Selecting the right volume packing and part orientation tools

A recent survey revealed a number of fascinating developments in the way additive manufacturing companies’ long-term goals are evolving:

• Increasing project turnaround speed emerged as the main goal for most companies, followed closely by reducing operational costs
• More than 50% of companies surveyed were actively looking to develop AM as a production tool rather than purely a prototyping one

However, the answers for how to best achieve these goals proves elusive. There are numerous elements to consider, and customer requirements and expectations are evolving year by year. However, one essential element for increasing speed, reducing costs and developing effective production processes is the need to implement an effective volume packing (also called ‘nesting’) and part orientation strategy.

Laying the foundation for effective nesting and part orientation processes

A well-considered approach to volume packing and part orientation will help you get the best possible results out of your machines, delivering more parts in each print run while maintaining quality standards and minimising material wastage. However, there is no such thing as a one-size-fits-all solution when it comes to nesting and orientation. There are simply too many variables with additive manufacturing projects — all of which must be taken into account.

Before any decisions regarding volume packing and part orientation are made, it should be established what each part in the print run will be used for and what the surface requirements will be. This will affect the part orientation, and in turn, the build nesting, as other models will have to be nested around parts that require the orientation to be locked. In terms of part orientation, its importance will largely depend on the printing method involved. For instance, part orientation has less effect on the final product with SLS printing methods (although it will still affect the overall build time), but will have a huge effect on build quality for SLA and FDM projects.

The value of strategic automation

With a considerable number of factors to consider, the AM sector’s gradual move towards strategic automation through the use of software-based productivity platforms offers a range of opportunities here. Additive manufacturing software suites that incorporate tools for managing nesting and part orientation are becoming increasingly sophisticated, making use of closely-guarded algorithms to optimise volume packing and orientation. Ongoing research is taking place to further develop effective volume packing algorithms, notably at the University of Nottingham.

Two of the most well-regarded platforms for this purpose are Materialise Streamics and Autodesk Netfabb:

Materialise Streamics

Advantages:

• Interacts directly with selected machines using multiple file formats
• Integrated with other tools in the Magics software suite
• Build optimisation and shape sorter functions, allowing builds to be organised around a ‘master’ part’s orientation
• Highly customisable: 6 entities available for determining part alignment and user-defined coordinate systems

Disadvantages:

• Expensive compared to other software packages

Autodesk Netfabb

Advantages:

• Adjustable packing parameters (density, speed etc.)
• Orientation can be arranged relative to the bounding box, or other parts
• Parts can be automatically arranged by outbox or real contours — highly flexible
• Incorporates Monte Carlo Packer as alternative packing tool

Disadvantages:

• Nesting tools not available in standard package.

Making the right investment

Whichever platform you invest in, it must be established beforehand that it will run effectively on your systems. For industrial applications, the desktop version of either program will prove insufficient, as neither product is designed to handle large-scale prototyping and production, and lack some of the specialist tools for nesting and orientation that come with the industrial-focused versions. This will require either powerful desktop workstations or a network server with sufficient capacity to handle the software.

The speed with which your systems can run your chosen software platform is likely to affect your build times. Nesting and orientation tools require time to run, and should be allowed whatever time is necessary to deliver the optimal results. Ensuring your systems are able to fulfil the software’s minimal requirements will reduce this time and enhance your overall efficiency.

If all these factors are considered, investing in the right additive manufacturing software will help you develop a robust nesting/orientation process, with the flexibility to manage a wide range of projects. This, in turn, will help you get the most out of your machines’ capabilities, whether your focus is on prototyping or production.