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.
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.
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:
When finished, here is how that subset will fit into the completed three-axis clock:
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.)
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.
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 materialsand EOS metal printers, contact us at firstname.lastname@example.org.
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.
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
Priority service scheduling
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 email@example.com.
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.
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.
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.
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.
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.
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 firstname.lastname@example.org.
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:
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.
– 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 email@example.com.
While many examples exist of impressive texturing done on 3D
printed StratasysPolyJet 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.
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.
Open Post-It note CAD file, select Solid Bodies
(left menu) and select Appearances (in the right toolbar).
Expand Appearances and go all the way down to Miscellaneous, then click to open the 3D Textures folder.
Scroll down to choose one of the more than 50 (currently) available patterns. Here, I’ve chosen a 5-pointed star pattern.
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:
However, you can mouse over within that pop-window to select
only a single face, like this:
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:
Then the Appearances window expands as follows, opening by
default to the Color/Image tab:
In this pane, if desired, you could even Browse to switch to
a different pattern you have imported in a separate file.
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.
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.
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.
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:
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
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.
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.
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:
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
Here’s the finished part, with its little spikes:
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.
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.
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 firstname.lastname@example.org.
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(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.
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.
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
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
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:
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:
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.
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.
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.
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.
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 email@example.com.
Taking risks attempting to capture design intent at the end of the process requires a lot of post-processing (coloring, assemblies, a mix of technologies, etc.) – when it’s too time-consuming, expensive, and late to make changes or correct errors. Stratasys PolyJet 3D printing technology is developed to elevate designs by realizing ideas more quickly and more accurately and taking color 3D Printing to the next level.
By putting realistic models in a designer’s hands earlier in the process, companies can promote better decisions and a superior final product. Now, with the Stratasys J8 Series, the same is true for prototypes. This tried and tested technology simplifies the entire design process, streamlining workflows so you can spend more time on what matters –creating, refining, and designing the best product possible.
PADT is excited to introduce the new StratasysJ826 3D printer
Based on J850 technology, the J826 supplies the same end-to-end solution for the design process and ultra-realistic simulation at a lower price point. Better communicate design intent and drive more confident results with prototypes that realistically portray an array of design alternatives.
The Stratasys J826 3D Printer is able to deliver realism, shorter time to market, and streamlined application thanks to a variety of unique attributes that set it apart from most other Polyjet printers:
High Quality – The J826 can accurately print smaller features at a layer thickness of 14µm to 27µm. As part of the J8 series of printers it is also capable of printing in ultra-realistic Pantone validated colors.
Speed & Productivity – Three printing speed modes (high speed, high quality & high mix) allows the J826 to always operate at the most efficient speed for each print. It can also avoid unnecessary down-time associate with material changeovers thanks to it’s built-in material cabinet and workstation.
Easy to Use – A smooth workflow with the J826 comes from simple integration with the CAD format of your choice, as well as a removable tray for easy clean up, and automated support creation and removal.
Are you ready to learn how the new Stratasys J826 provides the same quality and accuracy as other J8 series printers at a lower cost?
Provide the requested information via the form linked below and one of PADT’s additive experts will reach out to share more on what makes this new offering so exciting for the enterprise design world.
If seeing is believing, holding something this vivid is knowing for sure.
The Stratasys J735 and J750 deliver unrivaled aesthetics to your brightest ideas and boldest ambitions with true, full-color capability, texture mapping and color gradients.
3D print prototypes that look, feel and operate like the finished products in multiple materials and colors without sacrificing time for intricacy and complexity. Better communicate designs with vivid, realistic samples, and save on manual post-processing delays and costs.
Stratasys J735 and J750 printers are PANTONE Validated™
This validation makes the Pantone Matching System (PMS) Colors available for the first time in a 3D printing solution. It provides a universal language of color that enables color-critical decisions through every stage of the workflow for brands and manufacturers. It helps define, communicate and control color from inspiration to realization.
Color matching to Pantone Colors in a single click
GrabCAD Print software provides a quicker, more realistic expression of color in your models and prototypes, saving hours over traditional paint matching or iterative color matching processes.
Adding Pantone color selection increases the color gamut found within the GrabCAD Print Application and simplifies the color selection process
Designers can access the colors directly from GrabCAD Print, selecting Pantone within the Print Settings dialog box. From within this view the user can search for their desired Pantone color or select from the list.
Multiple material selections
This means you can load up to six materials at once, including any combination of rigid, flexible, transparent or opaque materials and their components.
