Self Proclaimed Die Expert

What is Stamping? What are dies?

2012-01-18T05:33:00.001-05:00

In a recent SME: Stamping and Dies Technical group meeting, we discussed the topic of Dies and Stamping "Basics". The technical discussion was lead by me (Eric Kam, The-Self-Proclaimed-Die-Expert) and was presented using WEBEX. The meeting, sponsored by SME Forming and Fabricating Community, is part of the Stamping and Dies Technical Groups monthly meetings and Technical Discussion Forum.

Dies on Prezi

In the coming months the group hopes to make it a regular event to host these technical discussions featuring guest panelists in addition to our own leadership. The panelists will cover a variety of themes revolving around Stamping and Dies.

Here is the calender of events for 2012, note that in some months topics as well as speakers will still need to be defined.

Invite to Join SME stamping and dies Technical group monthly meeting

2012-01-06T14:55:00.002-05:00

INVITATION

Stamping and Dies Tech Group Monthly Meeting & Technical Discussion

January 11 | 1:00 p.m. ET

Join us January 11 at 1:00 p.m. ET to discuss the various activities of the Stamping & Dies Tech Group, which is part of SME's Forming & Fabricating Community.

Agenda

Welcome and roll call
2012 calendar
Tech talk

Topics Covered

Stamping and dies basics
Define stamping versus forming
Define dies
Identify role of presses in stamping
Types of presses and dies
Identify progressive, transfer, tandem operations
Discussion of other die-based forming methods

Upcoming Themes

Tech group projects for 2012 and beyond
Open discussion

Register Now

Brought to you by the Stamping & Dies Tech Group, which is part of SME'sForming & Fabricating Community.

800.733.4763

SME: Forming and Fabricating, Stamping and Dies Tech group

2011-12-15T03:07:00.000-05:00

This past Wednesday (December 13th, 2011) Dean Phillips presented another informative webinar with an overview of Press Room Safety where he covered such topics as compliance, protection systems, and common oversights.

Not a Safe environment for stamping: Source YouTube

While a one hour overview is a far cry from a proper press room safety course it did highlight the things that people should be aware that they do not know. (Was it Rumsfeld who said "There is the known, the known-unknown, and the unknown-unknown"? If knowing is half the battle then it is important to realize that there are things that we might not know. Dean's webinar did remind us of some of the things that are easily overlooked when considering press room safety.

Soon the Webinar will be archived as a recording on the SME website at the following link:
Stamping and Dies Technical Group Webinar Archive
* the site is for members only so if you are not a member you can join here. a bargain at $125/year to be able to join such valuable webinars we offer for free.

SME: Technical Communities - forming and fabricating

2011-12-04T23:44:00.001-05:00

I have been posting about the SME and its Forming and Fabricating Technical Communities over the years, and realize that we may never have done justice to explaining what we are.

Some Basics: SME = Society of Manufacturing Engineers (not Small Medium Enterprise in this case)
Technical Communities = Virtual work groups made up of the members of SME

SME- Forming and Fabricating Technical Community on Prezi

Each technical community supports and focuses on a Major technical field within manufacturing. The community I work with is the Forming and Fabricating Community, where we focus on forming metal parts and fabricating products from those and other metal parts.

My personal focus has long been Stamping and Dies used to stamp metal, along with Metal Forming Simulation. More lately hydroforming and other novel forming methods for Sheet and Tube have also been loci of my interest.

Dies on Prezi

To find out more about SME check out SME.org

Free Webinar: Event Information: Press Room Safety Requirements

2011-11-28T09:35:00.001-05:00

Register for Free Webinar at SME

The Stamping and Dies Technical Group of the Forming and Fabricating Technical Community is offering a free webinar on the topic of Press Room Safety. Wednesday, December 14, 2011 1:00 pm Eastern Standard Time (New York, GMT-05:00) This Webinar is being presented by the Stamping & Dies Tech Group of the Forming and Fabricating Community.

