7 Questions You Should Ask Before Buying an Additive Manufacturing Machine
If you understand the benefits of Additive Manufacturing and where it fits in your operation, and you are comparing specs and features of competing suppliers, SLM Solutions' Winthrop Sheldon, VP Sales & Marketing Americas, details the 7 questions every manufacturer should ask to help make the right decisions for the long term.
Additive Manufacturing of metal parts (Metal 3D Printing) is a game changer. The technology is seeing explosive growth and acceptance across industries. Business leaders are scrambling to implement and leverage this revolution for competitive advantage. Staying current with this wave of change is a strategic imperative for US manufacturers. The advantages over traditional manufacturing methods must not be ignored. The following questions highlight critical factors you must consider when investing in additive manufacturing technology.
What is the Difference Between Processes?
Making sense of the additive manufacturing "alphabet soup" (and exposing our industry's dirty little secret): AM, 3DP, DMLS, SLM, DMLM, SLS...OMG?
The most common approach to ramp up an additive manufacturing operation quickly is to use materials and parameters supplied by your equipment supplier.
The Additive Manufacturing (AM) world loves acronyms. We won't even try to tackle them all in this brief overview. Instead we'll focus on the most common acronyms related to additive metal processes.
The vast majority of metal printers in use today are based on Powder Bed Fusion Technology. A layer of fine metal powder is spread across a machine bed. The selected regions of the powder layer are then fused to the layer beneath them. The process repeats layer by layer until the entire part is built within the powder bed. Unmelted powder is removed to reveal the finished parts on the build plate. The melting is typically done with a high-power laser.
With that background, here is some industry insider insight. Common trademarked acronyms you will come across include Direct Metal Laser Sintering (DMLS), Selective Laser Melting (SLM), Direct Metal Laser Melting (DMLM), and Laser Cusing. Here's the secret: on today's systems they all refer to the same process. Competing equipment suppliers use the same lasers and the same basic melting process, the only difference is the marketing behind the name.
Wait! -- What??
Wait a minute you may be asking yourself. If the industry competitors use the same lasers and same technology, how do I compare them? What do I look for? What questions should I ask? Now, things get interesting. In fact, there are major differences in how machines are designed and operated. Differences that can accelerate (or hinder) your efforts to gain an edge on your competition. The questions raised here provide a good starting point.
What are My Safety Concerns?
Safety concerns fall into two main categories -- powder handling during operation and maintenance operations. First of all, the powders used in this process are very fine and can contain particles as small as six microns. These are hazardous to breathe so operators must use proper safety gear, or personal protection equipment (PPE) whenever they are exposed to metal powders. PPE is a start, but it can be improved greatly through system design features that minimize exposure to metal powder. Review the recommended sequences for loading and recovering powder and see how many points of concern exist.
Manufacturers should look for a design approach that keeps operators and facilities as safe as possible.
Another important area of safety concern is maintenance of the filtration system. The AM process generates particles and smoke that are filtered to keep the process running smoothly. Periodically, the filters must be changed. Understand fully the steps of this process for the equipment you are considering. Some designs will expose your operators to dangerous particles in the filtration system. Other designs allow safe handling and passivation (neutralization) of harmful content in a sealed environment.
If you are considering use of reactive materials such as aluminum or titanium, powder handling concerns are amplified by a potential danger of fire or explosion. This is a real concern that many manufacturers could overlook -- don't make this critical oversight. Why take chances? Look for a design approach that keeps your operators and facilities as safe as possible.
Does One Size Really Fit All?
Build Envelope: The industry standard machine size for laser-based powder bed fusion machines has historically been a 250mm x 250mm platform with a build height of 250-300mm. This size has stuck around for most suppliers -- but not all. Read the specs and understand the difference that a "slightly" larger envelope can get you.
System Configuration: You can have any configuration you want...as long as it's "the standard configuration." That may not be the answer you are looking for -- but that may be the only thing available.
In an effort to keep things simple, many suppliers have a "one size fits all" approach. That may meet your needs today but be sure to think about this in both the short and long term. Some factors you should consider:
- 1. How frequently will I be changing materials? Is this easy or difficult?
- 2. Are there times when I would like to run small sample tests with potentially expensive materials? Is there a way to limit the material required without going to a smaller overall platform?
- 3. Do I have options for the material used in the recoater blade? (This is an area to explore if fine details and high throughput are important to you.)
- 4. Will I be building large parts that use the entire build envelope? Is there a way to add more powder if supplies run low during a build?
