ADDITIVE MANUFACTURING is the magazine devoted to industrial applications of 3D printing and digital layering technology. We cover the promise and the challenges of this technology for making functional tooling and end-use production parts.
Issue link: https://am.epubxp.com/i/667993
AM / Caterpillar Lays the Groundwork additivemanufacturing.media 29 diferent casting designs, and experiment with all of them? This is a level of freedom not typical of foundry work, and one that design engineers today can beneft from coming to understand. He is enthusiastic about getting to be part of this learning pro- cess for the company. A frm like Caterpillar does not face FAA or FDA restrictions, he points out—meaning it can move forward on new products developed through AM more quickly than compa- nies in other industries. Then again, some AM benefts important to other industries simply do not apply. Weight reduction is an example. Equipment such as earthmovers beneft from being massive, so weight sav- ings generally are not worth pursuing. Caterpillar, distinct from other manufacturers, will fnd its own way forward with AM. Getting to Production The company's Joe Taylor has perhaps the clearest view on how far AM technology still has to go in order to realize its promise as a production process. The additive manufacturing engineer oversees the operation of the Additive Manufacturing Factory, just as he has overseen more traditional manufacturing resources and departments for much of his nearly 20 years with Caterpillar prior to this role. In prototyping, he says, 3D printing saves cost for the com- pany all the time. This has become routine. In one recent case involving an assembly of 25 pieces, 3D printing all of the com- ponents revealed interferences afecting fve of those parts that had not been not seen in the CAD models. In the past, problems such as these might not have been discovered until the parts went to production. Similarly, prototyping of ducts and valves provides an inexpensive way to test and refne fuid fow before designs are released. However, when it comes to production, there are obstacles to cost saving. Material price is the frst of these that he cites. "The cost of powder material has to come down," he says. This is truer for Caterpillar than for other AM users, because aerospace and medical OEMs employ metals for which high cost is the norm. But Caterpillar's products are made from iron, aluminum and steel. Listening to Taylor, I expected him to add machine envelope size to the list of obstacles, because I equate Caterpillar with big vehicles. But that's not a concern as yet—plenty of production parts would ft in the envelopes of today's metal additive ma- chines. When it comes to the machines today, he says the limiting specifcation that is more concerning is speed. The fuel flter base took 80 hours to build. Such a cycle time is acceptable for service parts (maybe), but not acceptable for production. Yet lower cost and faster speed are both diferences of degree. He says there are also ways that the basic functionality of additive machines will have to change. The metal machines in particular require too much attention, he says. Too much human involve- ment is required in change-over between jobs. Even if additive would be used only to make aftermarket parts for Caterpillar, which by itself would be valuable, this use alone would require 24/7 operation of the machines (and many more machines would be needed). So far, the machines have not been engineered with this type of operation in mind, he says. He envisions something like hoppers for continuously feeding new material, along with features that speed and simplify job transition. These changes are probably coming. Maybe they will come in 10 years, or maybe they will be here in as few as three. When they do come, where will Caterpillar be? Conklin says that's the question the company is aiming to answer with the Additive Manufacturing Factory, and with the training eforts and application successes radiating out from this. When AM capability is ready for production use, one possibilty is to miss out on its benefts. But an alternative possibility for that day is to have the company already stafed by people who have been thinking about additive for a long time, and who are ready to realize its potential. This hose clamp was grown in FDM. It also matches a current design. It was printed so that its performance could be compared to parts currently in use.