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Transitioning the Die Shop- Can I Do It Successfully?
Transitioning the Die Shop- Can I Do It Successfully? By: Jim Szumera - MACOR Published on: 08/26/2014
Transitioning Your Die Shop- Can I Do It Successfully?

The reasoning for making such a transition must be based on necessity. That necessity is the lack of expertise remaining in the marketplace coupled with the need to be more competitive. Do I need tool and diemakers to keep my shop functioning from a die maintenance and production standpoint? What do they actually do that cannot be done by others not in the trade? Do I need to pay someone $25-$30 an hour to stand by a surface grinder and watch it go back and forth. Do I need special expertise to drill a 1/16 diameter hole through a 1 inch block of steel? If I have qualified tradesmen, why am I still working overtime? A good example of transition are the medical offices throughout the country. They have transitioned their practices completely and successfully, utilizing medical technicians and assistants. The technicians and assistants carry out many of the daily tasks required. In fact many medical outlets rely solely on technicians.

The main focus in a manufacturing transition should be your production expertise. Are your production parts complicated. If so, what makes it complicated? Is the majority of parts symmetrical? Are they round? Is there a great variation in part geometry? What are the tolerances required? These conditions need to be analyzed to determine what degree of competency is needed to facilitate maintenance and production.

The next critical area is control. What controls do I have in place now? Do I have the proper documentation covering all processes, both production and die maintenance. Many companies only go as far as meeting there customer requirements for traceability and documentation that they totally overlook controlling the in house processes such as die maintenance. Is quality engaged in all facets of production?

If these 2 topics, control and complication, meet criteria, you are probably in a very good position to move forward in the transition. Change is never easy. Through the past, many of us have come to completely depend on the expertise of the Tool and Diemaker, but the fact is that expertise is now running on empty. Our next articles will cover the actual tasks, choosing the right people and enabling them to perform to their optimum consistently. We will also address sustainability for the future and how that is enforced.
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Runnining Older Presses
Runnining Older Presses By: Jim Szumera - MACOR Published on: 06/23/2014
Tips and Tricks to Producing Quality Parts in Older Machines
Oftentimes I fall into the blame game. Is it the press? Is it the die? I have had new dies installed into presses only to make several hundred hits before the punches would shear. I have had draw dies set up resulting in cracked cups, wrinkling on one side only, galled and sheared. The initial tendency is to address the problem as a tooling issue; after all, it was the tool that failed. If the tool is machined and set up correctly, it can never be a tooling issue. The root cause often lies elsewhere. If a tool fails shortly after set up, one needs to look closely at the press variables. These can be alignment, wear, parallelism, speed, stroke, timing or lubrication. One of the most critical performance criteria is press alignment. Older presses, through neglect, age, off center loads, constant area loads and the floor foundation itself all contribute to miss alignment. Several simple checks should be made to determine the press accuracy and alignment. First, the surface of the bolster and ram need to be checked for flatness. After years of pounding, the ram and the bolster may have an area of impression. A good rule of thumb is .001 per linear foot. Any more than that is trouble. The bolster may have to be reground if it shows excessive depressions. The ram also may have areas of depression. Resurfacing the ram may be too costly and time consuming. To compensate for the ram I may elect to “soft mount” the upper shoe using a hard urethane sheet between the ram and the upper shoe. This acts as a “filler” and will compress slightly on the down stroke. Another method is to mount a pre hardened 4140 plate to the ram, provided you still have adequate shut height. Basically we are installing a new surface to the ram. All high volume heavier material stamping dies should be designed using a 4140 steel die shoe to begin with. The higher strength material will prolong the surface life of the ram and bolster. Using 4140 for the die shoe, in many cases, will allow the elimination of back up plates. That savings will more than offset the increased cost of the shoe. The lower shoe must be supported all the way through the bolster, wherever there are large cutout areas. I have actually encountered a lower die shoe so flexed that the shims behind the bushings slipped under the die block. In another case, slugs actually slipped under the bushings. The die shoes also need to be checked for excessive bending and corrected as necessary. If you are stamping thin materials, you may not experience these types of issues. Short of rebuilding the press, I will modify the tool to improve alignment and prevent shearing, galling or breakage. If I am dealing with older presses I may design my tooling with guided strippers and no press fits. On draw dies, I will allow the draw punches to float and find their own center. This will always make for a better looking even draw. In some applications, involving high speed dies, I will not bolt down the lower shoe. It is allowed to float. Any modifications to mounting methods should be done in a safe and protected manner.

