As the values of advanced machining technologies continue to increase, it becomes apparent that the highest returns on investment in such technologies are realized when related needs like these are put into practice:
- The need for advanced management of technology selection, including well-defined manufacturing goals and a clear action plan to achieve the objectives,
- The need for more penetrating evaluations when selecting new technology, and
- The need to practice higher levels of teamwork in order to maximize utilization of the technologies selected. This includes teamwork not only among various functions within the same manufacturing company, but also teamwork among outside parties responsible for a given technology's application and development.
Our experience at Rockwell Automotive Specialty Products Division in Oshkosh, Wisconsin illustrates how the three needs are being addressed in order to maximize return on capital investments.
In a program to modernize our manufacturing operations--the Rockwell/Oshkosh Re-Design Program--an overall goal is to consolidate all machining operations performed on certain products within a given physical area. One purpose of this is to enable people to know the operations performed upstream and downstream from their own. Another purpose is to help people see firsthand how all the operations performed in their area affect final assembly.
A movement as wide-reaching within a company as our Re-Design Program naturally requires time and money investments of substantial magnitude. In turn, these investments require searching out the manufacturing technologies and related support that will raise productivity and quality to the levels that meet designated payback schedules.
Toward this end, one of the most valuable ingredients for success is what we have come to call "plant floor partnerships." Despite our reference to "plant floor," the focus on teamwork originates at our executive management level.
In the Re-Design Program, for example, Rockwell/Oshkosh general manager Bill Evans and operations manager Jim Barrett have given us more than just the dollars. They also give us their full confidence--let those responsible for production select their own methods, machinery, tooling and people. When management is willing to delegate such a high degree of responsibility, it's human nature to make certain their confidence is deserved. "Making certain" includes absolute thoroughness in evaluating, selecting and applying new technology.
This example of how much plant floor partnerships can pay off involves a team of our own Rockwell people plus representatives of Kennametal tooling, Giddings & Lewis Automation Technology and that company's distributor, Marshall & Huschart.
Rockwell/Oshkosh faced a fundamental need for more horizontal turning capacity--with specific needs for higher turning productivity, reduced setup times and higher product quality.
As a start, we formed our own internal team to evaluate and select the turning technologies most likely to help us meet our goals. Members of this interdisciplinary team included the shop-area supervisor, general foreman, two machine operators, programmer, maintenance supervisor, mechanic, purchasing agent, tool designer and industrial engineer.
Five Basic Stages
Our internal team performed the evaluation/selection process in five basic stages.
First, eight manufacturers of horizontal turning centers were invited to submit "basic quotations" in response to the machine requirements we had outlined for spindle horsepower, machine travels plus 40 to 50 other parameters.
Second, we screened the eight responses. Price was not a factor at this stage. Our need was to learn who offered machines that could do the job. On this basis, three of the original eight sources were ruled out because the machines were not appropriate for our application.
At the third stage, we looked at price. Two sources fell off the list, so three candidates remained.
In the fourth step--requesting a final quotation--we gave the remaining three candidates an "Attachment II" form that identifies a large number of machine requirements specific to Rockwell International Corporation. Typical specifics include machine safety devices, machine-mounted instruction plates, and so on.
In addition to providing information, our "Attachment II" form has become a reliable indicator of how much value our people can expect from each machine builder's future participation on our factory floor. Participation includes not only start-up assistance, but on-going involvement to help us optimize the technology supplied.
In the fifth stage, we evaluated final quotations and made the selection. In this case, the consensus of the ten Rockwell selection team members was to choose two SmarTTurn H15 four-axis horizontal turning centers (HTCs) from Giddings & Lewis (Fond du Lac, Wisconsin), equipped with KM 50 quick-change tooling from Kennametal (Latrobe, Pennsylvania). The two HTCs operate adjacent to each other, with one operator tending both machines.
Our need for additional capacity and higher productivity was answered by such machine features as 56 hp with a 77-hp duty cycle, spindle speeds over 3,000 rpm and bedways that are 4.5 inches wide. On some of our automotive specialty components, these machines hold tolerances as tight as ±0.0005 inch.
Obviously, the way to realize the fastest payback from this combination of advanced turning technology is to keep both machines producing chips without being stalled by tool changeovers. That is why we went to quick-change tooling.