Attendees will learn:

Press Room Safety
Die Setting Requirements vs. Lock Out – Tag Out
Control Reliability

The benefits include:
1. Safeguard Employees
2. Identify the potential hazards and OSHA violations
3. Minimize Risk Exposure

Who should attend:

Die designers, die technicians and die engineers
Press Room Managers
Safety & HR Managers
Six Sigma / Lean Engineers

Speaker information:
Dean Phillips is a sales engineer for LINK Systems Safety and Automation Controls. Since 1989, Phillips has been involved with the forming and fabricating arm of manufacturing. He has designed, serviced, installed and sold stamping presses, press brakes, shears and other forming and fabricating equipment across North America, Europe, Asia and the Middle East. Currently, he specializes in automation controls and assisting manufacturers with pressroom integration, die protection, tonnage analysis, automatic die adjustment and press monitoring, reporting and safety.

The webinar is Free to all SME members as well as any interested in joining SME.
Register for Free Webinar at SME

What is Simulation? Metal Forming Analysis

2011-11-16T15:39:00.001-05:00

At Fabtech today only a few people who have stopped by were even aware that their stamping processes could be simulated easily to prevent costly forming issues; e.g. Splits, wrinkles, springback variation, excess thinning, low surface quality, etc.

The Self-Proclaimed-Die-Expert would love to show you how it works. Even better see for your self with your own data. If you are at Fabtech today get somebody to send over your Part or Tool data as an IGES or STEP file and have one of the AutoForm (Fabtech booth 2904) engineers show you how simulation could address your stamping engineering and troubleshooting issues.

See first hand that simulation need not be "smoke and mirrors". It won't take a room full of PhDs to operate and can produce results that you can act on often in the same day or even hour.

SME members stop by to learn more about the Stamping and Dies Tech Group, Metal Forming Simulation Tech group, and the Forming and Fabricating community.

SME takes it's publishing digital and interactive

2011-11-16T12:25:00.001-05:00

The Tool and Manufacturing Engineer Handbook, a long time resource to SME members and non-members alike, has caught up to the current century (or at least the last). No longer shackled to the innovation of Gutenburg they are fully embracing the electronic creation, publishing, and distribution of this heavy collection of volumes.

TMEH from a weighty tome to a living breathing resource

Certainly, they had already started to sell the volumes as CD-rom, but now they will take it to the next level by launching a Wiki based system by which the members of SME can freely contribute, review, revise, and publish content to the WIKI. For those who might not know what a WIKI is it is a type of website that allows for groups of people to collaboratively create, edit, revise, and publish knowledge or content.

The idea is that the TMEH which was last revised in 1998, will be now available online to members. The content will also be available to be revised, added to, and otherwise kept upto date through the interaction of the members of SME and the website. If you find information that could be updated with new and more relevant entries, you the members of SME can login and submit new content. Your peers will be able to review the content and if the content is valid and publishable it becomes the newest, latest and greatest TMEH entry at the push of a button. No longer tethered to an aging hardcopy the TMEH users will be able to always have the latest and best information at their fingertips (cursor tips).

To find out more you can sign up for the introduction sessions via SME.

Thinking of Going to FABTECH: Be our guest

2011-10-26T15:40:00.000-04:00

Autoform Engineering GmbH Invites You to FABTECH 2011

Autoform Engineering GmbH would like to invite you to come join us at FABTECH 2011. Attend FABTECH 2011 as our guest. Register today for free show admission! AutoForm was founded in 1995 in Zurich, Switzerland. Since then, AutoForm has grown continuously and rapidly. The company is recognized as the leading provider of software solutions for die process engineering and sheet metal forming simulation. AutoForm software enables its customers to tremendously improve their product quality, cost and time to market. Today, AutoForm is an acknowledged industry standard at virtually every automotive OEM and leading supplier of tooling, stampings and materials worldwide. AutoForm’s mission is to provide leading-edge software solutions and best-in-class support to help its customers achieve outstanding success. Booth: MF-2904 Contact: Jody Gorski, Email: jody.gorski@autoform.com Phone: (248) 269-4000 Website:		We’re Exhibiting at FABTECH 2011 – Register for FREE show admission! FABTECH 2011 is North America’s largest metal forming, fabricating, welding and finishing event. Don’t miss four days of the latest innovations, equipment demonstrations, peer-to-peer networking, top-notch education, and more. There’s no better time to talk shop with 1,200 top suppliers in one place and keep up with all the new developments so you won’t be left behind. Whether you’re a job shop owner, company executive, metal fabricator, production supervisor, plant manager, manufacturing engineer, welder, or purchaser, you can’t afford to miss this key industry event. FABTECH has the solutions you need to improve productivity and increase profits, plus the tools and resources to keep your business competitive. Start making your plans to attend today. Attend FABTECH 2011 as our guest. Register today for free show admission!

