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Computer numeric controlled (CNC) machining equip...
CNC Machining: Making Dollars and Sense
Computer numeric controlled machining equipment has been available to engine builders for about a decade. A great deal of effort has been expended by manufacturers and suppliers to promote the benefits of the equipment – with mixed results.
By Doug Kaufman
"For the first time, we saw people who weren’t overwhelmed by the concept of CNC machines,” Matt Meyer said about the recent PRI trade show. “This was the first year that most people really seemed to know what they were looking at and understood that CNC machines are a viable part of the automotive machine shop.”
Meyer, from RMC Engine Rebuilding Equipment in Saginaw, MI, says he was pleased to realize the majority of visitors to his trade show booth are beginning to recognize that CNC machining equipment is not futuristic, out-of-reach technology that offers benefits only to rocket scientists and high-end race shops.
Computer numeric controlled machining equipment has been available to engine builders for about a decade. A great deal of effort has been expended by manufacturers and suppliers to promote the benefits of the equipment with mixed results.
“I believe more and more engine builders are realizing the value of these machines. Each year, our sales volume has increased pretty substantially,” says Ed Kiebler, with Kent, WA’s Rottler Manufacturing. “Still, I think there are plenty of engine builders we haven’t gotten the word to.”
John Cowher, from Centroid Inc., Howard, PA, agrees: “Some of them really understand the value of CNC equipment to their business...but the ones who don’t understand what the gains can be don’t have any idea of the equipment’s value.”
Kiebler believes the perception that CNC is out of reach, while changing, is still somewhat prevalent. “I do believe that perception needs to change. Frankly, it’s very hard for someone who has been used to spending $30,000-$40,000 on a boring or surfacing machine to suddenly step up to $80,000-$120,000 or more. Honestly, the engine builders who already own the machines probably realize the value better than anyone else.”
John Roth, of Haas Automation, Oxnard, CA, says unlike most other machine shop environments, CNC equipment isn’t the norm. “Manual machines are still prevalent in engine building, which is interesting, considering that they are pretty much non-existent in a typical machine shop today. Engine builders who do make the investment in CNC clearly have a competitive advantage.
Although many engine builders may be comfortable with manual machines and may still be wary of computerization, RMC’s Meyer says the landscape seems to be changing. “The more educated people get, the more machines that are out there, the more likely it is that someone knows someone who has one. Whether its a full CNC machine or just some aspect of it, it’s more common than ever.”
And Meyer says the more they ask questions and look carefully at the features and benefits, the more often engine builders are pleasantly surprised by the costs. “A lot of people assume the costs are way out of reach, but with a lot of the turnkey packages out there, the costs can actually be pretty reasonable.”
Expense and payback are obviously important topics to small business owners and engine builders and automotive machine shops are no exception. Especially when traditional business models seem to be obsolete and shop owners hear appealing reports about CNC machining equipment working around the clock, offering non-stop productivity...something they can only dream about with the typical employee. But the question must be asked: do the initial costs of buying the equipment put it out of reach of the typical shop?
“We don’t think it does, says Centroid’s Cowher, “but it all depends on your definition of CNC. We try to make our equipment accessible to the typical shop, whether that’s a 2- or 3-axis machine to a fully enclosed machining center.” In other words, what you reach for should be dictated by what you need.
The key is understanding the payback, explain’s Haas’ Roth. “Obviously, payback on a machine depends on throughput and utilization. When doing a cost justification, it’s important to consider the increased throughput that CNC machining makes possible: increased throughput that equals shorter lead times and room in the shop schedule for more customers.”
Rottler’s Kiebler says he doesn’t believe the technology is out of reach, based simply on the actions of a typical performance engine builder with a typical performance engine. He is very likely going to bore, deck, block and true, lifter bore, install 4 bolt main caps or line bore the block; he may want to measure (probe) the block to determine how close the block is to blueprint specs and he may want to bore the cam bores to accommodate roller cam bearings. That’s a lot of steps!
