Additive manufacturing (AM) needs tools to manage data to ensure quality, repeatability, traceability, and reliability, especially in the heavily regulated aviation and medical industries.
Throughput Consulting’s Bluestreak | Bright AM™ management execution system (MES)/quality management system (QMS) solution manages AM production and can interface with existing systems to share data. The Bluestreak software portfolio is dedicated to manufacturing process control, work order management, QA/QC, and industry specification adherence.
“Our MES/QMS solution is a unified system contained within an all-encompassing MS SQL Server database that is equipped to manage data and give real-time visibility into the production environment, and it eliminates confusing paper trails and disparate silos of redundant data,” says Todd Wenzel, President and CTO, Throughput Consulting Inc.
The software supports:
Unique serialization for build traceability throughout a product’s life cycle, even if multiple parts with different serial numbers are printed on the same build plate.
Advanced dispositioning to manage nonconformances, scrap disposition, and the ability to allow parts to go down different processing paths without breaking the audit trail.
Ron Beltz, Director of Strategic Accounts, says AM “machines have gotten faster and more predictable; materials have gotten better; design and prototype software solutions have advanced. But one of the remaining hurdles – and one that individual companies are often working out for themselves – is standardization. How do you ensure predictable parts in a process that has so many parameters?”
The U.S. Air Force Research Laboratory, Boeing, and Thermwood partner on a low-cost responsive tooling program using large-scale, polymer-based additive manufacturing.
Boeing responded with a submission on ManTech’s Open broad-agency announcement (BAA) to evaluate the current state of additive manufacturing (AM) technology with respect to fabricating low-cost, autoclave-capable tools. The initial demo tool is for an AFRL concept aircraft fuselage skin.
Boeing contracted Thermwood to demonstrate its large-scale additive manufacturing (LSAM) machine with vertical lay print (VLP) capability. VLP AM reduces costs by increasing the size that components can be printed, reducing assembly cost for large tools.
Mid-scale tool 3D printing on large-scale additive manufacturing (LSAM).
To validate the LSAM VLP process using high-temperature autoclave-capable materials, Boeing and AFRL chose to 3D print a section of the large tool. The mid-scale tool was printed on Thermwood’s LSAM AM demonstration machine in Indiana using a 40mm print core running 25% carbon fiber-reinforced polyethersulfone (PESU).
The initial test tool has the same width, height, and bead path as the final mold and incorporates all major features of the final mold – but was compressed in length to 4ft. The final tool will be more than 10ft. The mid-scale tool was the first high-temperature tool printed using the VLP system.
The mid-scale tool required 5 hours, 15 minutes to print and weighed 367 lb. After final machining, the tool passed room temperature vacuum testing and achieved dimensional surface profile tolerances.
The next step in the program is for production of a full-size 1,400 lb tool that will required 18 hours to print.
Boeing and the Air Force are carefully documenting all operational parameters with hopes of transitioning the technology to production programs. AM autoclave tooling offers significant advantages over traditional production methods – primarily lower cost and fabrication in days or weeks rather than months.
AFRL is very interested in tooling approaches for the Low-Cost Attritable Technology (LCAAT) program, which targets breaking the cost growth curve to field new systems faster.
AFRL Program Manager Andrea Helbach says, “We are interested in additively manufactured tooling’s ability to reduce the cost and time to procure autoclave-capable tooling. Additionally, AM tooling supports changes in vehicle design with minimal non-recurring expenses.”
“Future fielded low-cost, but capable unmanned aerial vehicles (UAVs) will need a responsive materials and manufacturing processes strategy,” says Craig Neslen, LCAAT initiative manufacturing lead. “Additive manufactured composite tooling is one of many technologies being evaluated to ensure the industrial base can handle future manufacturing surge requirements as well as accommodate periodic system tech refresh activities which could necessitate minor vehicle design changes at an acceptable cost.”
Many orthopedic implant companies claim their technologies facilitate bone ingrowth (or allow bone growth). Little clinical evidence backs up these claims, other than titanium’s promotion of an environment for bone to grow. Plasma-spray or acid-etched titanium surfaces without substrate porosity, for example, may yield surfaces for initial expulsion resistance (preventing the cage from moving after implantation) and provide surfaces for bone to grow onto, but they yield little long-term ingrowth to provide the best fixation and long-term results.
Industry research has established common pore and strut sizes, however, further challenges must be studied:
Surface morphology of lattice structures – macro, micro topography
Lattice type, shape manipulation for optimal initial attachment, long-term proliferation
Correlation between optimal pore/strut sizes, macro stiffness of structures – preventing stress-shielding, adjacent biological issues
Manipulation of mechanical properties via computational methods (functional lattice grading, topology optimization)
Section view of a simulated vertebral body segment showing the ability to mimic the morphology of bone and its seamless transition from trabecular to cortical features.
Many software tools struggle to build the kinds of structures that will lead to the next generation of orthopedic implants. Furthermore, selective laser melting (SLM) machines are becoming more advanced, manufacturing complex structures with strut sizes smaller than 0.100mm (0.004") and features as small as 0.080mm (0.003").
Next-generation software provides tools to harness SLM capabilities, allowing advanced lattice-feature manipulation. Newly developed capabilities allow design engineers to take triply periodic minimal surface (TPMS) lattices and grade them to any ramped structure.