How Can I Get There Faster?
There are many factors to consider around the concept of getting "faster" results from additive metal processes. The time it takes to build a single part is probably the most typical reference point for comparing machines. This is a logical and useful number, but other factors will also have an impact on overall system throughput.
As you move from single part runs to low volume production or larger batches you should think through the following points and scenarios:
- How is powder coated on the build tray? Depending on system design, powder can be spread in both directions or only in one direction. Feeding powder in both directions can save hours of production time. A single build can contain 10,000 layers and "wasted" seconds on each layer add up quickly.
- What options are offered for laser configuration? Lasers are the heart of the system, so if you have more lasers, you can produce more parts -- faster.
- How is material fed to the build chamber? Is the supply continuous or fed from an initial batch of material? Batch fed systems can require the machine to be interrupted to refill supplies during a run, which slows down the process.
- All mechanical systems are going to have operating issues from time to time. Can the system you are looking at recover from minor errors without operator intervention?
Who Owns My Operating Parameters?
Proper operating parameters are the key to building successful parts. Many factors, including but not limited to laser power, scan speed, stripe width and focus settings are developed for each material and each machine. These parameters ensure acceptable quality over a range of part geometries. This development is not a trivial process -- and rarely an exercise for "beginners."
As users move up the learning curve, however, some tweaks to baseline parameters are useful (or needed) to optimize build results. A short list of factors you may wish to optimize for include:
- Build speed
- Surface finish
- Porosity
- Specific metallurgical properties
To modify parameters, you first need to understand what the baseline parameters are. Second, you will need a set of tools to make the trial and error process as easy as possible. This may sound straightforward, but you will be surprised to find that it is not always the case. This aspect of system design is where suppliers vary widely on business policies and the tools provided.
In some cases, parameter sets must be purchased for each individual material. These parameters may be locked to prevent any editing by the user. Parameters may even carry annual licensing fees.
The SLM®500 is built to ensure operator safety and lower overall operational costs.
Other suppliers offer an open architecture for parameters, along with robust tools to help your development efforts. Make sure to understand the policy and feature sets around these parameters fully before committing to any supplier.
Is this new technology an area where you can gain competitive advantage in your market? If so, parameter development and introduction of exciting new materials may be critical to your success. Like any piece of production equipment, the biggest gains will go to the user who invests the time and energy to understand their equipment and how to optimize performance for a competitive edge.
What if I Want to Try New Materials?
As a new user, the most common approach to ramp up quickly is to use materials and parameters supplied by your equipment supplier. This removes variables and speeds up the learning curve dramatically. As you gain experience you may want to explore new options.
Material companies are making huge investments to develop new material variants specifically for the additive market. As you look to the future, it may make sense to know that you have the flexibility to seek new avenues. This issue is rooted more in business policy than technology. Be sure to discuss this issue with potential suppliers. Will they support your efforts by openly sharing experiences? Or will their business practices slow your efforts?
Thanks to their high strength and relatively low density, as well as excellent corrosion resistance, titanium components are found across a broad spectrum of applications.
This issue is closely tied to operating parameters. If you are going to explore new materials, you will almost certainly be developing and enhancing operating parameters. There are advantages in a single source of supply for all aspects of operations (machine, materials and software parameters). However, in a manufacturing environment a "me too" strategy rarely creates a sustainable competitive advantage.
Why take chances? Look for a design approach the keeps your operators and facilities as safe as possible.
What are the "Hidden" Operating Costs?
Additive metal machines have operating costs. These vary as a result of system design as well as business policies. The most important factors are typically:
- 1. Raw Materials: As previously stated, it may be important to have choices for where you purchase materials. This will impact quality, differentiation in the market and, of course, cost.
- 2. Inert Gas: The additive build process requires an inert, oxygen free environment. This environment is maintained by a recirculated flow of argon or nitrogen. The amount of gas required is a significant consideration. Usage can vary by as much as 10x between suppliers -- amounting to tens (or hundreds) of thousands of dollars annually.
- 3. Annual License Fees: Knowing the fee, if any, for use of operating parameters on each material. Other cost items such as electrical power used will be fairly constant between suppliers (after all, they all use the same lasers!).
Conclusion
Hopefully, the points raised here help you better understand some of the important choices you will have to make. Although most suppliers use similar core technology, system design and business policies vary widely. The decisions you make will impact your operation for years to come as the additive metal field will continue to expand and change.
Want more information? Click below.
Rate this article
View our terms of use and privacy policy ::m::