Today's Machining Centers Offer More Bang for the Buck
By Larry Carley
More bang for the buck. That's what many machine shop owners say they're looking for when considering a major equipment purchase.
Because today's machine shops are fewer in number and often smaller, it's important for them to have as much capability as possible in every piece of equipment to maximize the return on investment, utilization of floor space and manpower. Consequently, more and more shop owners are buying "dual purpose" machines such as combination boring/milling machines or valve guide and seat machines that can also resurface cylinder heads. They are also buying more equipment with computer numerical control (CNC) capability that allows them to do things they couldn't do before such as automate repetitive tasks.
Dedicated machines for performing individual operations such as cylinder boring, cylinder honing, align boring, resurfacing heads and blocks, machining valve guides and seats, balancing crankshafts and so on, still have their place and are usually required in high volume shops where through-put demands multiple work stations and numerous employees. But in smaller shops where floor space and manpower are limited, a dual-purpose machine or multi-purpose CNC machining center can often provide a practical solution for shops who want to offer a full range of services at competitive prices.
"Why buy two, three or four dedicated machines when you can buy one machine that can do all of the same functions?" said one equipment supplier. By changing the tooling, the same machine can be quickly converted from boring to milling, or from cutting valve guides or seats to resurfacing a cylinder head.
Besides saving the cost of buying or leasing separate machines for each type of job that might be performed on a block or head, using the same machine for multiple tasks also saves time and labor. Once a block or head has been mounted on the machine, it stays there until all the machine work is done. It doesn't have to be moved from one work station to another and remounted for each separate machining operation. Leaving the head or block fixtured in one place also improves machining accuracy and reduces the risk of human error (assuming the part is correctly mounted and located in the first place).
As flexible as multi-purpose machining centers are, they do have one major drawback: they can only do one job at a time. They can't do two different jobs at the same time. Consequently, you can't start another job until the first job has been completed. In a high volume shop, that could create a bottleneck. But in a smaller shop, it might not be a concern at all.
In other words, if you buy a dual- function machine that can be configured to either bore cylinders or mill the block deck, you can bore or you can resurface. But you can't do both at the same time or work on two different blocks at the same time - unless you have two dual-purpose machines or a separate dedicated boring or resurfacing machine.
If you only have one machine and rely on it for both boring and milling, and the machine breaks down, then what? As one supplier of dedicated equipment said, "That's another drawback of multi-purpose machines. If you put all of your eggs into one basket and something happens to that basket, you're dead in the water until you can get that machine up and running again."
CNC-controlled equipment of various types have been introduced by a number of equipment suppliers. A few companies still sell only manually-operated equipment, but the trend certainly seems to be towards greater computerization and automation.
The main advantage of CNC control is that once the proper data has been entered, the equipment can essentially perform the required task independent of further operator input or control. This ability can be used to streamline repetitive tasks, to make complex tasks easier, and to automate processes so the operator doesn't have to babysit the equipment while the work is being done. This can free up the operator to do other tasks while the equipment is running, and it can eliminate many mistakes that are often blamed on "operator error."
When CNC controls are programmed accurately (meaning the correct numbers are entered and the work piece is correctly fixtured and located), there's not much that can go wrong with the machining process. Tool bits can still break, of course, but the CNC process is very precise and offers a degree of repeatability that's hard to match with manually-operated equipment. The result is more control over the quality of the finished process, fewer mistakes and fewer comebacks.
So what happens if the operator enters the wrong information or doesn't mount the work piece correctly? Much of today's CNC equipment has built-in safeguards in the software that is capable of detecting input errors, location and tooling errors and will stop the machine and/or ask for corrections before proceeding.
Some old timers in the business say they're intimidated by CNC controls because they don't really understand how it works or think CNC is too complicated to learn. Fortunately, today's CNC controls are fairly easy to learn and use because little or no programming knowledge is needed to run the equipment. Most CNC-controlled equipment uses "conversational programming" that allows an operator to simply enter data points or numbers instead of having to write actual computer code.
