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Getting started with QDC.

An organized, common sense approach can go a long way toward minimizing hit-to-hit time in stamping operations.

The "80/20 rule", like Murphy's famous law, has many variations. One of the most well-known is the rule of thumb that says about 80% of the work in a given organization is done by roughly 20% of the workforce. Then there's the axiom that you can achieve 80% of the benefits of a desired outcome by expending only 20% of the resources needed to gain the full 100%.

The trick in the latter situation, of course, is figuring out the right 20% to spend your resources--time, energy, and manpower, as well as financial--on. In the case of quick die change (QDC) for stamping presses, it's possible to achieve many of the benefits of a full-blown QDC system without large investments in die staging stations, positioning devices, and clamping systems. (Those of you interested in QDC equipment, however, can turn directly to the sidebar that accompanies this article.)

QDC: who needs it?

You do, whether you're operating a transfer line for dedicated production of automotive sheet metal components or a small job shop cranking out stampings for a hundred different customers and applications.

"I strongly believe that QDC is not just a gimmick to reduce inventory or whatever...it's really a manufacturing strategy to reduce overall costs in the plant," says Gary Zunker, president of Nicholasville, KY-based QDC consulting and equipment company Lightning Time Savers.

"Companies that go to (QDC) will be around 15 or 20 years from now, and the ones that don't aren't going to be around," adds Mr Zunker, who has been involved in implementing QDC as an industrial engineer and consultant for 10 years.

He offers as an example of what QDC can do a company that was operating a press seven days a week, three shifts a day. The job shop was running small lot sizes and was doing six to eight changeovers a day with hit-to-hit time of 90 minutes per changeover. Machine utilization was about 20%. After implementation of a QDC program, hit-to-hit time decreased to 9 minutes.

Such a dramatic reduction in setup time requires equipment investment, such as ball transfer tables, bolster rollers, and quick-change clamps. But, Mr Zunker says, a good portion of the benefits of QDC can be achieved through careful organization and planning of a pilot program.

The thing to keep in mind is that QDC is more than equipment. It's a philosophy. The basics revolve largely around organization and common sense. Here are some tips on how to get started with QDC without large equipment investments.

The team's the thing

One of the keys to successfully implementing QDC is enlisting the support of key shop personnel, from top management to press operators. A cross-functional QDC team should include operators, foremen, schedulers, and setup, tool room, engineering, and management personnel.

The team approach builds acceptance of QDC throughout the organization. Cooperation from departments throughout the shop is enhanced, and consensus decisions made by the team generally result in sound, readily accepted ideas.

As important as it is to have representatives from throughout the shop on your team, it's also vital to designate a QDC project manager. The team leader should coordinate the work of the team and report to management.

Each team member should fully understand and support the need for quick die change. Resistance to change is a natural human reaction, and team members with no clear idea of the strategic importance of QDC can limit the effectiveness of any efforts. A commitment from management that employees' jobs will not be affected as a result of manufacturing improvements can help to allay fears and obtain not just cooperation but commitment to QDC.

Everyone involved also should understand that they're being asked to work smarter, not harder. "Most people believe that, because they're going to be doing more changeovers than they used to, they're going to have a lot more headaches. That has to be turned around. You're going to address the headaches before they occur and eliminate them. You'll end up being much more flexible as a result without nearly as many problems as you have today," says Mike Austin, vice president of sales for Atlas Technologies Inc, Fenton, MI.

Press for success

The team's first task should be to select a "doable" pilot project and clearly define goals. The pilot project should involve a product family that will have a significant impact on company costs. After a candidate part family is selected, a press or a couple of presses should be chosen for the pilot project. If multiple presses are to be used, they should be similar in design and capacity.

Another consideration in choosing a pilot project is not only to pick one that will have a positive financial impact, but also to choose a project that has a good chance of succeeding. Look for a press group that will require minimum tooling changes, has operators that are open to new ideas and willing to get involved, and is in reasonable overall condition.

