Podcast: How to choose the right grinding system for your foundry

Jeffrey Antonic is managing director of Stratecasts LLC. He has over 42 years of international plant operations, foundry/forge, and machining experience. Throughout his career, Jeffrey has worked for Daimler-Chrysler Corporation, Brunswick Corporation-Mercury Marine, Allis Chalmers Foundry and Motor Castings Foundries. He also authored an article titled, “Robotic Grinding vs. CNC Grinding,” which details how to determine the best automated or semi-automated solution for your foundry. Jeffrey recently spoke with Robert Brooks, editor in chief of American Machinist and Foundry Management & Technology, about grinding systems for cast parts.

Below is an excerpt from the podcast:

F: Would you first start by telling us what Stratecasts is and does?

JA: Yes. I'll be very brief. Many people have remembered the name from its founding father, Ken Kirgin. For many years, we published in many magazines the annual forecast and trends for the metal casting industry, and it’s much different than normal crawlers or public data. We do it by alloy, by process, by platform. By foundrymen for foundrymen. And that's the differentiator. So, we do a lot of international tracking analysis, types of platforms, effects of things like electric vehicles on our platforms, etc. The second part of the company, which we thought we never would revisit again, but by golly, we are. In the day, everyone remembers the two biggest foundry engineering firms in the world that are no longer in existence. One was Lester B Knight in Chicago, and the other was Giffels out of Detroit, each commanding about 200 engineers doing the big plants. And the gentleman that ran that was Ken Kirgin, who then founded Stratecasts.

We're not selling machinery. We're selling a neutral perspective by foundrymen in the area of casting and new technology. Many times, what we're seeing is that the foundries of today are being supplier driven. They're not getting the real options that they need to hear about before making this huge decision to go forth. So, the other part of Stratecasts is in bringing forth new technology like this, solving solutions and then turning them into projects as needed. But our focus today is about the new technologies that are available and how to make the decisions in terms of grinding.

F: Well, you make a couple of good points there. I don't think it's just foundries. I think a lot of small and medium manufacturers have had to outsource their engineering. And that puts them at a little bit of a disadvantage. I don’t think that's the discussion today, but in any case, there does need to be an infusion of expertise in a lot of these businesses. One thing that occurs to me on this particular subject is that grinding technologies generally falls outside the stated scope of metal casting. They understand metallurgy very well. They understand material technology and forming technology very well. But now we're getting into the next stage, which is how to make those cast parts presentable. Do you find that to be true?

JA: Absolutely. It's a completely different paradigm. It has different EPA requirements, safety requirements, etc. And many times, it's taking up Class A plant space which could be used for production and other things.

F: And just to state the obvious, it's also an issue that intersects immediately or head on crashes with the problem that everyone has with labor. This is a very labor-intensive activity, and you listed not only the EPA issues, but also the OSHA issues involved, so there are those factors as well. And I think that's how a lot of metal casters have come to the idea of selecting their grinding capabilities, their grinding technologies. But let's talk about the contrast that you present. You present this contrast between robotic grinding systems and CNC grinding systems. Does that choice more or less hinge on the volume of production that needs to be done?

JA: Volume and topology of the parts and alloy, because it's not all things. Consider, for example, if we're grinding bronze castings or aluminum. It’s completely different than gray and high-chrome steels. So, you have to have a lot of inherent process knowledge, knowledge of abrasives, speeds, feeds, etc. And let me just go back a little bit and set the platform as to how we got into this and why.

We were hired by a large corporation that was totally confused. They were listening to integrators, they were listening to machine makers, everybody, and they didn't know which way to go. So, they tasked us with going literally around the world and visiting everyone that we could find that was in this business, from India to France to Germany, with a common neutral platform. What’s out there? What's the technology? Even China, in what they're doing. So, having that base knowledge, we were able to make decisions on where the best fit was for platforms.

To answer your question, yes. On high-repetitive parts, the CNC solution is excellent. Even now, they have evolved into smaller batch type machines with easy operator programming and AI systems that can shorten the cycle by repetitive learning of the cycle. When you get into more complex castings, for example, D gating and grinding of curved surfaces that are beyond the fixture capability of a three-axis CNC, especially the big castings. The robotic applications on huge transmission parts or compressor parts, wind turbine parts, is really a sweet spot for that. And we can talk about just generally, we find that between 25 to 40% of the total casting cost is in the grinding and the finishing.

F: That's an important point.

JA: Very big. And this is where we served. We go to the OEMs, we go to the buyers, and say, ‘Look. Your foundries can still make their margins, but if we put these systems in, it's a win win for everybody.’ Quality and safety and, of course, the lack of labor. And now everyone fights back and says, ‘Well, we're a small foundry. We're a middle stand foundry. We can't afford a big robot programming operation or this or that.’ And that's not the case anymore. These toolpaths can be 70%, 80% auto programmed both in CNC and in robotics. We're teaching operators on the floor within 15 minutes to program new parts.

F: I don't want to get off track here, but I was struck by one point you made there about going around the world and checking on this. It had been my conclusion that these were technologies that were being embraced by foundries in North America and in Europe, but I didn't realize that there was much expectation of automated grinding systems beyond them. Am I wrong about that?

JA: Yes. It's astounding. In China alone, there are over seven major producers of grinding CNC-type equipment. Granted, only two of them are highly technical. The others are copycat, basically, of older technologies, but they work. So even though labor is lower cost, we're seeing also great installations going into Mexico, the higher volumes there. So, there are players now making these machines from all over the world in terms of CNC and robotics. And the thing to be careful of, we can get into this later, is how you choose the machines and your supplier. What are the key elements so you don't make a mistake? But no, it's a global situation.

About the Podcast
Great Question: A Manufacturing Podcast offers news and information for the people who make, store and move things and those who manage and maintain the facilities where that work gets done. Manufacturers from chemical producers to automakers to machine shops can listen for critical insights into the technologies, economic conditions and best practices that can influence how to best run facilities to reach operational excellence.