“We have a number of customers telling us they actually save about two days labor on this type of machining and measuring operations,” says Kiebler. “I know shop labor rates vary widely in this business but even if we say $40.00 per hour (which is extremely low) that’s a savings of $640.00 in labor alone per block! I’m not sure you could gain that type of productivity anywhere else in the shop.”
A shop with outdated equipment that still has a good clientele base, a good reputation and realizes it must revamp its operations to be competitive is an ideal candidate for CNC equipment, explains Meyer.
“When they start looking at replacing head resurfacers, boring machines, a mill with drilling and tapping capabilities anything that is designed for accuracy they start adding up the machines and they realize pretty quickly that they can get to what a CNC machine costs out the door,” Meyer says.
“Not understanding the consistency gains with a CNC is a real drawback,” explains Cowher. “You simply cannot hand port something exactly the same every time. With CNC, you’ll get that consistency in every port, combustion chamber, manifold but if the machinist doesn’t recognize that benefit and its value, they won’t pay attention.”
Roth agrees: “The technology is almost a necessity if for quality reasons alone. A CNC machine will produce more consistent, more accurate parts, be it decking or truing lifter bores, line boring or head porting. The advantage of CNC porting is absolutely massive over manual porting, in terms of time and consistency.”
John Trusty, with Millport Engineering Co., Ravenswood, WV, explains that many people look at CNC equipment for one thing, then realize a wider opportunity exists.
“They’re often getting a CNC machine with the interest of doing a specific task,” Trusty says. Then, after they’re trained on the machine and after seeing the capabilities of the equipment, they realize there’s a much greater potential to make all types of other things. Once the imagination takes over, it’s wide open.”
The term “justifiable expense,” of course, is relative, but whether it’s a one-man shop or a full NASCAR race shop, realizing your current equipment is out of date and you’re doing things the old fashioned way and you’re just not able to do some things at all can change your perception. “When shops recognize that one machine can often let them do all those jobs, plus add accuracy, increased versatility and very important save time, it’s a big step,” says Meyer. “After all, time IS money.”
Experts say CNC machining opens up possibilities that simply are not practical for a non-CNC equipped engine builder, such as serious component lightening or engine block modifications.
“The other obvious benefit is floor space requirements,” says Kiebler. “Floor space doesn’t come cheap in today’s world. The machine literally takes the place of your boring machine, surfacing machine, line honing machine (.0002˝ tolerance on main bores) and line boring machine. You can also do cam boring for installation of roller cam bearings. The probing feature on these machines is probably one of the most productive functions of the machine. In a matter of a couple minutes you can determine the accuracy to blueprint of your lifter bores, cylinder bores, deck surface and deck height along with main bores before and after you machine the block.”
Cowher says repeatability is a key factor. “Doing one-offs is going to be a lot harder to justify than having a dedicated engine or cylinder head program. Machinists need to understand the value of what they can offer and what people will be willing to pay to be able to figure out their ROI. When you’re creating a full-race cylinder head, for example, that is $20,000 vs. a 4.6L Ford cylinder head that may cost a couple hundred bucks, it may help to make the decision of what kind of machine you need to buy.”
Of course, having the ability to do so many advanced operations doesn’t mean a thing if you’re not trained correctly. And with such extensive possibilities, the training must be overwhelming to the average machinist, right?
The training offered by each manufacturer may vary, as to intensity and location. It’s a key question you should ask when you’re investigating the purchase of a machine.
“Really, the training curve depends on the person,” explains Meyer. “Our machine is a fully programmable four-axis CNC machine. Fully programmable means the limitations are in the operator. Basically, if you can hold it in the machine, make tools to run on it and program it, you can get it done.
“That being said, the problem we’ve seen is in customers who don’t have an open mind for learning and no time to spend with it. If you don’t have the time and dedication to put to it, you’re not going to get the benefits from it,” Meyer says.
“How much training do these machines take?” asks Trusty rhetorically. “Some will say using it is a piece of cake, and yes, step-by-step, it’s pretty simple operations. But when you put them all together, it can be pretty robust. Training is definitely necessary.”
Cowher answers that same question: “How long does training is needed? As much as the user requires to get the ROI a quickly as possible.” He agrees with Meyer that the training curve will vary with each user.