Double the number of print nozzles
More print heads means you can produce ultra-smooth surfaces and fine details with layer thickness as fine as 0.014 mm—about half the width of a human skin cell.
Discover how you can achieve stronger realism and color matching thanks to the Pantone Validation available on the Stratasys J750 & J735.
Contact the industry experts at PADT via the link below for more information:
This post is the eleventh 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 firstname.lastname@example.org or give us a call at 1-800-293-PADT.
When it comes to delivering accurate, robust, and feature-rich additive manufacturing, commonly called 3D Printing, to professional users, one brand of systems stands above all the rest: Stratasys. For over a decade PADT has been a reseller of these outstanding machines in the four-corners states of Arizona, Colorado, New Mexico, and Utah. In fact, our leadership position in the Additive Manufacturing space is built on the foundation of our sales and support history with Stratasys.
Stratasys, The World Leader in Additive Manufacturing
There is one simple reason why Stratasys is the world leader in Additive Manufacturing systems and why so many of our customers keep buying Stratasys systems: They Work. The whole point of 3D Printing is that you can go from a computer model to a real part as quickly and easily as possible. Stratasys has created a complete set of hardware, material, and software to make that happen. For hardware, they offer two additive manufacturing technologies: FDM and PolyJet.
FDM, or Fused Deposition Modeling, is the most common technology because it is reliable, accurate, and builds strong parts. FDM was invented by Stratasys over 25 years ago and still forms the foundation of its product line. It is a layered deposition process that melts a variety of plastics that are then extruded through a nozzle to draw the shape of each layer. From the desktop MakerBot machines to the industry favorite FORTUS 900, there is a machine that works for every need. Recently, we have been selling a large number of F370’s to new and existing customers. FDM systems come in a variety of sizes, speeds, costs, and most importantly, material options. And best of all, the majority of FDM systems come with Stratasys’ patented soluble support material that makes support removal as easy as dropping your part into a cleaning system.
If you need greater refinement, the ability to change material, or color, then PolyJet technology is your ideal solution. The power of PolyJet is that it uses inkjet print heads to deposit tiny dots of liquid material on a build layer. That material is then hardened with an ultraviolet lamp. What is cool is that you can have multiple inkjet print heads and therefore deposit a mix of material within a given layer. This allows you to make parts with very hard, or very soft material in the same build. Or, to mix clear and colors in the same build. Our customers use Polyjet printers to make everything from accurate medical models of organs to molds for plastic injection molding. No other 3D Printing technology is as versatile as the PolyJet machines from Stratasys.
The PADT Sales Experience
Lots of people sell 3D Printers. We know because we have been doing it for over fifteen years. And as the technology has become more popular, more and more people are getting into the industry. Our experience and technically driven sales approach is why customers keep coming to PADT when they have so many choices. Our sales team is not about this month’s sales goal. They are about building, and more often than not, growing our relationship with customers new and old. We are all about understanding what you really want to get done, and then finding the right combination of Additive Manufacturing system, accessories, and software that will make it happen.
That expertise comes from the fact that we have been running a 3D Printing service since 1994. We know the real world of Additive Manufacturing. No other reseller can bring our expertise and experience to your aid.
Support that Goes Above and Beyond
Once you purchase a system, your journey with PADT hits full swing. Our engineers will help you install, train your users, and then be there when you need us for maintenance and repair. Or simply to answer your questions. We recently won a series of competitive situations where customers had a choice of who to hire to support their Stratasys systems. They chose PADT over other solutions for one simple reason: we know what we are doing and we really do care. Our team has driven through snow storms, stayed with machines late into the night, and personally shipped replacement parts just so they could get customer’s machines back online and running as quickly as possible.
Talk to PADT about your Additive Manufacturing Needs
Regardless of what systems you currently have, or if you don’t have any 3D Printing capability in-house, now is the time to talk to PADT. We have never had a better offering of solutions in terms of price, performance, and variety of capability. We are helping universities establish labs, Aerospace companies 3D Print hardware for launch vehicles, and consumer products companies shorten their design cycle. It may be time for you to upgrade or add a new material or technology. Or maybe you just need some accessories to get more out of the equipment you have. Regardless of where you are in your Additive Manufacturing journey, PADT is here to help you get more out of your investment.
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 email@example.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.
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.
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
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 firstname.lastname@example.org.
PADT is excited to introduce the newest polyjet material available from Stratasys, Agilus30! Agilus30 is a superior Rubber-like PolyJet photopolymer family ideal for advanced design verification and rapid prototyping.
