There is a problem surrounding the additive manufacturing (AM) and 3D printing (3DP) industry that is rarely discussed, but is not going away any time soon.
I would be the last person to dispute the amazing capabilities of AM and 3DP hardware systems used for industrial applications. The ability to build complex parts in one piece and the advantages this brings of increased strength, lighter weight, reduced material consumption and assembly component consolidation for an increasing range of applications are all well documented.
The focus tends to be on the hardware, but this does not convey the full picture of what is required to get that part ‘off the machine’.
AM hardware systems are part of an extensive ecosystem of technologies including pre- and post-process. These days a greater emphasis is being placed on the pre-processing discipline of design for AM (DfAM), file preparation and file format. In the previous issue of Disruptive Insight, Kruno Knezic addressed some of these issues in his article Creativity is the key to design for additive manufacturing.
But there is less discussion around in-process and post-processing, specifically the ancillary hardware that is critical to an additive process and the time it adds to the actual build time, the space it consumes and, most notably, the cost it adds to the purchase price.
This is not a new problem born of the many new processes and machines now available. Historically, stereolithography (SLA) systems have always required curing ovens, often larger than the AM machine itself. Similarly, the laser sintering machines of the 1990s needed powder handling/removal systems and recycling hoppers and sieves, not to mention the personal protective equipment (PPE) required for machine operators.
The post-processing options for plastic sintered parts back then also invariably required infiltration operations as well as finishing processes, particularly if aesthetics were important alongside the strength advantages that laser sintering offered. The fused deposition modeling (FDM) process also required finishing processes to eliminate the very obvious stepping effect of the process during its early years—baths of chemicals, and later water baths for water-soluble supports, were common requirements, not to mention the endless sanding.
Today, additive processes and the materials used to build parts are considerably more advanced than they were in the 1990s. The materials palette is much broader and resolution, accuracy and repeatability are consistently meeting the industrial requirements for critical prototyping, tooling and some production applications. What is still frequently overlooked, however, is that these achievements often require secondary processes that barely get a mention, certainly not in the marketing materials or the sales pitches. As stated above, these secondary processes demand considerable investment that can double the price of the actual 3D printer as well as increase both time and floor space required.
It is noticeable that the term ‘post-processing’ is often used interchangeably with ‘finishing’, but this is somewhat misleading. With AM processes, there are a series of essential post-processing steps prior to the 3D printed part finishing stages.
Today, most resin polymer additive processes still require oven curing. Laser sintering and laser melting additive processes still require powder handling equipment. On an industrial scale this can occupy two or even three times the footprint of the additive hardware itself. For metal parts, removal from the build plate is a necessary part of post-processing, and that’s before even starting on the support structures. Moreover, the PPE equipment for metal powder processes is more essential than ever.
But even consider the new, more accessible plastic powder bed hardware from Formlabs. Launched this month, the Fuse 1 system is an industrial desktop machine that offers, proportionally, the power and material advantages of a powder bed fusion system in a compact, more affordable format than current alternatives.
This is a welcome addition to the market: accessibility is one of the keys that will continue to drive uptake and adoption. The eye-catching headline price of this system is 9,999 USD. But if you look at the website, it ‘starts at’ those prices. That’s because, when you look at the technical specifications, the price is for the actual printer, but a ‘complete SLS solution’ requires considerable ancillary equipment. Indeed, the complete solution includes the printer, a post-processing station and intuitive software for setting up and managing prints, costing twice the starting price at 19,999 USD.
It was actually a conversation about the Fuse 1, in this regard, that triggered this article. And it made me think on how often the excitement of a new launch overlooks the ancillaries issue.
HP did something similar when they launched the Multi Jet Fusion (MJF) AM system months ahead of the HP Jet Fusion Processing Station required to provide the complete processing solution. The ancillary equipment required for MJF parts post-build easily doubles the footprint of the 3D printer, not that small to begin with, and adds considerably to the cost.
Looking at some of the other new(er) AM system offerings, it is obvious that vendors are aware of the issues with ancillaries, and while they are not talking about them, they are attempting to overcome some of them with their tech development. That said, there is always the need to make trade-offs depending on application requirements, process requirements and budget.
Carbon’s continuous liquid interface production (CLIP) technology, launched originally on the M1 3D printer, is a resin polymer process that produces parts which need to be cleaned and cured. The significantly fast speed of the printing process itself is offset somewhat by these post-processing steps. However, Carbon’s business model goes some way to mitigate this. First, the company’s business model is subscription-based, meaning that the costs include all the ancillary and post-processing equipment as well as the software updates. Furthermore, the recently launched SpeedCell solution, built around the latest M2 printer and incorporating a Smart Part washer, affords increased automation for the cleaning phase. It’s all moving in the right direction.
Desktop Metal is another company addressing head on some of the ancillary issues. DM launched its new powder metal 3D printers with full visibility of the ancillary furnace that is required post-build. In terms of part removal and support removal, the company has addressed the need to reduce the time and effort required for these post-processing steps. Another trade off.
And then there is Rize. Post-processing, or rather the lack of it, is one of this company’s unique selling points. I gave them a bit of a hard time a couple of months ago for using a tagline ‘zero post-processing’. At the time, it was about sensationalized marketing, which I posted was actually making potential users more cynical than they might otherwise be.
The point here is not about promoting any one technology over another. There is very little point in doing that because process selection is and should be application driven. The point is to raise awareness of the ancillaries required to make 3D printers work at any level. It’s the insurance equivalent of the ‘small print’. So, ask the questions and, if possible, talk to experienced users. That’s always where you’ll find unequivocal truth.