Rather than stop at linear remapping, any geometry representation can be altered in each axis with any complex parametric equation. Complicated models can also be generated via parameters or topology optimization and used to functionally grade structures.
Top, example structure showing the transition between a solid element and an internal latticed structure. Above, Final TPMS Mixed Lattice, with the location of a sphere controlling the gradual transition zone.
Using the inputs (See Figure 1), the volume lattice can be thickened with the Voronoi lattice input. The amount of thickening can be controlled precisely, given parameterization. Where the Voronoi lattice material exists, the final lattice thickness will be greater. The same principles can be applied when setting up the volume lattice – the cellular point spacing can be ramped via any representation that can be conceived and applied.
Complex lattices can also be transformed from one to another with no definable transition point, potentially limiting single weak shear points. Having the freedom to achieve the strut and pore size that produces biological benefits, and maneuvers the structural elements, allows for complex manipulation of orthotropic properties. This further helps engineers evaluate how bone ingrowth will change the macro stiffness of the construct and how to create lattice elements that provide long-term benefits for biological optimization.
Figure 2: Mixed TPMS structures, Lidinoid (L) to Gyroid (R) with different cell sizes.
Manipulating the mixed elements is not bound to a linear input. Objects can be mixed using complex structures or primitive models, (See Figure 2) where the same two TPMS lattices are mixed using an oblate spheroid. Where the sphere exists, the cells are a Gyroid TPMS structure, and the design moves from the sphere transitions to a Lidinoid cellular structure with no obvious transition point.
These tools transition complex lattice shapes to external solid features, simulating biological mimicry of bony structure (cortical and trabecular elements) and the seamless organic transition between them. This type of control over the internal and external structures, as well as discrete control of the transitioning elements, can help give implant developers the ability to alter structural properties on a macro and micro level. It also helps them understand how structures alter as bone integrates into them and engineer implants with specific ingrowth factors.
Figure 1: 1) A 20mm cube with non-variable, 10mm Gyroid TPMS cells. 2) The same 20mm cube with functionally graded Gyroid TPMS cells modified about 2 axes (X and Y). Note that the periodicity in the X and Y directions varies throughout the length. 3) The same 20mm cube with modified Gyroid TPMS cells, where the X-axis has been mapped with an X² function. 4) The first input is a regularly repeating volumetric lattice. 5) The second input is a stochastically generated Voronoi lattice at strut diameter ‘D’. 6) Selectively graded volume lattice using Voronoi lattice input as ramp feature.
This can be further refined by setting up transition phases from one structural element to another – to define continuous mechanical properties from entirely different structural types.
EcoAir surface prep and rust prevention products are packaged in eco-friendly, bag-on-valve spray cans powered by air instead of flammable propellants. The line includes options for bio-based rust removal, water-based void space protection, and water-based cleaning/degreasing with flash rust protection.
Revamped package design and labeling make it straightforward and easy for users to know how each product is applied and whether it is intended to clean, protect, and/or preserve metals. The portable cans are convenient for maintenance personnel, production employees, or preservation specialists to use for cleanup, rust removal, and rust prevention around the shop, on the production floor, or in remote preservation conditions where electrical-powered application equipment may not be an option.
BioCorr Biobased Rust Preventative – Leaves unnoticeable, dry protective film on metal surfaces
325 Tool & Die Rust Preventative – No need to remove before using mold
337 Void Space Rust Preventative – Can be fogged inside an enclosure; diffuses throughout the space, forms protective molecular layer on metal surfaces
3D printing (3DP) additive manufacturing (AM) technologies are the future of rapid prototyping and small/big production lines for industry. There are several variations of this technology; however, there is one with extraordinary potential yet to be explored – selective laser sintering (SLS).
How SLS works
SLS involves powder sintering with infrared lasers in elevated temperatures, which helps the grains of the powder consolidate before being bound with the laser beam. Most SLS printers have a bed on which a roller spreads a thin layer of powder. This powder is then sintered according to the layers sliced from a 3D model file.
Afterwards, the platform moves down by a small increment and the process repeats until the last layer is formed. Next comes post-processing, which requires removing the model from the unsintered powder suspension and sandblasting. Unlike 3DP technologies such as fused deposition modeling (FDM), SLS can 3D print without any support structures for models with complex geometry due to models being suspended in powder.
The two main types of SLS printers are industry grade and benchtop. Industry grade are expensive while benchtop – such as Sinterit’s Lisa or Lisa PRO – are more affordable. The main differences are print volume, process automatization, and material range. Benchtop printers are ideal for academic research, rapid prototyping, and small serial production.
Materials for SLS 3D printers
The variety of materials used in SLS is broad – from different metal powders used in the automotive industry to polyamides and thermoplastic polyurethane (TPU) for the medical market. All powders can be altered for the specific application to achieve the desired mechanical properties.
SLS is a zero-waste technology: unsintered powder can be recycled for next prints. Its small refresh ratio (amount of fresh powder that must be added to maintain print quality) lets powders be reused with a fraction of new powder. However, some powders oxidize quickly and require a neutral gas atmosphere such as nitrogen to preserve the print quality. This solution is present in Lisa PRO, which has a nitrogen intake.
Photo Adobe Stock | mari1408 
Materials for SLS 3D printers 
