Additive Manufacturing – A New Tool in the Manufacturing Toolbox Part 6

Advice on Adoption
Blog Written by Hutch Hutchison, Director, Technology & Engineering Matching, FuzeHub
This week, we get down to “brass-like” tacks, as the Additive Manufacturing Industry is fond of characterizing. (As more and more materials are created and modified to adopt to AM, you find descriptions like “ABS-like” and “Polycarbonate-like”, as their properties are designed to emulate the real material, yet chemically and physically adaptable to AM processes.)  We will describe the analysis necessary to determine whether to go the AM route or stay the Subtractive course. Further, we will list manufacturers and approximate costs, review materials, give you a “scorecard” to help decide, and give advice as to how to break into this exciting, explosive field.
Let’s start with a “problem” that GE Aerospace had, with the manufacture of its LEAP jet engine fuel-injection nozzles. The nozzle, shown in the image below, was a complex assembly of 18 parts, each cast, formed, machined, heat treated and inspected over a substantial period of time, at substantial cost, and resulted in solid parts, representing weight, a bane of an aerospace part in terms of fuel efficiency.

 
 
 
 
 
Once the 18 parts were fabricated, they were welded together in another time consuming and costly process. The quality control of the welds had to be impeccable, and then finish machining and heat treatment added to build time and costs. GE, thanks to the acquisition of Morris Technologies in Cincinnati, OH, investigated the possibility of AM, using an EOS Selective Laser Sintering process (See Additive Manufacturing 3). The results were astounding: A 25% reduction in weight, significant reduction in time, and substantial cost savings. (Sorry, GE hasn’t revealed all the details.) A recent (8/6/13) introduction of a unique QA process from Sigma Labs has resulted in another quality improvement by inspecting the melt ”puddle”, dynamically. (This is a “big data” application, and Sigma Labs helped with the data analysis with QA in mind.)  The QA process also reduced the build time by another 25%.
GE is gearing up to produce some 25,000 nozzles annually! Who says AM can’t produce in volume? One of the advantages of AM is that it can be a “lights out” operation, once running, overnight parts runs are commonplace.
I cite this example as a guide to those of you who are in the manufacturing of parts, like the nozzle. Consider the savings potential in terms of time, cost, material, quality, and weight that AM can afford, before making a move to adopt it!
On a smaller scale, a NYS Manufacturer was approached by an inventor, who had thought of a novel bicycle hub assembly that would be advantageous to high-end bicyclers.  The hub:

could only be fabricated by electronic discharge machining (EDM), a time-consuming, costly process, with potentially low-yield and a price tag that would not make it competitive.  The inventor approached the Manufacturer, who had a reputation for using AM for both production tooling and for finished parts, using his EOS Selective Laser Sintering device. The engineers for the manufacturer determined the appropriate geometry to supply added material, so that final machining could bring the part to the desired finish and shape. Additionally, the metallurgists determined that heat treating would be necessary to provide the proper hardness of the “grown” hub cluster.
The result was a capability to Additively manufacture the part, machine it to final finish and specification and heat treat. The manufacturer developed a production process that incorporated AM as one of the tools to make the part, and the inventor came away with a sufficient quantity of hubs that could be profitably yet competitively priced, and has encountered no failures in its production history.
Another analysis that supports AM would be: “Could I manufacture it any other way?”  Consider conformal cooling channels under the surface of a mold, or a cooling channel in the center of a curved turbine blade. How would you manufacture that with subtractive methods? Yes, CNC machines and EDM would provide the net shape of the part, but no drilling process could yield the conformal cooling tubes.
Consider this structure:

The lattice structure of this part, additively manufactured via SLS, contributes the same strength as if the part were made of solid titanium, but with 10-20% of the original weight, if the part were conventionally manufactured. The CAD file would contain the final “skin” of titanium, making it a finished part, but it would be impossible to tell of the structure beneath the skin. The only consideration to be had in AM is how to remove support material that maintains the structure during the build, in this case unfused metal powder. The designer would have to put in access ports to allow the supports to be removed, which would be translated to the .stl file governing the build.
So, by way of a quick summary of motivation to switch to AM: 1. Complex build process; 2. Otherwise un-manufacture-able.
Another motivation to adopt Additive would be tooling. Simple, urethane molds, faithful to the design of the part, can be made from the least costly, plastic-like AM devices, including the oldest: SLA. Other tools, including jigs and fixtures can be quickly made on demand, with the CAD file.  The same manufacturer that has done the bicycle hub, makes his own metal molds, often with conformal cooling, using his SLS machine for double duty. In the medical field, tools from simple holding fixtures to complex models of the human organ that is to undergo surgery, so that the surgeon can “rehearse” the operation are in use today.
Consider this part, a vacuum gripper:

The original part needed to pick up conical parts up to 19 inches in diameter. It literally tripped over the mélange of vacuum hoses needed to obtain vacuum at each pickup point. Digital Mechanics AB engineers designed the gripper shown, to be produced by a Fused Deposition Molding (FDM) process, which had the vacuum lines internal to the gripper arms. Not necessarily un-manufacture-able, but much more convenient with AM.
Other considerations to be undertaken when considering adaptation of AM:

• Low Volume
• Flexibility (I liken this to mass customization. (Think hearing aids – multiples in one run!)
• Greater Efficiency (Not unlike the complexity problem that GE had with the nozzles.)