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FABTECH 2011
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TTP2011: Tools, Techniques, Processes forming high strength steel

2011-09-26T09:56:00.002-04:00

Recently attended the conference in Graz, Austria where many papers and presentation were made for furthering the use and processing of Advanced High Strength steels in Stamping.

source: AutoForm Engineering GmbH

One "hot" topic was the use of Hot Stamping (or press hardening) for ultra high strength steels. The technique utilizes alloys with Boron and relatively high carbon content that are heated to high temperatures then formed in dies. The dies act as a Quenching process that enables the martensitic phase to form in the material resulting in high strengths in materials that most likely could not be formed at room temperatures.

Source: AutoForm Engineering

At room temperature the material we discuss would be so strong as to be nearly impossible to form. However at elevated temperatures the material is more pliable (ductile) and will take on the desired shape more readily. The tool then acts as a "heat sink" and cools the material rapidly. Based on the rate of cooling you will form phase structures that leave the metal in a tempered martensitic state, or some combination of Austenite or Ferrite.

http://metallurgyfordummies.com/time-temperature-transformation-ttt-diagram/

source: APT

Still reviewing all the notes and proceedings before making more postings, but it was a very "lightening" experience and overall a worthy conference.

Aluminum body Panel stamping: Draw operation

2011-09-13T11:28:00.003-04:00

Blanks are fed to the first form, or "draw" operation

As we venture into the Draw operation (first form where-in a blank is given a majority of its part shape and depth) we will take a little side trip into metallurgy to discuss the oxidation of Aluminum. Yep, OXIDATION. At this moment some might take offense an complain, but *Die Expert (the self proclaimed is silent here) I thought that aluminum would not rust. And yes, you are right. but not rusting is not oxidizing. Aluminum is highly reactive with oxygen. The difference is that aluminum-oxide unlike ferrous oxide can form a non-permeable barrier. So the aluminum canoe that sits in a corrosive environment does not rust away like that old steel bucket because the oxidation stops after the first few micro layers of Aluminum-oxide forms.

The significance of this mention is not the "rusting" or ""oxidation" but the pervasive presence of Aluminum-Oxide on the surface of every aluminum blank you will ever process. Where else have we seen aluminum-oxide???? Asnwer: Sand paper.

Your aluminum blank? A super sized industrial form of this

Aluminum is highly abrasive in the stamping environment. Each time we try to form the aluminum blank we are dragging a sheet of giant sandpaper through the die. This is well known for most who stamp aluminum for a living, so before we ever enter the Draw operation we will have to process the blank through some sort of lubrication system to coat the blank with a friendly lubricant to ease the wear and tear that the aluminum blank will subject the dies to.

blank washer and lube application prior to loading via robot Source: Schuler group

Lubrication of the aluminum blank and proper cleaning is a consistent challenge in the stamping environment. especially for those undertaking the production of Major Body Panels. Here we should define and differentiate what might commonly be at the front end of many press-lines previously purposed for stamping steel body panels.

In some of the plants where I had worked we saw a variety of attempts at lubricating our steel and aluminum blanks, some successful and others not so much. Here are some of my completely subjective observations.