Get more durable, tear-resistant prototypes that can stand up to repeated flexing and bending. With a Shore A value of 30 in clear or black, Agilus30 accurately simulates the look, feel and function of Rubber-like products. 3D print rubber surrounds, overmolds, soft-touch coatings, living hinges, jigs and fixtures, wearables, grips and seals with improved surface texture.
Agilus30 has applications in a number of areas, including:
Tooling needing rubber-like characteristics
Overmolding & many more!
Want to know more about PolyJet’s toughest flexible material to date?
Join PADT’s 3D Printing Application Engineer James Barker along with Stratasys Materials Business Manager Ken Burns for a presentation on the various benefits and attributes that Agilus30 has to offer, which machines are compatible with it, and how companies are making use of it’s unique capabilities.
Is PolyJet MED610 truly biocompatible? And what does that mean anyway?
A couple of months ago, our product development team contacted me to see if I could 3D print them a small bio-compatible masking device that was needed for temporary attachment to an invasive device prior to insertion for surgery. That led me to investigate all the different bio-compatible materials we did have access to at PADT on our FDM (Fused Deposition Modeling) and PolyJet machines. Given the tiny size and high detail required in the part, I decided to opt for PolyJet, which does offer the MED610 material that is claimed to be biocompatible. As it so happens, we have an Objet Eden 260V PolyJet machine that has been dedicated to running MED610 exclusively since it’s installation a year ago.
We printed the mask, followed all the post-processing instructions per supplier recommendations (more on that later) and delivered the parts for further testing. And that is when I asked myself the questions at the top of this post.
I set off on a quest to see what I could find. My first stop was the RAPID conference in (May 2016), where the supplier (Stratasys Inc.) had a well-staffed booth – but no one there knew much about MED610 apart from the fact that some orthodontists were using it. I did pick up one interesting insight: one of the engineers there hypothesized that MED610 was not very popular because it was cost-prohibitive since its proper use required machine dedication. I then went to the Stratasys Direct Manufacturing (a service bureau owned by Stratasys) booth, but it turned out they don’t even offer MED610 as a material option for service jobs – presumably because of the low demand for this material, consistent with our own observations.
So I took a step back and began searching for all I could find in the public domain on MED610 – and while it wasn’t much, here is the summary of my findings that I hope help anyone interested in this. I categorize it in three sources of information: claims made by the supplier, published work on in vitro studies and finally, some in vivo animal trials. But first, we must ask…
What does it mean for a Material to be Biocompatible?
A definition by Williams (The Williams Dictionary of Biomaterials, 1999) is in order: “Biocompatibility is the ability of a material to perform with an appropriate host response in a specific application.” So if PolyJet MED610 is to be called biocompatible, we must ask – what application do we have in mind? Fortunately, the supplier has a recommendation.
MED610 was launched by Objet in 2011 (Objet was acquired by Stratasys in 2012) as a biocompatible material, ideal for “applications requiring prolonged skin contact of more than 30 days and short-term mucosal-membrane contact of up to 24 hours“. Stratasys claims that parts printed according to Objet MED610 Use and Maintenance Terms were evaluated for biocompatibility in accordance with standard “DIN EN ISO 10993-1: 2009, Biological Evaluation of Medical Devices-Part 1: Evaluation and testing within a risk management process. This addresses cytotoxicity, genotoxicity, delayed hypersensitivity, and USP plastic Class VI, which includes the test for irritation, acute systemic toxicity and implantation”. Unfortunately, the actual data from the biocompatibility study conducted by Objet have not been made publicly available.
It is important to remember that Stratasys publishes a “Use and Maintenance Terms” document that details the steps needed not just to clean the part after printing, but also on the proper setup of the machine for ensuring best chances of meeting biocompatibility requirements. These are published online at this link and include a 3 hour soak in a 1-percent NaOH solution, a 30 min soak in IPA and multiple water jet rinses, among other steps. In other words, the claimed biocompatibility of MED610 is only valid if these instructions are followed. These steps are primarily driven by the need to completely remove supports and any support-residue, but it is not clear if this is needed if a part can be printed without supports. Given such strong process dependencies, it is only to be expected that Stratasys provide a disclaimer at the end of the document clarifying that the users of their machines are responsible for independently validating biocompatibility of any device they make with MED610.
The next question is: have there been any relevant published, independent studies that have used MED610? In my search, I could only find two instances, which I discuss below.