"If you can work at a fast food restaurant, you can run a CNC machine today," said one equipment supplier. "The machines are not difficult to learn, and are very user-friendly. But you do have to think three-dimensionally when entering information and positioning the tooling."
The only drawback of CNC is that it adds cost to the purchase price of the equipment. Adding CNC capability to a machine can add thousands of dollars to its price. Most fully-tooled CNC multi-purpose machining centers cost upwards of $75,000 or more, but there are some basic machines that cost as little as $20,000. Some of the big high end machines can cost up to several hundred thousand dollars or more depending on the size of the machine, its capabilities and the tooling and fixturing that are included.
For a small shop, spending big bucks on a CNC multi-purpose machining center could be a financial stretch that would require a careful review of the books and a serious commitment to growing the business. Even so, many small shops are spending up to $100,000 or more on CNC multi-purpose machines to upgrade their equipment and expand their capabilities.
When done wisely, such an investment can pay back excellent dividends. Many of the shops that have done this are doing high-end performance work and can charge a premium for their services. They've earned a reputation for top quality work and have a dedicated customer base.
CNC equipment also has a place in high volume shops where automation can improve productivity as well as consistency, quality and profitability. The more complex jobs can be programmed and done automatically using operators who do not have to be highly skilled machinists (which are hard to find). This can reduce the shop's labor costs and overhead, allowing it to price its rebuilt engines more competitively.
If you're in the market for new equipment and are considering a dual-purpose machine or a CNC multi-purpose machining center, don't just look at the price. Look at all the features the equipment has to offer (including optional fixturing and tooling), and what the benefits of these features might be in your shop. And think outside the box.
What exactly do you want the machine to do?
Will the machine give you capabilities that you don't have now?
How can those capabilities be used to improve your business?
Once you've found a machine that fits your needs (and budget), try it out to experience for yourself how it works and what it can do. A quick demonstration at a trade show is not the same as actually mounting a block or head in the machine and doing some real work on it.
Are the controls easy to understand and use?
Is the tooling easy to change and setup?
Is the machine accurate?
If you're happy with the machine, and it offers the versatility, profitability and funcionality your shop needs, then buy it.
The following equipment suppliers currently offer dual-purpose machines and/or CNC equipment for automotive applications:
CNC MACHINE SALES
Steve Demirjian says CNC Machine Sales, Orange, CA, offers a variety of CNC milling centers and turning lathes. The two models of most interest to our readers are the Block Pro 4220 and 5260.
"The 4220 is a basic CNC multi-purpose machining center that is more than enough for most race shops. The 42 has a rigid vertical spindle with 40" by 20" of travel. The larger 5260 is for big diesel engines and has a travel range of 50" by 26"," Demirjian explained.
Demirjian says both machines come with "flood cooling" system, which is something many other CNC machines do not offer. "We use Dynapath CNC controls, which allow you to make billet parts or do conventional machining."
The Block Pro 4220 sells for around $78,000 and up depending on tooling, probes and other options.
Randy Neal says CWT Industries, Norcross, GA, currently sells a "Pro Series Bal-Mill 1000" that can be equipped with CNC controls for three and four axis machine work. With the proper tooling, the machine can be used to mill or bore engine blocks. The base price of the machine is $20,000, and goes up to about $60,000 with tooling and fixturing.
Haas Automation in Oxnard, CA, has two CNC machines that can be used for various kinds of work: its "TL" Toolroom Lathe and "TM" Toolroom Mills. Both machines come with CNC controls and traditional manual hand wheels, and have a base price of around $20,000. By adding various tooling and fixturing, the machines can be used for a wide variety of applications that require turning, boring, milling or machining metal.
PETERSON MACHINE TOOL
Peterson sells an AC650M combination milling/boring machine that can cut with carbide or CBN and handle bore sizes ranging from 2-1/2" to 6" in diameter. The combination machine starts at $32,500 and typically sells for around $40,000 with tooling. Digital readouts are available but no CNC controls.