Too little lube? Adhesive wear of the aluminum oxide on the tool surfaces leads to galling and significant additional adhesive wear. On at least two of the products that I supported, this lead to a necessary SOP of cleaning out the die with "Scotch Brite" pads nearly every hour (they bought it by the roll). Abrasive wear of the die can result and the tool will lose its dimensional integrity. Tools for making outer skin parts were commonly chromed anyway at my plants so abrasive wear was kept very low, however chroming the die was expensive and meant there was very little chance for forming adjustments (the plant manager referred to chrome as die-maker repellent).
Is it a blank washer or a lubrication application: The blank washer is purpose built in most cases to apply a "detergent" solution that has some lubricating properties but its purpose is to clean the blank. When issues arise that seem like they can be solved with more lube. The washer was tuned (de-tuned) to leave more fluid on the part, however since the fluid was engineered to be a detergent it meant that it carried more dirt into the die. Washers are meant to use exit rollers to squeegee the blank "dry" leaving only enough film of lube to fill the surface texture of the sheet. Effective for many steels (hot dipped or electrogalvanized) but with aluminum and Galvannealed material a bit more secret sauce was desired to reduce adhesive and abrasive wear.
Too much lube? leaving excess wash on is not a fix to lube, and it came with the dirt issues. But other issues arise with excess lubrication (moisture) on the blank. Lubrication imprinting caused by pockets of lube trapped between the blank and the punch. For large surface area outer panels can look really bad. Lube is in-compressible so if you get a "bubble" of it trapped between the blank and the punch we got pretty bad surface defects. Aluminum is prone to this more so than steel as the incoming yield strength of aluminum is consistently lower than that of steel. Suction and poor venting lead to interesting behavior on the opening of the draw die. As a hydro-static seal forms between the punch and the blank. As the die opens the part could practically turn inside out if venting is not addressed. Excess venting to alleviate the inside-out parts did result in quality issues as the vent hole started to draw old lubricant and rust particles from the "core" of the die (the rust in this case was from the water based lube reacting with the cast-iron tools). Also, the old lube congealed over time and lead to "boogers" that would also get trapped under the blanks and lead to surface defects. Safety and handling soaking wet blanks was a major issue, during my stay at one plant two die makers suffered broken arms as they fell servicing draw dies that were dripping with lube. Also, production personnel has issues with saturated gloves after only 10-15 parts that they would have to deal with for the remainder of the production run (or until the next cycle-stop or "andon" interruption).
Lube compatibility with paint or steel production: not all lubes behave the same and cannot be assumed that there is a one-size fits all lube. So in order to run well, there was a fully dedicated line for only aluminum panels. (This also comes up later when we discuss scrap.)

and that was just Lube (still not fully into the draw application yet).....

I guess more to come later......

Aluminum stamping: Major Body Panels

2011-09-08T17:11:00.000-04:00

Following up on the request for information on Aluminum Stamping ins and outs from an SME member in South Africa I made a quick brain dump which I will now try to elaborate upon. To frame this discussion should start with a brief overview of the "stamping process".

From coil to part- a stamping process

To produce major body panels the stamping process commonly will take the coil of flat stock (for this discussion aluminum sheet most likely in the grade 6000 series for outer or 5000 series for inner panels). The coil will be cut into regular sized and shaped pieces we will call "BLANKS". Those blanks will be collected, stacked and brought to the stamping production line. An example of a stamping lines are shown below.

source: Spartanburg Steel Flickr site

source: Schuler press USA

The stack of blanks will then be "DESTACKED" and fed into the first forming or "DRAW" operation. It is at this point we can first start talking about the challenges in forming Aluminum sheet when you are already tooled up to run Steel.

Blanking and Destacking challenges:

Source: the fabricator.com

Aluminum is non-magnetic. This elementary fact raises issues when it comes to destacking. Commonly in the stamping plant they will use suction cups to lift the blanks from the stacks and load them into the press to prep for first forming. The stacks of blanks will be commonly 200-300 parts deep. To ensure that only one steel blank is picked up we commonly use what are referred to as "fanner magnets". These are electromagnets positioned at the edge of the stack of blanks. As the suction cups lift the top blanks, the "fanner magnets" assist in separating the individual sheets. This prevents the accidental loading of multiple blanks into the first forming operation. Without the benefit of fanner magnets alternative methods to break the surface tension between the blanks is needed.

source: magnetics.com

Air knive, Source: atlas pressroom automation

Air Knives as replacement for fanner magnets spread "DIRT" onto blanks. A workable solution to the "fanner magnets" is the use of powerful "air knives" which blow on the edge of the blank in an attempt to separate the blans. This proved problematic as any slivers, dirt, or debris that is on the edge of the blank would be blown across the blank. The blanks which are commonly shipped with an oily film on the surface of the blanks will invariably attract the dust, dirt, debris to its surface and carry the foreign material into the forming die. During the forming process any debris on the blank could lead to surface imperfections as the minute sliver of material is embedded into the sheet surface (top or bottom) and cause significant surface defects.

