Introducing Foundry | Digital Alloys

Introducing Foundry, Digital Alloys’ Software Platform

July 7th, 2020

Digital Alloys is developing a powerful software platform for implementing Joule Printing™ in production applications and delivering high-quality and efficient operation of printers at factory-scale. We call this platform Foundry. This post provides an overview of the applications which compose Foundry and a glimpse into our future roadmap. We will provide details of each application in future blog posts.

We will describe Foundry by walking through the workflow for producing parts using Joule Printing™. All metal additive manufacturing processes follow the same basic steps, summarized in the figure below. (Refer to our blog on Metal AM Workflow). Core elements of Digital Alloys software power these steps. Data for integration with MES / ERP systems is also provided.

Figure 1 - Joule Printing™ workflow and Digital Alloys software modules

While Joule Printing™ is highly novel, we use as much off-the-shelf software as possible. We develop custom solutions only where existing ones cannot provide all the needed core functionality, or where we see opportunities to improve the ease and efficacy of Joule Printing™.

Design

An additive manufacturing process begins with either selecting an appropriate part and modifying its design for 3D printing, or designing a new part from scratch. Standard off-the-shelf computer-aided design (CAD) software is used for designing parts for Joule Printing.

A part design must conform with the design rules for the 3D printing process (see our blog on this topic). The most important rules for Joule Printing™ are:

today the smallest printed feature is 3-5mm (smaller features can be machined into the part after printing); and
the steepest overhanging feature that can be printed without support structures is 45 degrees.

Essential steps in the design are selecting parts that fit the AM process, identifying features that need to be added in the post-machining step, and identifying where supports will be needed.

An example part is shown below – a conformally cooled H13 steel tool for an automobile manufacturer. For H13 steel tooling, Joule Printing™ offers lower cost and faster turn-around than conventional machining. The part includes a conformal cooling channel that could not be manufactured conventionally. Minimal modifications were needed for this part. The customer selected a pre-existing part design (Joule Printing™ will be less expensive than conventional manufacturing), then added conformal cooling channels. The designer chose a diamond shape with tops that conform to the 45-degree overhang limit so that no supports are needed.

Figure 2 - H13 tool insert for an automotive manufacturer. The part incorporates conformal cooling channels.

Figure 3 - Diamond shape conformal cooling channel

Additional steps performed in CAD during the design phase are choosing a print orientation, adding support structures (if needed), and near-net-shape expansion. The print orientation is chosen to minimize overhangs and the need for supports – the best orientation for our example part is obvious. There is no need for support structures.

Joule Printing™, like most metal AM processes, is a near-net shape process. Printed parts have a surface roughness similar to a sand casting. Where smooth faces are required, extra material is added in a “near-net-shape expansion” – adding material that will be removed by finish machining during post-processing. For this part, 0.5mm of extra material was added on all sides.

In the future, Digital Alloys will add automated support generation and near-net-shape expansion to the Foundry Build Planner, the application dedicated to pre-processing.

Pre-Processing

Once the part design is complete, the CAD file is imported into Foundry’s Build Planner for pre-processing. Pre-processing converts a CAD file into instructions the printer uses to build each layer of the part. These instructions are created by a “slicer”, which automatically slices the design file into layers and generates a toolpath and process control parameters for the printing process. These instructions are described in g-code that tells the Joule Printer how to create the part. Digital Alloys uses a customized g-code protocol that will feel familiar to operators of other g-code-based 3D printers and CNC equipment. The Build Planner also provides the capability to simulate the part build.

Figure 4 - The Foundry Build Planner

For even finer build control, we have developed an integrated development environment (IDE) for g-code. The G-Code IDE is a tool that allows power-users and researchers to make modifications to the toolpath and process-control parameters generated by the Build Planner. It includes powerful features such as integrated g-code protocol documentation and validation. It is not typically needed for normal production operations.

We developed our own build planning solution because we could not find an off-the-shelf product that provided the control needed for optimal Joule Printing™. The Foundry Build Planner has unique, patented features which allow easy, interactive adjustment of the toolpath at every voxel, line, and layer of the part. These features also provide a platform for the future addition of algorithms that automatically optimize the Joule Printing g-code.