We have listed several ways to help correct the press inaccuracies such as installing pre-heat treated plates to the upper ram, regrinding the bolster, supporting the lower shoe, and various tooling corrections. Other issues that can cause die failures are crank and pitman timing on double crank machines, galling of the press slides and gibs, short guide pins that exit the bushings on the upstroke. This usually results in deflection and “bounce” on the down stroke. The crank assemblies can be out of timing with respect to each other. Another critical component are the isolation units under the press feet. Are they worn or collapsed? The floor foundation is another factor. Does the entire press flex on the down stroke, given the weakness of the floor foundation. I have had instances where the floor was cracked between the press legs and actually flexed. In the idle state, the press checked out fine. Another issue that rears its head slowly is with open back incline presses or OBI type. These presses can "yawn" or open more in the front over time. It may be necessary to actually shim the front of the bolster to compensate. In any case, if you have evidence of press degradation you must set up a plan to address these issues. The plan may include increasing inventory, outsourcing, or running in optional available machines giving time to rework the press, and planning for new presses in the future. You cannot keep running presses in poor condition and expect quality parts every time. Post your ideas.
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The Seven Deadly Sins of Metal Stamping
The Seven Deadly Sins of Metal Stamping By: Jim Szumera - MACOR Published on: 04/14/2014
The Seven Deadly Sins of Metal Stamping
1. Overtime is one of my biggest expenses. I frequently work overtime in order to catch up or repair breakdowns.
The root cause here can be several factors. Production planning may be lacking the ability to properly plan production. This can produce delays and shifts in die maintenance resources. The tools may not be adequately designed to handle the existing requirements. They may be poorly designed to begin with. The die maintenance process lacks procedure. Spare tooling may not be available. This can be caused by premature tool wear and not realizing the full capability of the tool for various reasons. Bypassing press controls such as miss feed detectors cause die damage and tool breakage. Any overtime should always be scheduled and contain specific goals or achievements.
2. My tools do not produce good parts the first time in the press or they require constant adjustments. I live in a “hit or miss” production environment.
The hit or miss environment can be caused by running the same tool in different machines and each time a change is made the die must be married up to that machine, either with shims or grinding. There is no procedure or set up process. The tool is serviced in different ways by different people who can cause variances. No process in place. No tooling checks.
The raw material itself can cause part variations. This condition also contributes to overtime expense.
3. I miscue in communication or “hand offs” between shifts and personnel causing tool breakage or unnecessary downtime.
This usually happens because of a lack of a clearly written or oral plan that is understood by all.
4. Tools seem to be incapable of completing production releases for various reasons.
This can be caused by running the tool above its recommended rate. Running tools too fast can cause miss hits and tool damage, especially to fragile components. It can also be caused by inferior design or inadequate tool steel wear components. The part may be toleranced to close or incorrectly to account for any mechanical fluctuation in the raw material properties. Bypassing press controls such as miss feed detectors cause die damage and tool breakage.
5. I have to slow the press speed, or perform various tricks in order to make acceptable parts.
Again, the rate of production may have been pegged too high in the first place. It takes time to move or form metal. The tool set up procedure may be lacking. The raw material may not be to specification.
6. I am frequently “overproducing” when the tools are running good in order to get a “cushion”.
Production control usually develops these habits caused by fear from the tools history. Over time, this can cause inventory to rise across the board.
7. My production control department cannot schedule jobs in real time for fear of missing delivery dates. The ‘everything is hot” mentality takes over, usually plant wide.
Most production control departments usually pad their actual requirements, thinking that affords some kind of guarantee to make delivery.

All of these sins can be eliminated over time. It takes dedication through a cultural change within the organization to break these cycles. You can’t take it personal but first a company must be able to see itself as others do. The question becomes where am I now and where do I want to go? What are my obstacles to success? Where do I put my investment dollars? Is it mostly in the “front office” and not in the back end or production end? Is money spent on the finest conference tables and computer systems available, while at the same time trying to find the lowest cost tooling available, with the belief that lowering those costs puts more money in my pocket? Do I have a written plan to replace or upgrade tool room and production machinery? Do I execute on that plan? The culture change must also involve having the right people and processes in place, with a strict adherence to those processes. These are only a few thoughts about addressing the issues in today’s stamping plants. Each company has its own unique set of problems and the message here is to be able to recognize and eliminate those problems or obstacles. For more information about what you can do specifically contact Jim Szumera at szu@macor-wiz.com.
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Comments

MelvinMay 5, 2014 - 9:11 am
"Greed, compliance, poor quality, no forward thinking just to name a few."
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