On a typical workpiece such as hub disks, the Kennametal KM 50 quick-change tooling has reduced previous machine setup time per job by 20 to 30 minutes. Because both machines work together, we now save 45 minutes to one hour per lot in total setup time.
Using preset tool packages with the quick-change holders, the operator changes over tools for a new job in less than a minute. A tool-tip gage, with which each machine is equipped, automatically verifies correct tool position, and the machine cycle begins.
If there is any variation in tool size, the touch probe signals the computer numerical control unit to adjust tool offsets automatically to compensate. Turning has proven itself so uniformly accurate the first time that we have virtually eliminated scrap on workpiece setups.
Our previous "cut-and-try" times have been replaced with the confidence of "load-and-go." In fact, with probing for tool offsets in place, our operators had more confidence in these new machines after ten days than they had on the older machines after ten years.
Our internal team's decision involved more than the choice of turning center and tooling hardware. It also illustrates how far-reaching the rewards can be when you take the time and effort to judge qualitative traits of people who might be helping you put any technology to work.
We already knew our internal team had selected the appropriate turning technology. To make that technology pay off as fast as possible, though, it was time to test the teamwork between Rockwell/Oshkosh and our outside partners. The test was to solve a long-standing problem of chatter.
For years, our design of the previously mentioned hub disks--high-carbon steel forgings--had posed the problem of chatter. We had been able to eliminate the chatter by using solid carbide cutters in our boring bars. However, the higher priced carbides and problems with carbide shattering created expenses that we obviously wanted to eliminate.
With the new turning center and quick-change tooling technologies, plus the inside/outside team that helped engineer and configure that technology to our particular needs, we felt we could now solve our chatter problem. But it wasn't easy.
For one thing, the chatter occurred only during a rough cut on the bore of the hub disk. For another, different amounts of chatter occurred at different times. Throughout our search for the right answer, a recurring frustration was that so many attempted solutions were temporary. The chatter would go away for awhile but then come back.
Check Every Clue
Despite the "negative" frustration, an even more powerful "positive" led to ultimate success. That positive force was total teamwork among the representatives of all four parties involved: Rockwell/Oshkosh chief industrial engineer Marv Kuhlman, Kennametal's Mark Verbonsouer and Gary Fulcer, Giddings & Lewis' Dick Werdin and Mike Washkoviak, as well as Jordon Foltz from Marshall & Huschart, the local Giddings & Lewis distributor.
During this team's collective search for an answer to the chatter problem, the team took the following actions at least once:
- Tool scoring and rust were addressed,
- All tool pockets were disassembled, cleaned, greased and checked for wear,
- Programmers and operators made machine adjustments,
- Duplicate sets of tooling were tested off-site,
- Chuck jaws of different hardness were tried,
- Numerous grades and geometries of carbide were tested,
- Tools were changed,
- The tool pockets were changed and rotated,
- Shims were added for damping,
- Boring bars were wrapped with tape,
- Frequency readings were taken from the machine,
- A boring bar was welded into a pocket to simulate a solid bar,
- Vibrations were checked at various machine positions,
- Boring bar positions in the turret were changed,
- Each tool pocket bore was checked for position X and Y perpendicularity to spindle when in cutting position,
- Heavy-duty tool holders were tried,
- Heavy-duty clamping units were tried, and
- New machine turrets were installed.
In short, the team brought several viewpoints to the problem, leading them to a remarkably thorough investigation. This investigation culminated in success when Giddings & Lewis designed and built a heavier turret that eliminates the chatter on our previous problem part.
Keys To Successful Problem-Solving
As you might expect from dealing with such a stubborn problem, we learned many things about what makes any plant floor partnership effective. However, two group traits experienced from start to solution stand out as fundamental to achieving our success:
1.Problem ownership by everyone. Not one member of this plant floor partnership ever said our problem was the responsibility of someone else. Each person shouldered responsibility on their own initiative, and each made important contributions to the ultimate solution.
2.Strong communications. Communications remained continual and clear throughout every step of the way during this process.