It's important for both shop floor and management personnel to see that QDC can make a quick, positive impact on operations and costs. Goals for the pilot project should be reachable with existing or attainable resources, and must be clearly defined and quantifiable.

Benchmarking

Once a realistic pilot project is chosen and measurable goals are defined, the next task is to complete a detailed inventory on current equipment and procedures for the press or presses chosen for the pilot project. Data on die sizes and weights as well as information on number of die changes, length of production runs, which dies are used on the presses, and time currently spent on die changes, should be compiled.

A good way to begin analysis of current diesetting practices is by videotaping one or several die changes. Using a video camera gives the team the ability to review the setup as many times as are necessary. This facilitates the next phase of the QDC project, which involves analyzing and classifying current procedures.

The ins and outs of QDC

During video review, individual tasks can be time studied and details of each segment of the setup recorded. Each portion of the changeover procedure should be studied and classified as either an external or an internal activity. External activities are those that are (or could be) performed while the press is completing the previous job. Internal activities are those that cannot be performed until the press is shut down. Much can be accomplished with some planning and organization. Everything--from material and production control to making sure the right nuts, bolts, and tools are available--is a candidate for improvement.

The foreman or scheduler, for example, can line up a job on the press while the previous job is being completed. This allows time for the lead person or the assigned setup person to check stock availability, make sure the die is clean and has had any necessary maintenance, and is ready to be moved to the press before the other job runs out. Shop orders, setup sheets, and any other setup documentation should accompany the required tooling for the next job, as should part move tickets, a clean part print, and the last good piece from the previous press run, to facilitate first-piece inspection.

Internal procedures can be speeded up by using teams similar to auto racing pit crews, with each person having assigned, clearly defined tasks. For example, there might be people in front of and in back of the press to loosen and tighten bolts. The rear person would also clean the bolster, remove slugs, and clean up the area. The front person would remove the old die and insert the new one. A third person could make sure the needed materials and stock containers are at the press.

When the die is set and the area cleaned, all the crew members except one go back to their normal responsibilities. The assigned person gets production approval and gives operating instructions to the press operator.

Practice, practice, practice

Careful analysis of procedures and some well thought out changes should yield significant results fairly quickly. Decreases in hit-to-hit time of up to 50% are possible, according to Mr Austin. "Most people can knock 50% off (press changeover) time without spending too much money, strictly by motivating their people and being better organized," he says.

Practice beyond just regular press changeovers, however, is vital to get team members working together more smoothly. Mr Austin recommends taking advantage of scheduled downtime, weekends, or any other available time to practice tooling changeovers. "It's hard to learn how to do something if you do it once a week as opposed to doing it 20 or 30 times in a row," he says.

Move toward standards

So far, not a dime has been spent except for team meeting time. Even a modest pilot program for QDC, however, will benefit from whatever standardization of tooling the budget will allow.

Steve Stultz, sales manager for Sytech Engineering Inc, Elk Grove Village, IL, says one relatively inexpensive way to standardize dies with varying designs is to fabricate or purchase a few common subplates. "What you're shooting for is a standardized front-to-back and thickness," he says. "Most companies can make subplates themselves cheaper than we can do them." Depending on die size and application, subplates can run anywhere from $150 to $500 per die.

Standardized dies mean you can use standardized clamps, minimizing loose hardware such as parallels, washers, straps, and setup blocks. The result is more time savings. Standardization also can help avoid damage to dies and other hardware during setup.

Plan ahead

With careful planning and organization and a minimal investment in hardware, it's possible to achieve substantial reductions in press setup time. The success of your pilot QDC program can serve as a springboard for expanding QDC to other shop areas and presses, or as a lever to free up some dollars for purchasing the hardware that can help you wring maximum productivity from your existing presses.

