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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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Survive and Prosper Without Tool and Die Makers
Survive and Prosper Without Tool and Die Makers By: Jim Szumera - MACOR Published on: 03/31/2014
Can your business succeed without tool and die makers? Does your business and virtual existence rely on the expertise of the tool and die maker? If you are a manufacturer of metal stampings and assemblies the answer is obvious. In today’s ever changing manufacturing landscape, these resources have been depleted to the point of extinction. We just don’t know it yet. In 15 years, give or take, most metal stamping in this country will have moved offshore somewhere. This time it will be necessary and permanent. Unless a new paradigm affecting our business model is created, it’s over. Recognizing that the tool and die trade is no longer viable and that the tradesmen are gone, or soon will be, a transition into a new hybrid business model with a new culture must take place. Survival depends on it.

In making any transition, I like to look at the entire process, from estimating, design, die building and production. I analyze the manufactured product and the tooling. Is it symmetrical? Is it complicated? If so, what makes it complicated? Can it be simplified? What are the quality issues? What are the production issues? In running the shop, are the tasks redundant? Analyze the tolerances, methodologies, and capabilities. In most cases, the expertise needed and required to maintain tooling is minimal, especially with repetitive tasks. Tooling technicians can fill any expertise gap in the shop with minimal training as compared to the formal training of the tradesman. A great starting point would be to use the 80/20 rule and choose the production tools that produce 80% of the business. An in depth tooling PFMEA should be created for these tools and all associated issues. I am not talking about the cursory, half written, PFMEA that is currently on the shop floor, most likely in the production area. I am talking about a comprehensive new document and road map for each tool. Knowing what to do, when to do it and how to do it becomes a lot easier. Grinding and operating shop machinery is circumstantial. Where do we find these people? Most shops have the qualified people in place now. They can come from the production floor (press operators), quality and inspection. These people already are familiar with and know the tooling and the parts. They recognize the quality issues first hand. The focus is starting with a clean slate. It’s a lot easier than you think.
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Comments

ClareApr 2, 2014 - 8:43 am
"Hi, Jim - Good editorial! My father was a journeyman Tool & Die maker, who worked for GE for 32 years, then took early retirement and started his own business. Very few of these true "tool & die" makers around any more. Even my brothers, who run the business now, aren't tool & die makers -- but are "managers" that leave the tool & die work to those out on the floor. My oldest son is actually a really good machinist who is now the quality manager for the family business. It's tough to find these guys anymore.
Clare"
EdApr 2, 2014 - 8:45 am
"I don't know how a stamping facility could survive without Tool & Die makers for any length of time. Eventually the tools will wear and someone will have to be able to repair them. I do believe that the skill level necessary is not what it use to be. I remember starting in the trades and hearing the the trade wasn't going to be around for long and that was back in the late '70s. I also know with the machining capabilites now, replacement steels are easier to manufacture, maybe less need for shimming and sharpening. But you will need somebody to trouble shoot at some point."
JeffApr 2, 2014 - 10:15 am
Why are they gone Jim?? Do you think it might be because we undervalued and underpaid them for 3+ decades and decided to place value in other places within the business? why? In a free market where supply and demand rule how is it that tradesmen have somehow never won out? It's like a hospital where doctors get paid less than accountants. We would be flush with tradesman and apprentice's if we would simply reward them($$) according to the value the provide for the company. Instead the VP of whatever the flavor of the week is gets the 6 figure comp pkg. while those who's expertise actually puts meat on the companies table get treated like common laborers. We reap what we have sewn. Nice work pencil pushers of America!! can't wait to see where your jobs go and what you do when the tradesmen you've been riding for all this time disappear. Last time I checked the customer doesn't buy nifty powerpoint presentations.
DaveApr 2, 2014 - 2:29 pm
At least we finally get to read an honest assessment of the state of the metal stamping business. Tired of reading the sunshine articles about reshoring initiatives, government and manufacturing cooperatives, lean manufacturing schemes, and breakthrough technologies that are all supposed to save US manufacturing. The fact is that so much of the industry and it's supporting network is gone that any revitalization will take more than a generation to rebuild. Those us that remain will have to find niches of prosperity and be able to operate under the leanest of margins.
VincentApr 3, 2014 - 8:21 am
"The list of factors leading to the decline of tool and diemakers starts 40 years back with the basic premiss of skilled craftsmen not wanting "their kids to do this work" but also the political landscape, educators and industry itself. Take it offshore, don't get your hands dirty, why work in a factory? If you are of right generation, it was the tool and die makers that stayed to build an American war machine, Rosy was there too but so were the skilled tradesmen. I came from a family of manufacturing tradition and married a tool & diemaker trained by the "German's" that emigrated to America after the war. The Reshoring inititative and pockets of economic recognition of the "wealth" these jobs create is finally being seen. Schools are coming back on board. Manufacturing facilities open their doors to politicians to see the latest and greatest in technology. There is "Made in America Pride" and kids are being exposed to new opportunities. But still the mssing link is APPRENTICESHIP; 4 years of mixed skills and a college education is needed to meet today's challenges. Keep the handles on the toolbox to be a JOURNEYMAN. THERE IS NO SHORT CUT."
MikeApr 7, 2014 - 8:18 am
"Without any toolmakers? Perhaps with less than in the past, but no, not without. Plug & play works fine for making an assembly, utilizing CNC technology to it's fullest. It will even, in fact, look like a die. Will it produce good parts right out of the box? Occasionally, given enough tolerance that may happen, but most of the time a little tweaking is necessary. Should we guess by whom? I would venture to say it would be by a tool-maker. Just my 2 cents, your mileage may vary."
MelvinMay 5, 2014 - 9:10 am
"Everything that you touch or see has the skills of a tool maker, if we as a country don't get on the band wagon we will be begging other countries to make our products and they will tell us what we can make !!!!!!!
"
IanJul 21, 2014 - 12:07 pm
Tool and die makers are indeed a dwindling resource, but in the Ontario market at least - this seems to stem from a lack of stamping / die form operations left in the province. Many tool and die apprentices I went to school with have transferred into the machinist stream in order to take advantage of the percieved lack of qualified CNC operators / programmers around here. That being said - those who continued through and got their tool & die ticket haven't seen any shortage of employment opportunities thus far!
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