I have put together a “scorecard” in order to help you determine your amenability to AM. But first a disclaimer: This is MY idea of a scorecard, based on affiliation with AM for 20 years. You may gain more expert advice from a consultant, but if your scores are close, I would get the consultant anyway.
Here’s the scorecard:

If you score the part(s) you want to do Additively, and get less than 50, maybe it is not for you – yet. A score from 50-100, do the analysis, compare current processes and maybe consult about going with AM. Above 150, Additive is definitely in your future!
I promised manufacturers and pricing, so here is a table, primarily of US manufacturers. Objet, an Israeli company that makes Polyjet printers, just merged with US’s Stratasys, so it qualifies for a US company. I include EOS, a German company that is at the forefront of metal AM devices with their SLS Systems:

Please note that this is not an exhaustive list, as more are added every day. Further, these are what I consider manufacturing machines. One can purchase a small (6 inches cubed) 3-D printer for prototype use for around $600.
Currently, universities and NAMII are researching various materials at a breakneck pace. Here is a chart which postulates materials associated with a process:

Now it behooves me to express my opinion about the pros and cons of Additive Manufacturing. Agree, or disagree, here’s my take on the technology:

                          PRO’s                                                                                                  CON’s

 
My primary piece of advice to manufacturers is to GET BEYOND THE HYPE ! Contemporary media have had a field day announcing all the wondrous things that can be manufactured additively. Get past that. Consider AM as you would any tool in your plant, especially considering the cases I have cited in terms of complexity and/or not manufacture-able otherwise. Draw your journeymen machinists and/or engineers into the decision process, they will have ideas.
The most successful adopters of Additive Manufacturing that I am aware of started off with a machine, primarily as a prototype tool. (It is hard to beat AM for quick-turn prototypes to validate a design.) Once the machine was in their shops, their people proposed experiments to use AM for tooling, fixturing, and ultimately production. Once in production, AM was treated like any other tool, and found its place in the work flow, among CNC machines, and heat treatment furnaces. Experimentation is key, once you have AM they seem to come naturally!
It is relatively easy to “get your feet wet” in AM. Service bureaus, all over the State and US, can provide the first exposure, 3-D Printing your ideas, from input as little as a napkin sketch, to the CAD model, even a scan or photo of a device.  Use the service bureaus until you have made the financial case to purchase your AM device. Most service bureaus offer quick, free quotes, and turnaround in a few days for parts.
As you continue your romance with AM, consult with the OEM’s who manufacture the machines, as far as adoption of a process (e.g. SLS.)  Most OEM’s would be happy to work with you in printing your parts, iteratively, so that you can gain comfort with their process and devices. In NY, thanks to the grant that I have been working on, we have a database of resources to provide prototypes of your ideas, just contact us at FuzeHub. We have resources that can take you all the way through your product development, as part of our database. We are also ready to advise you on your path to AM acceptance.
Consider these bullet points, when you are thinking of adopting AM:

• —  Definitely use AM for prototype if it fits
• —  Use Service provider at first
• —  Fuzehub can provide locations, advice
• —  Cost effective for low volumes!
• —  Buy the small printer for concept  or tooling if desirable
• —  If design is otherwise not manufacturable, go for it.
• —  But, start with service bureau
• —  If it is already manufacturable, start with comfortable methods.
• —  Analyze for compatibility with AM  (think GE Cost Savings!)
• —  Redesign for AM?
• —  Expand, pilot run AM with service bureau or machine mfr.
• —  Have a materials expert available!

—  Consider investment in AM if tooling/ fixturing driven
—  Try before you buy!
In conclusion, we have spent 6 weeks exploring Additive Manufacturing. I hope that you come away with a clear view of the field, the processes, the machines, the materials, some of the “gee whiz” things going on, and advice on how to adopt the technology. Here are the highlights:

• —  CAD design,  Computer Scanning, materials technology combine to form a manufacturing revolution.
• —  Parts/tools/fixtures made quickly, cost efficiently, risk-less
• —  Virtually any material, with sufficient viscosity or fusibility, can be used with processes.
• —  Rapid Protoyping/Additive Mfg. technology becoming an outright R&D uprising at universities (materials!).
• —  Scanning, Software, Machine development making AM a viable tool for manufacturing. (Alongside other tools.)
• —  GE first major manufacturer to invest heavily in AM
• —   8/22/12: President Obama announces Additive Manufacturing Institute in OH/WV/PA
• —  Serious medical/biological applications emerging.
• —  Get beyond the hype: It’s another TOOL!

As FUzeHub progresses, look for more posts from me on Additive Manufacturing, at least. I will be keeping an eye on all of the Advanced Manufacturing Technologies, expressed in the Report to the President from the President’s Council on Science and Technology. They include:

• Sensing, measurement and process control
• Materials design, synthesis and processing
• Digital manufacturing technologies
• Sustainable manufacturing
• Nanomanufacturing
• Flexible electronics manufacturing
• Biomanufacturing
• Additive manufacturing
• Industrial robotics
• Advanced forming and joining technologies

If you have requests for other Manufacturing Technologies you would like to hear about, please leave a comment!