Primary Human Cells Response (In Vitro)
In a recent (January 2016) study published in the Journal of Medical and Biological Engineering, Schmelzer et al. studied the response of primary human cells to four 3D printed materials in vitro: ABS, PC, PLA and MED610 – the only such study I could find. All samples instead went through a 100% ethanol brief rinse and were washed 5 times with de-mineralized water – this seems like a less stringent process than what the supplier recommends (3 hour 1-percent NaOH solution soak, 30 minutes IPA soak and 10 times waterjet blasting) but was designed to be identical across all the materials tested.
There were some very interesting findings:
Different cells had different responses:
MED610 had the most negative impact on cell viability for keratinocytes (epidermal cells that produce keratin) – and the only material that showed statistically significant difference from the control.
For bone marrow mesenchymal (stem) cells, a different effect was observed: direct culture on ABS and PC showed significant growth (7X compared to control) but MED610 and PLA showed no significant effect
Surface Roughness influences cell attachment and proliferation:
In agreement with other work, the authors showed that while rougher surfaces promote initial cell attachment, subsequent cell proliferation and overall cell numbers are higher on smoother surfaces. The MED610 samples had rougher surfaces than the FDM samples (possibly due to the use of the “matte” finish option) and could be one of the contributors to the observed negative effects on cell viability, along with the leached contents from the specimen.
Glaucoma Drainage Device (In Vivo, Rabbit studies)
The devices were printed on a Connex 350 PolyJet machine, after which the supports were removed from the devices with a water jet and “were repeatedly washed and inspected for consistency and integrity.” Tubes were attached with Silicone adhesive and the entire assembly was then “washed and sterilized with a hospital-grade hydrogen peroxide system before use”. The researchers did not examine the cellular and extracellular reactions in great detail, but did conclude that the reactions were similar between the MED610 device and the more standard polypropylene injection-molded device.
A short video recorded by some of the researchers as part of a Bioprinting course also provides some details into the 3D printing aspects of the work done.
In conclusion, the question I posed at the start of this post (Is PolyJet MED610 truly biocompatible?) is too simplistic. A process and a material together are not sufficient – there are procedures that need to be defined and controlled and further and more importantly, biocompatibility itself has to be viewed in the context of the application and the specific toxicity and interaction demands of that application. And that brings us to our key takeaways:
MED610 is only recommended at best for applications requiring prolonged skin contactof more than 30 days and short-term mucosal-membrane contact of up to 24 hours and there is no data to dispute the suppliers claim that it is biocompatible in this context once all recommended procedures are implemented
The work done by Australian researchers in using PolyJet MED610 for devoloping their Glaucoma Drainage Device in animal trials is perhaps the best example of how this material and the technology can be pushed further for evaluating designs and hypothesis in vivo when really fine features are needed. Stratasys’s FDM PC-ISO or ABS M30i materials, or other FDM extrusion capable materials like PLA, PCL and PLGA may be better options when the resolution allows – but this is a topic for a follow-on blog post.
More in vitro work needs to be done to extend the work done by Schmelzer et al., which suggests that MED610 potentially has leachables that do impact cell viability negatively. Specifically, effects of surface finish (“matte” vs “gloss”) and sterilization on cell viability is a worthwhile follow-on step. In the interim, MED610 is expected to perform well for mucosal membrane contact under 24 hours (and why this is a great technology for dental guides and other temporary in-mouth placement).
If you have any thoughts on this matter or would like to collaborate with us and take advantage of our access to a PolyJet printer that is dedicated to MED610 or other bio-compatible FDM materials, as well as our extensive post-processing and design & analysis facilities, please connect with me on LinkedIn or send us a note at email@example.com and cite this blog post.
Schmelzer, E., Over, P., Gridelli, B., & Gerlach, J. (2016). Response of Primary Human Bone Marrow Mesenchymal Stromal Cells and Dermal Keratinocytes to Thermal Printer Materials In Vitro. Journal of Medical and Biological Engineering, 36, 153-167.
Ross C, Pandav S, Li Y, et al. Determination of Bleb Capsule Porosity With an Experimental Glaucoma Drainage Device and Measurement System. JAMA Ophthalmol.2015;133(5):549-554. doi:10.1001/jamaophthalmol.2015.30.
We wanted to see what 3d printing looked like from the inside of the machine so our new intern, Diserae Sanders, placed a GoPro inside our Connex500 during a print job. The item being printed is a demo bicycle pedal printed in multiple materials.
This video is the first in a series we plan to do on 3D printing. If there is something you would like to see us do a video on, please post it in the comments below.