Aluminum sheet trims less cleanly than steel, so slivers are a consistent problem. It was near unavoidable that some slivers would be on the edge of every blank. Air knives and other part handling issues spread the slivers in a consistently random way onto the parts. It was very hard to predict where the potential surface problems could arise. As a result we had very high rate of inspection for these parts to segregate the parts that might require surface finishing from those that would not (very few).

So that is the problems that happen prior to forming. In following posts we can further explore the potential problems with Forming, Trimming, Piercing, Flanging, and Hemming.

SME Stamping and Dies: Sept Teleconference agenda?

2011-09-06T17:29:00.001-04:00

what's on the agenda for the September Teleconference??

Up to you.... here are some possible ideas:

Aluminum Body Panel stamping (from forum)
FABTECH and upcoming trade events discussion
WEBINARS (December scheduled, other dates available)
How do I get active in the SME Tech Communities?

If you think we should discuss something different contact us by adding a comment here or using the widget below to leave us a Voice Message (the widget call you at your phone).

Join us during the teleconference which will be held on Wednesday Sept 14 @ 2:00 PM Eastern Time (USA)

Call toll-free ~~1.877.688.4493~~

	1-877-669-3239 (better number)

or 1.408.600.3600 (U.S. and Canada)

use meeting pass code 23140035

Aluminum Stamping: follow up to a Forum Question

2011-09-06T16:50:00.003-04:00

Recently on the SME Stamping and Dies forum a post with request for information about the "Ins and outs" of stamping Major Body Panels in aluminum came up. Which stirred some fond (and not so fond) memories of this particular Self-Proclaimed-Die-Expert.

source: http://electric-vehicles-cars-bikes.blogspot.com

Here is a brain dump of some potential topics:

Production handling (non-magnetic, surface damage, lubrication, mass {lack of}, segregation of scrap)
forming (reduction from steel, friction and lube, wear {abrasive}, Springback, Surface Quality, thinning limits, engineering, die design)
Trimming (slivers, burrs, surface damage, breakage, clearance, scrap drop, slug shedding)
Engineering (material grades, designations, specification, mechanical properties, design for forming and manufacturability, Tooling coatings and substrates)
Cost: sheet/coil, Scrap reclaim, new processes, etc

I guess covering the Ins-and-outs could become a full time job if one wanted to try. I at this time will not attempt it. Maybe some of the topics will make good discussions for the Stamping and Dies Technical Group of SME or the Metal Forming Simulation Tech Group.

SME Stamping and Dies TECH GRP: August Agenda

2011-08-03T07:16:00.002-04:00

For the August conference call I propose the following agenda.

The stamping and dies technical group is a virtual community of SME members who all share an affinity to the Stamping and Die industry. Under the umbrella of the Forming and Fabricating Technical Community, it seeks to allow SME members an opportunity to Meet, Know, Grow with other like minded professionals. It is the goal of this group to meet monthly to further technical knowledge in stamping and dies.

We meet every second Wednesday of the month for a conference call. All SME members who are in some way related to the use of Dies for Stamping Sheet Metal should join our call. We offer the chance for any of our members to be active in directing the group, and any SME member can use the Webinar platform we offer to promote their technology or company.

Eric will most likely not be on the call live (taking the kids to camp) but will provide some input via proxy for the meeting, as could any active member. We have to get good at proxy and asynchronous activity otherwise the virtual group will be stuck as a phone only group.

Call time and date:

Wednesday August 10th, 2011
2:00 PM Eastern Time
Call-in numbers: 1-877-669-3239 (free) or 1-408-600-3600 (toll)
Access (meeting number) 23140035

Roll call and greetings (0:05)
trending topics in dies and stamping (0:15)
finalize webinar schedule for 2011 (0:15)
discussion of members access website proposal (0:20)
tabled items for next month (or asynchronous feedback) (0:05)

For more information leave a comment here, or contact Eric Kam (the self proclaimed die expert) via this blog or LinkedIn or SME forums.

Use the link below to leave a voice message for the leaders of the SME stamping and dies technical group.