“We believe training is one of the important issues to a shop purchasing this kind of equipment,” says Kiebler. Our factory-trained techs will come in and spend the necessary time to get you familiar and operating the machine. Depending on the amount of options you purchase with machine this can be from 3 to 5 days initial training.”
Says Haas’ Roth, Cylinder head porting is a complex job. It’s a marriage of scanning, CAM and machining that shouldn’t be taken lightly. But with proper training, it’s not beyond the capability of most people. Spend time with your machine vendor, explain clearly your objectives, and they can help connect you with the right training and third-party suppliers. For head porting, some shops even opt to have a common configuration turnkeyed by one of several CNC porting specialists. While this shortens the learning curve, it also limits what the shop can accomplish on its own, to some extent.”
Helping to ease the conversion to CNC for some engine builders is that the majority of automotive CNC machine centers (which are multi-purpose CNC machines made specifically for engine work) offer nearly turnkey programming. There’s no need to spend evenings and weekends in a classroom trying to learn G-code, the prevalent programming language, in order to carry out traditional engine block machining.
G-code is a term that has been around the industry for many years and is supposed to be standardized in the industry, but its not, explains Millport’s Trusty. “Most of your CAD/CAM systems output G-code, so it’s the universal language between machines. But some manufacturers have leading zeros and some do not. For instance some may specify G1 and some say G01, so there’s a differentiation between the G-codes that are available for various manufacturers.”
Every manufacturer does it a bit differently but the goal is the same: create an easy-to-use interface between the user and G-code output. Kiebler explains how Rottler does it: “With our exclusive programming anyone can operate this machine in less than a day with absolutely NO CNC training or Gcode programming. Not only do we offer ease of use but we also offer tremendous versatility. Our CNC machining centers don’t care what type of block you’re machining. It can be V8, V6 or in-line or any make of block. Unlike G code machines that need programming for every style and make of block our machine can be up and running in less than 30 minutes of programming time.
Manufacturers of this equipment have done the homework for you by creating easy conversational programs that insert the necessary information for you to machine any engine you’re working on. Experts say that learning how to do block work can be done in as little as an hour by even the most inexperienced shop hands. Therefore, the urgency for skilled machinists, though still a need, may be greatly reduced.
Software Or Hardware?
With the emphasis on ease of use, is it the software or the hardware that’s most important? “We believe it’s both,” says Kiebler. “First you have to offer the engine builder or shop that doesn’t have CNC training or G code programming knowledge, the same productivity edge that shops that can afford a full-time programmer on staff. Secondly, the fixturing is a critical part of the success of our machine. There are many CNC machine manufacturers but only a few who understand and build fixturing to accommodate engine blocks. To research and build this type of fixturing is time consuming and extremely expensive.”
Meyer echoes that sentiment. “Lots of machines are out there on the industrial side, but is the fixturing right? Is the capacity of the machine correct? Additionally, the programming is critical. We’ve done a lot of work writing programs for doing specialized things in this industry. Finally, the tooling is vital. With the different type of materials found in engines and cylinder heads, as well as other components, you need to make sure your supplier has the ability to meet your needs with regard to cutting heads and special tooling.”
Roth picks up that train of thought: “Hardware or software? It’s a whole package. A great CNC machine will have a simple, user-friendly interface and well-engineered electronics driving high-quality engineered mechanics. They are all important.”
He continues, “Just as important is service. Service and spare parts support are critical. Engine builders need to seek vendors that can support their needs quickly and efficiently. “
Centroid’s Cowher says this about seeking a supplier: “if you invest the time up front, researching the products that can meet your needs now as well as where you think they may be going, the easier it will be in the long run.
“My biggest goal, is to get people to overcome their fear of CNC. They’ll get more throughput and be able to take on bigger projects. They might be surprised at how quickly they make their return on investment if they investigate it.
But Cowher concludes. “You’re not going to do this without wanting it.”
For More Information
The experts quoted in this story talked about the importance of building a positive supplier relationship in your quest for CNC machining information. Additional contacts can be accessed at our exclusive Engine Builders Buyers Guide.