Under these broad characteristics, other attributes of the team stand out as important elements in cooperative problem-solving. Some of these are common sense items, yet worth mentioning. Others may reflect the qualities of our particular team members. When this team worked together, it was our policy to:
- Define all tasks, large and small. The importance of well-defined goals and a clear action plan for overall manufacturing operations already has been cited. Within larger goals or objectives, however, the smaller tasks must be equally well-defined. Each person must have a clear understanding of what is expected from him and when it is expected.
At Rockwell/Oshkosh, we developed a "Who/When Chart." The chart identified who was to perform what tasks, and the date by which each task was scheduled for completion.
An obvious value of this goes back to maintaining clear communication. Perhaps not so obvious, but equally important, is the value of motivation. Putting personal names on a written list of tasks with targeted completion dates has an interesting influence on action. Most of us want to get our names off that list, so we get our assigned task done--on time!
- Stay positive. History keeps proving that most problems eventually can be solved. But history also suggests there will be more people around to help you identify problems than to help solve them. So an important self-reminder is: "Don't let the negatives take over." In other words, keep yourself and all team members in a positive mode. One effective way to do this is to keep everyone focused on solving the problem at hand. Along the trail to problem-solving, for example, you might identify a potential fix even though that fix isn't in your specific area of responsibility. One way to maintain positive focus is to ask those team members who are responsible for the given area whether they think a particular idea might help. Asking others for their opinion can be more effective than telling them what you would do. A question starts people thinking more directly in terms of a problem-solving response. Typically, their response adds value to the original idea, such as: "Sure, that idea could help, but this might be better...and we can do this, too."
- Stop, listen and look! When trying to pinpoint the source of a problem, common sense suggests talking to the people who are most directly in touch with that problem. They are the ones "living" with the problem, and normally have the best "feel" for what is happening, when it's happening.
First, ask these people to tell you what is happening. Then ask them to show you what's happening. Go out on the plant floor and observe the action. What someone tells you and what they show you may not turn out to be the same. The difference can save large amounts of time in arriving at a solution.
- "One thing at a time" saves time. In the natural hurry to solve a problem, it's tempting to apply more than one possible fix at the same time. Such haste actually creates waste if the problem is corrected, only to realize that you can't identify which of the several possible solutions is responsible.
Work As A True Team
As with so many other subjects, the difference between "teamwork" that is only given lip service and "teamwork" that is truly practiced often is the difference between falling short and success.
The plant floor partners identified here truly worked as a team--and not only during normal working hours. Each time a new fix was attempted on our chatter problem, all team members met at Rockwell/Oshkosh. They watched the bore of the hub disk continue to chatter. They listened to it chatter. They observed the effects of each attempted fix.
After each potential solution was applied, the entire group would ask themselves, "What can we do next?" Here, a first step was to identify and agree upon what was or was not still a possible cause of the problem. Items agreed upon as not the cause were dropped from further consideration.
Team members then asked themselves as a group what they could detect by surface observation, and what they could not detect. When possible causes not observable on the surface were identified, various tests for vibration and harmonics were discussed and decided upon by the group.
Another trait that makes our group a true partnership is the unrelenting and unselfish pursuit of the solution.
When a possible solution is applied to most "headache" problems, you get either a "yes" answer or "no" answer, and that's it. Not so with these people. They measured each attempt on its own merit.
After an attempted fix didn't solve our problem permanently, each team player would take the initiative to identify possible steps that he and his company might take. The group then would discuss relative merits of each suggested action, and arrive at a group consensus for prioritizing which additional actions should be taken first.
The previously mentioned importance of communications is fundamental to practicing true teamwork. While each member of this team took self-initiative to suggest potential solutions, each also maintained a very strong communications link. Most significantly, no one tried to make a show and be "the hero."
For example, each team member notified the others in advance of what actions he was planning to take, because he recognized that other team members might have some related actions to consider if a particular solution was going to be tried.
Sometimes when a team member was communicating a planned fix, the group recognized that a different team member would need to do something first in order to make that particular attempted solution feasible.
Team Persistence Pays Off
The results of our team persistence speak for themselves. Perhaps our experience can help others who are searching for problem-solutions -- whether or not implementation of advanced technology is involved.
The point is to work with qualified people who are committed to helping you select and apply any technology most cost-effectively. And when you can go the extra mile with a plant floor partnership as determined as the one described here, not only will your extra efforts pay off, but your technology investment also will pay back much faster.blog comments powered by Disqus