Printing

Printing, the next step in the workflow, is powered by the Foundry Printer Console which operates printers and monitors the printing process. This includes distributing the g-code to the correct printer(s), setting up the printer(s), controlling the print, and capturing data for QA & Analysis and for integration with an MES/ERP system. The Printer Console includes:

Console UI dedicated for controlling printer operation,
Real-Time Embedded Software that runs the Joule Printer, and
Operations Manager for capturing data about a printer fleet:
- Printer configuration
- Print metadata
- Consumable usage and print-time statistics

The Console UI provides a user interface for interactively controlling and monitoring the printer. Our printers also include a web camera for recording and remote viewing.

The Real-Time Embedded Software is a hands-free firmware system that tightly controls key process parameters for every voxel in the part. This system includes control algorithms, device drivers, monitors, and an interface with our Console HMI.

Print Operations Management

The Foundry Operations Manager logs important metadata about the activity of a Joule Printer fleet – including configuration details as well as consumable usage, print time, and other statistics that are used to track production costs, measure utilization, and manage consumables inventory. These data are available for incorporation into an MES/ERP system.

The system captures and catalogues all process data, metadata, and print video for every print. The Operations Manager interface (Figure 5), is easy to navigate and search. It uses hyperlinks to connect to the background data and video for every print.

Figure 5 – The Foundry Operations Manager

QA & Analysis

The 4th component of the additive manufacturing workflow is QA & Analysis. The Foundry Data Analyzer is Digital Alloys’ rich platform and toolset for QA. Data Analyzer (Figure 6) allows viewing and analyzing data from the many sources captured in Foundry. It provides a simple GUI for selecting, filtering, and plotting data streams – eliminating the need to download data files to an external software package.

Figure 6 - The Foundry Data Analyzer

This application also enables the synchronization of print process parameters and video to create a print replay, as shown in Figure 7.

Figure 7 - Print playback, showing process data, toolpath, and print video

Furthermore, Data Analyzer hosts a development environment that allows researchers and QA analysts to rapidly create python scripts for more advanced data analysis leveraging the python data science technology stack. Figure 8 shows an example analysis. For this analysis, an operator created a plot showing process power for every location in 13 layers of a titanium part. If there were peaks and valleys in process power that exceed threshold values, that could indicate variations in material properties or defects. Correlations between recorded process values, material properties, and defects provide a rich capability for non-destructive quality assurance of printed parts. Data Analyzer provides a data backbone that can be used to power a machine learning approach to automating the QA process.

Figure 8 - Plots of process power for 13 3D printed layers for a titanium part. Peaks and valleys in process power would indicate potential defects in the part.

Post-Processing

The final product of the Joule Printing™ process is a high-density, low-cost near-net-shape part whose properties are assured by the QA toolset. The remaining steps are few compared to many other metal 3D printing processes. The post-processing steps are:

Smoothing of surfaces where the roughness of the printed part does not meet application requirements,
Addition of fine features that are too small for Joule Printing, and
Removal of support structures.

These steps are accomplished in a single finish machining operation. The part emerges from the printer welded to a base plate. Typically, the base plate is used to fixture the printed part in a CNC machine and provide reference marks for finish machining. After machining, the finished part is then cut from the plate.

For the finish machining steps, we use standard CAD/CAM tools to determine g-code for the CNC machining center. Notably, heat treatment is not usually required for most applications.

Conclusion

Digital Alloys’ Foundry software suite powers the full Joule Printing™ workflow. The platform in place provides the foundation for future innovation – automating key steps in the design, analysis and QA.

In our next blog post, we will provide a more detailed description of one of the software applications. Let us know what you’d like to hear about next by commenting in our social media threads or email us at [email protected].

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Please check out other posts in our blog series:

Digital Alloys’ Guide to Metal Additive Manufacturing

Learn about the technology behind our process:

Joule Printing - The Fastest Way to Make the Hardest Parts

Duncan McCallum
CEO

Digital Alloys is committed to providing the technology and expertise manufacturers need to use metal additive manufacturing in production — enabling them to save time, shrink costs, and produce valuable new product.