Die Turnover operation: Flying the die open

2011-07-18T04:07:00.002-04:00

A recent inquiry from an SME forum had me scouring the net to find video of the operation of "flying open a die". Turns out that while it was ubiquitous in all the die rooms and press rooms I have worked at there was little to no video footage of it happening; nor much in the way of procedural documentation.

A post to the LinkedIn Stamping and Dies community yielded paydirt. After only one month. so without further delay here is the video. Thanks to the folks at F&P America for the courtesy of the video.

With this video of course there is no warranty or promises. Will not be held responsible if you try to replicate and can't manage it. Bear in mind that in the video they are using appropriate die handling and their tools have been designed with this operation in mind.

pick up top half of die using syncro'd bay cranes (4 pick-up points)
with upper clear of the lower lower one side of the die until upper is fully held by one side
un-hook the slacked lines and re-attach after rotating the die 180 degrees
Lift the slack side (or lower the other crane line)
put it down when safely horizontal again

What is the value in you provide in your job?

2011-07-16T20:50:00.000-04:00

Back in the day, I used to wake up at 4:00 AM to be at the plant by 5:00 AM to prep for shift changeover as 3rd makes way for 1st in a real life honest to goodness stamping plant. In those days as a technical consultant, our job was to assist the plant in realizing their goal -- filling parts racks.

We invariably would get into highly theoretical spats (two diemakers, one metallurgist, and me made for just a little bit of over analysis), at which point Lance would remind us; "Guys, don't let perfect get in the way of better." I guess that is why he is the Plant manager now and we are all still dieguys slugging it out in the consultants pool.

Yes we have all been striving to make "science out of the art of stamping", but ultimately the idea is to stamp out sheet metal parts and in many cases the parts and dies don't know that the simulation was or was not done. What is true is that the simulation helped solve some part of the problem, but solving the simulation was not the goal; it was a means to the end.

Now i see the same thing happen with the die processing tool we have been trying to bring to market. We show it to many die process planners who look at it and ask, "Can it make reports that look just like ours?" and I need to ask these same people, is your job planning the process or making reports. And not surprisingly they say that planning processes are their jobs, but their insistence on having just the right reports shows me that they have lost sight of the value the bring to the process, their expertise in process planning (not in report writing). Now just have to get them back on track.

Planning a stamping process is more than making a sketch of the part with some nice little line depicting the trim stages. It should be a critical analysis of the capabilities of the dies and presslines to contain the process that is being described. This requires very highly developed sense of space and 3D visualization skills. Often this planning had been done with little more than a sketch. From which the gurus of processing would be able to define appropriate die tips, trimming segmentation, and process order.

The work was the thinking, the report was a document to capture their ideas. But these days more and more people are focused on making the reports, without the critical thinking. If the report pictures are pleasing it does not matter if a person every looked at the part. That seems wrong. What effort makes process planning better? Prettier pictures or a tool that enable die process planners to better visualize and capture their decisions (which might actually allow for skipping the paper)?

Think about it.

Press Maintanence and Part quality

2011-06-15T13:30:00.000-04:00

Thanks to Dean Phillips of Link Systems for presenting today's webinar on Press Maintenance and Effect on part quality, for the SME (Society of Manufacturing Engineers). A lot of what we discuss seems common sense, but amazingly as I travel about the industry we often see that what is common sense to one, is on-common sense to others. As our industry gets more and more diluted and as we retire more of the knowledge while at the same time changing the rules of the game.

It is always refreshing to be able to spend some time discussing the basics with others. Especially, when we find that what we thought was basic was new to another, and even more beneficial when somebody is able to easily communicate the knowledge we lacked as the basics.

Do you have some BASIC knowledge that would be beneficial to others? Then share that information with your fellow professionals. Raise the esteem of you company and yourself within your professional niche. Share what your know.

Meet Know Grow -- SME

Metal Forming Simulation, webinar in July

2011-05-09T14:49:00.000-04:00

This July one of my colleagues from the US office will present a webinar on the topic:

Trim Line Development in the 21st Century
Date: July 18th 1:00 PM Eastern Time (US)
to be followed by a teleconference of the Metal Forming Simulation Technical Group of SME.