"We don't have any CNC controlled equipment right now," said Chip Brown, "But we will be unveiling a new CNC machine at the upcoming Performance Racing Industry show in December."
Brown said there are a lot of good CNC machines on the market, but the biggest issue in his opinion is fixturing. "A machine may have a lot of capabilities, but can it handle a variety of different block sizes? Can it do both blocks and cylinder heads? We hope to address these issues with our new equipment."
RMC Engine Building Equipment, Saginaw, MI, sells several "V-Series" CNC machining centers. The machines have fixturing, tooling and three-axis CNC controls for boring blocks, decking blocks and heads, cutting lifter bores, O-ringing blocks, machining blocks for increased clearance with stroker cranks and more. The machines use a 360-degree rotary table so they can cut any surface.
"You only have to set up the block once," said Matt Meyer. "And once you set your zero point, you can go. With dedicated machines, you have to refixture and reset the block every time you move it from one machine to another."
The V20 is RMC's entry level machining center that typically sells for $67,000 to $69,000 with tooling and comes with a manual rotary table. The V30 is a bedmill machining center with a rigid spindle and fully automated 4-axis CNC control. This model is the most popular one that RMC offers and typically sells for around $90,000. It is not enclosed and allows easy access to parts that are being machined. The V40 is a fully enclosed, fully automated CNC machining center. This top-of-the-line model comes with a 24-pocket tool changer and typically sells for around $120,000.
Rottler Manufacturing, Kent, WA, offers two types of multi-purpose machining centers. The new F67 series is for boring and milling passenger car/light truck engines, and is available with or without fully programmable 3-axis CNC controls. There is also a CNC programmable 4th axis auto rollover fixture for more advanced machining functions such as block lightening. The unit offers variable speeds and feeds and easy-to-use conversational programming as well as a Direct Motion CAM (Computer Aided Manufacturing) which allows parts to be designed at the machine and made right there.
The F67M manual version typically sells for $45,000 depending on tooling and fixturing, while the F67A CNC version can cost up to $120,000 depending on options. The F67M works as accurately as the CNC version but with hand wheels, joysticks and digital readout.
Rottler's unique connecting rod fixture allows both big and small ends to be bored in one set-up, resulting in perfect parallelism between the bores and the center-to- center distance can be programmed for very accurate rod machining.
For larger diesel, marine and industrial engines, Rottler has the F88 Series multi-purpose machining centers. The F84 model can handle big inline sixes and V8s, while the larger F88 can accommodate the largest V16 marine and natural gas engines. This huge machine tool can handle boring, surfacing and line boring as well as large connecting rods found in natural gas compressors. These units sell for $85,000 up to $300,000.
Sunnen Products Company, St. Louis, MO, has entered a marketing agreement with RMC and will be marketing RMC's V-Series CNC machines under the Sunnen/RMC banner.
Sunnen also sells its "Sunnen/DMC HMC-3000" combination valve guide and surfacing machine. This is a manual machine (no CNC controls) that can do block surfacing and boring as well as valve guide and seat work. This unit typically sells for $68,000 to $70,000 depending on options.
Sunnen's Tim Meara says, "Fifteen years ago, everybody wanted dedicated machines, but now they all want universal machines or machines that can do more than one thing. So we've added an align honing attachment to our "SV-10" line boring machine to make it a dual-purpose machine.
WINONA VAN NORMAN
Ed Kiebler of Winona Van Norman, Wichita, KS, says, "Most of the shops who can afford CNC equipment have already bought it, so we're offering manual equipment that's more affordable for the average shop."
The "VB120" is a multi-purpose combination boring/milling machine that comes with digital readouts, infinitely variable feed rate and rpm, and can bore cylinders from 2" to 6" in diameter. The unit sells for $34,995 completely tooled.