be just impressed with your layup tooling. Well, maybe not but your boss will.

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Our experience tells us that customers often get hung up on features that they get excited about, but when you look at the end use of their prototypes, they really do not need some of those features.  We have seen people buy a machine because it was the only one that did this one thing they got fixated on. But in the end, they only make two prototypes that need it a year and the other 137 prototypes they make are kind of sucky.  Make a list of all the uses and put a guess next to them that shows the percentage of parts that fit into that use.  A typical example would be:

  • 35% Mockups for design reviews
  • 25% Models for the machine shop and vendors to help them plan machining
  • 15% Fixtures for testing
  • 10% Consumer testing and marketing mockups for ad campaigns
  • 10% Fit models to build
  •   5% Other

Thing 2: Benchmark the Machines on your Geometry

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When we run into someone that is unhappy with their 3D Printer, three out of four timeswe find out that it just does not perform like they thought it would.  And if we dig deeper we find out that when they were shopping for a printer, they just looked at parts that the various vendors gave them. Demo parts. They never made a variety of their own typical parts.  This is especially true if they ended up buying a lower cost machine.

Here is a secret of every person selling a 3D Printer, that probably is no secret to you. They pick the demo parts they show you because those parts look really good on their technology. And if you are not closely familiar with the strengths and weaknesses of each technology, there is no way for you to know that the parts they showed you may be the only parts that actually look good on that technology.

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Get four or five parts that are typical parts that you would prototype, and have them made on each technology.  Even if the vendor tells you they can only afford to make one sample part for you (with the cost coming down the margins on these machines is low so few in the business can do a bunch of free parts for every potential sale),  go ahead and pay money to get your geometry made.  You may be shocked by the results, especially on some of the newer low cost machines.

Thing 3: Ignore Hype or the Herd

Any fast growing industry has a lot of hype, and a lot of mob pressure to go with one technology over another.  3D Printing is no different, and in fact it is worse because this technology is so cool and interesting.  The problem with hype and herd mentality is that the company with the best public relations people or with the “hippest” story gets all the attention regardless of the technology. And it feeds on itself. They get more attention because they got more attention.

A case in point is the recent introduction of a hand-held fused deposition modeling system.  Very cool, lots of hype and interest.  But really, who could use that for real work?  Even a hobbyist is going to struggle with making anything useful with a tool like that. But there is a lot of hype around it right now and a huge amount of interest. I’ve had a taxi driver mention it to me when he asked what I do.

It is human nature to want to be part of something big. So it is hard to push that aside and look at each 3D Printer you are evaluating on its own merit. Not what the press is saying, not what other people are touting, not what is the newest and flashiest.  We are talking basic “make me a useable part” here.  Look at it with basic and non-influenced eyes.

Thing 4: Calculate the Total, Long Term Cost

Of all the things listed here, this may be the hardest to do. There are so many costs that go into making prototypes. The initial cost of the machine is small compared to all the other costs. What we recommend you do is make a spreadsheet and list cost items in the first column, and create rows for each 3D Printer you are looking at, then fill it out. We like to put in the cost over three years.

Here are some cost items we recommend people include:

  • System
  • Cleaning system
  • Facility modification costs
  • Build and support material
  • Cleaning materials
  • Maintenance fees
  • Labor to prepare jobs
  • Labor to post process jobs
  • Facility square footage for machines, cleaning equipment, material storage, etc…
  • Scrap rate cost (some systems have a higher scrap rate, you need to include the cost of lost time and material because of that)

Thing 5: Honestly Prioritize the Features you Want and Need

It is always a good idea to make a “want” and “need” list, regardless of what you are purchasing.  When you are dealing with a set of technologies with so much buzz around it, we feel it is doubly important.  Sitting down and making a list, then justifying it to someone else clarifies what you should be looking for more than anything.

We also recommend that you prioritize the list.  Marking things as Want and Need is a first step, then every one of those should also be ranked in order of importance.  You can use a point scheme or you can just put them in order from most to least.  This will help you sort through the gee-whiz stuff and truly understand where the value of your investment in 3D Printing can be found.

Needless to say, it is critical that you finish Thing 1, and refer to it, when completing this step.

Thing 6: Figure Out what is Good Enough, then Ask for More

OK, maybe this one sounds like a sales pitch: “You know what you really want, but really, trust me, you need more.”  Experience tells us that this is actually true. When you are talking 3D Printing we run into customer after customer that felt the system they purchased was “good enough” for their needs then they realize it does not do what they need.  And in most cases it is because they really needed a bigger machine, or they needed a more robust material than they thought.

The last thing you want to do is invest in a 3D Printer then six months later try and turn it in to get one that is bigger, faster, more precise, or that runs a better material.   Now you are still paying for the more expensive system and you wasted money on the less expensive one.  Be honest, upgrade in the beginning to what you really need in the long run not what you think you can get by with in the short run. Because, in the end, you will save money and have better parts.

Doing the Six Things and Getting that 3D Printer

You know you want one. You actually probably need one. We have been doing this for a long time and almost every customer that has made an intelligent investment feels like the investment has been a positive one. And by intelligent investment, we do not want to imply that they bought a system from PADT (although statistically that may be true). What we have found is that these companies took their time, they used some variation of the steps listed above, and they treated their purchase as a long term investment.

You too can make a smart choice and make in-house 3D Printing part of your company, job, or even hobby.  PADT is here ready to help you with that choice.  We can show you the complete line of fused deposition and Polyjet 3D Printers from Stratasys. We can also provide some advice on what we think is a good fit for your needs, and help you capture data for the six things we have outlined here.  And don’t forget, we have a full 3D Printing services offering, with all the major systems and materials. So we can show you the advantages of all of them by providing you with your outsourced parts while you look for an in-house solution.

Stratasys Objet Polyjet Systems

3D Printing Technology Animations

Update: 

We recentlly used these animations for a presentation and realized that this post is so incredibly old that we call everything Rapid Prototyping. In the years since this was written, the industry has shifted to using the terms 3D Printing and Additive Manufaturing.  So we went through and updated it so people can find it easier in search engines. 

Additive Manufacturing has changed a lot since these were made and we do hope to soon update these animations, and add new technologies we did not cover.    – Eric Miller  11/8/2019


Every once in a while we get asked to go out and do presentations on 3D Printing. As part of that, we like to explain the four most common. Additive Manufacturing technologies: SLA, SLS, FDM, and Polyjet. No matter how many hand gestures we use people just don’t seem to get it unless we show an animation.

So we thought it would be good to share those with the community so that they can either learn about the basics of the technology or use these to help educate others. They are crude, we are engineers and not artists.  But they get the point across and should help people understand Additive Manufacturing better.

They are in the form of animated GIF’s, so you can put them on a website or throw them in a PowerPoint and you don’t need a viewer or special software to view them.  Click on the images to get the larger version.  Then right-mouse-button to download to your computer.

Use as you see fit, just remember to mention where you found them: P – A – D – T.

FDM-Animation

PolyJet_Animation

SLA-Animation-3

SLS-Animation