Things you will learn:

Traditional trim line prediction
In-press development and finalization
Trim line development and validation using simulation software

Benefits:

Recognize limitations of conventional trim development
Identify the potential gains and risks in applying software based trim development

Who Should Attend:

Die designers, die technicians and die engineers
Material utilization groups
Process planners and estimators

Presenter:

Mark Hineline, AutoForm Engineering USA, Inc.

Stamping and Dies Webinar, sponsored by SME

2011-05-09T14:40:00.002-04:00

Webinar Title: Impact of Press Maintenance on Stamping Part Quality

June 15th, 1:00 PM EDT (US eastern time zone)

Followed immediately by the SME Stamping and Dies Techgroup conference call. This is different than our normal meeting time to allow for the SME Annual meeting
Registration

This Webinar is being presented by the Forming and Fabricating Technical Community, Stamping and Dies Tech Group. The presentation will detail how items on a press will impact performance and part quality. How things like slide parallelism, deflection and drive clearances impact tooling and why this is important in the context of part quality and longevity of tool life.

What you will learn:

Press Inspection Items
How Press Maintenance Impacts Part Quality and Die Life
Press Metrics and OEE
Pressroom Tools for improving performance

How this knowledge benefits you:

Finding the causes of tool damage, wear and preventing the outcome – loss of money
Finding the root causes of poor part quality
Reducing Downtime
Improving Efficiency

Who should attend?

Tool and Die
Maintenance Managers and Maint. Technicians
Plant Manager
Engineers
Lean / Six Sigma Champions
Team Leaders

This is not focused only on maintenance but focused on the entire process and preventing pitfalls that impact your part quality, damage presses and reduce OEE. We will detail how tools like tonnage monitors, die protection and communication networks are vital to monitor and track part quality, OEE and maintenance of tooling and presses.

New technology to reduce scrap- Programmable dies, new materials and lubrication technology is now available to reduce scrap and tooling wear.

About The Speaker:

Dean Phillips – LINK Systems Safety and Automation Controls

Dean Phillips is an advocate and advisor for the Metalforming and fabricating community. He is currently focusing on safety, press controls, and automation processing. With over 20 years of experience in manufacturing he has visited most leading metal manufacturing plants across North America. He has also toured European, Asian and Middle Eastern manufacturing plants.

Dean has worked in many positions for leading press builders and fabrication companies.

simulation and reality: Bridging the GAP

2011-05-03T11:11:00.000-04:00

Panel safe in simulation (Wrinkles reported within tolerance)

As a simulation professional I often hear complaints that the "simulation has not matched reality, again." However my response to them is that reality failed to match simulation. There is a subtle difference in those two statements and hopefully something that we can all take-away with us to improve our own organizations ability to use simulation.

Real Panel with issue (near splitting in RED, Wrinkles purple)

First people will blame the simulation often when during tryout the results of the tools or process do not match the results predicted in the simulations. Here is list of questions we need to have answered before we can try to assess "blame" or "fault":

Has the die achieve As-Engineered state?
Are we using the same blank?
Are our materials within expected ranges?
Is the die properly spotted and set-up?
Were the inputs of the simulation within as-planned spec?

Within these first 5 questions it is usually easy to put our finger on a culprit input. Blank shape in the simulation was different, or location was different. Often basic die build issues like proper finishing of die radii or other geometric issues can be identified (die radii are not TRUE, or die is poorly spotted).

But if we have worked our may through the list of usual suspects what comes next? If we find that die is to spec, and materials are within expected ranges, then what? I have heard may people espouse matching draw-in or other such techniques for "tuning" in the die, but exactly how do we get there? What "handles" to we pull in the die to make the processes match?

Colleagues of mine have been promoting an idea that we call Tryout Maps. A tryout map is a method by which we can use stochastic simulation results to interpret the causal relationships between various inputs and results for given stamping dies.

Using hundreds of simulations that have been run with different combinations of inputs (within the range of variation established by the user) it is possible to see how the various inputs in the areas of interest respond to changes in the inputs. It the figure above the red circles indicate that changes to db1 and db5 are directly linked to failure potential in Zone 1 and Zone 2. The red circle indicates that increase in db value increases the output response (which in this case is bad). The size of the circle shows the relative sensitivity to those influences.