QDC equipment suppliers

The common-sense approach to QDC outlined in this article can give you a good start, especially in a job-shop environment. Maximizing benefits from QDC and minimizing changeover times, however, require some degree of automation.

There are several "full-service" suppliers of QDC products and services. These firms generally have broad product lines and offer services ranging from design and engineering to project management and training. Some companies specialize in equipment for a particular aspect of QDC or quick press setup, such as die carts, clamping, or accessories such as tonnage meters. Here's a sampling of some of the QDC products, equipment, and services available:

Lightning Time Savers, Nicholasville, KY, is a consulting firm that handles all phases of QDC from concept development to engineering of complete turnkey systems. Available products include die rollers, clamps, and carts; ball roller die tables; die storage systems; die manipulators; and milling services for press modifications.

Another full-line supplier of QDC equipment and engineering services is Sytech Engineering Inc, Elk Grove Village, IL, which offers such products as pumping units for hydraulic clamping systems, hydraulic clamps in a variety of styles, die lifters, bolster extensions, die carts and trucks, and pre-staging racks. The company also provides consulting, engineering, and installation services.

Atlas Technologies Inc, Fenton, MI, has complete services ranging from defining QDC system needs to designing and manufacturing customized systems. The firm's product offering includes bolster extensions, T-tables, custom-designed die carts, and die racks.

Enerpac Inc, Butler, WI, offers a range of products including die lifters, pressure control switches, air/hydraulic pumps, clamping bars, and die separators. Also from Enerpac is the QDC-5 self-contained power system that includes an air/hydraulic pump, electrical control valves, system gages, and pressure control switches in a compact control box.

Orchid Automation Systems Inc, Fenton, MI, is a supplier of large, automated die-handling systems and multi-level storage systems. The company also provides automated die opening, separating, rotating, and washing systems.

JIT Automation Inc, Scarborough, ON, markets self-traveling clamps for large presses, hydraulic piston and lever clamps, valves, power units, and control panels. The company also offers mechanical die fixing systems that allow rapid die change with repeatable positioning accuracy of 0.0008". System components include die holders, presetter fixtures, standard die plates, and mechanical clamps.

American Aerostar Corp, Sylmar, CA, designs and manufactures clamping equipment, die lifters, and bolster extensions. The company's model 825 Power Strap hydraulic clamp accommodates a range of die grip heights and exerts 8000 lb of clamping force.

AeroGo Inc, Seattle, WA, is a supplier of die trucks and carts for specific applications. The firm's latest sideloading, all-wheeled die truck travels in all directions, including rotation about the center. The battery-powered truck can lift dies as heavy as 40,000 lb to storage racks up to 13 ft high. The vehicle features a "fly-by-wire" joystick that replaces the standard steering wheel to provide better control for handling very heavy dies in tight quarters.

Toledo Transducers Inc, Toledo, OH, is marketing the Die-Try portable tonnage meter for documenting press tonnages. The unit works with sensor-equipped presses by plugging directly into the sensor junction box mounted on any straight-side or C-frame press, and features an on-board memory that recalls calibration settings for up to 100 presses. Digital displays show total tonnage, tonnage distribution, and peak tonnage for the press stroke.

For information from companies mentioned here, circle the appropriate numbers:
Lightning Time Savers Circle 331
Sytech Engineering Inc Circle 332
Toledo Transducers Inc Circle 333
JIT Automation Inc Circle 334
Enerpac Inc Circle 335
Atlas Technologies Inc Circke 336
American Aerostar Corp Circle 337
AeroGo Inc Circle 338


Orchid Automation

Systems Inc Circle 339
COPYRIGHT 1992 Nelson Publishing
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1992 Gale, Cengage Learning. All rights reserved.

Article Details
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Title Annotation:includes related article; quick die change
Author:Destefani, James D.
Publication:Tooling & Production
Date:Oct 1, 1992
Words:2290
Previous Article:Broaching fires up competition.
Next Article:Video makes it better.
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