Zone 3 shows wrinkling tendencies and how the potential inputs influence that possible outcome. db3 and db5 show influence on the potential to wrinkle in those areas (in this case any decrease in db value results in an increase in output response; loosening the beads 3 and 5 will increase the wrinkling tendency). This tryout map clearly shows the user that any adjustment to the bead to decrease the splitting potential will increase the wrinkles in the adjacent areas, and vice versa. This is likely common knowledge for most stamping professionals, they will be able to imagine this outcome just by looking at the location of the issues and the beads.

What is not intuitively obvious, is what to do in this case to resolve this yo-yo effect. but with the tryout map we can see that it is possible to affect change to the wrinkling potential by making an adjustment to the blank location in the positive x-direction. Shifting the blank has a high influence to the wrinkling potential in ZONE 3 without inducing splitting changes in zones 1 and 2.

This type of information at the tryout source can be attained almost instantaneously at the tryout source, since we are not running if-then simulations or trial and error in the die, but merely looking up from a catalog of already computed results.

Metal Spec: Redux

2011-04-04T20:21:00.000-04:00

Because the topic never seems to get old, we can again revisit the topic of material specifications. It is a topic that has been covered here and in other places few times before:

http://kam-stampingguru.blogspot.com/2010/02/stamping-materials-what-we-dont-know.html

http://kam-stampingguru.blogspot.com/2010/02/stamping-materials-we-get-different.html

http://kam-stampingguru.blogspot.com/2009/11/sheet-metal-specs-and-standards.html

http://kam-stampingguru.blogspot.com/2010/08/springback-101-what-is-it-re-post.html

In each different post we reference the material strength, N-value, R-value, and Tensile strength bu did not discuss where those number come from. So below we "borrow" a video from our friends at Thyssen Labs in the "D".

With this video as background we should now consider where and what you rely upon to understand the materials that you use in trying to make your living.

Are you relying on the "grade" spec that is the "worst case" allowable material for the product performance? That material might not be what your process needs to work, nor do the people who order the material care (or know any better)
Do you define "in spec" as good enough? who wrote the spec? Product engineers and purchasing people have VERY different ideas about what YOU need to make those parts?\
When you have a good day, do you know where that material was in the range from Worst to Best that you can expect? or do you only test the materials that fail?
When you have a bad day, does the material always "meet spec"? do you know what that means?
The people who engineered the process that you are trying to support, matched the material to the process. Have you altered the process? That might make the good material not work any more.

Material is only one part of the equation. The stamping system is made up of the following pieces:

Tool
material
press
process

A simple analogy is to think of the tool as the Lens of a camera, The material is the film (yes old outdated anaolgy), the press is the camera (which can use different lenses), and the process is the settings used for the combined system. You can't take good pictures without somehow getting all the parts working together.

When a bad picture comes out, we don't immediately blame the camera, or the lens, or the film but we consider how the operator set all those things to work together. But when we stamp bad parts, we nearly always blame the steel.

Predicting Edge Cracking potential in sheet metal parts

2011-03-28T13:24:00.000-04:00

In a recent discussion with an Industry-Proclaimed expert in stamping and dies we came up on the topic of prediction of edge cracks in flanges for new sheet metal parts. Currently, there is no Iron-Clad method for people to use when evaluating the edge cracking potential in new sheet metal parts.

This is because edge cracking potential in actual parts will vary greatly with the edge condition of the part as well as the amount of deformation that the flange instills into the edge itself. However, there are some helpful indicators to the potential for part geometry to cause an edge crack.

edge cracking is typical forming issue for "stretch" flanges

Edge cracking is simply a failure in the sheet metal (split) caused by the formation of a stretch flange. Stretch flanges are those flanges that from initial shape to finished shape cause the free edge of the metal to stretch. We recognize stretch flanges in the following situation; extruded holes, flanges in wheel arch of car, cowl hems in the hood and deck-lid of car, or any flange where the plan view radius of the flange has its center outside the bend (concave).

the trim edge of the flange in initial orientation

Typical to these types of flanges the sheet metal will be trimmed to a curved edge prior to the flanging operation. As the trimmed metal is flanged downward the material on the free edge of the flange has to stretch from the original length it has during the trimming operation to take on the new edge length (dictated by the plan view radius of the finished flange).

The free edge of the flange stretches as the flange is formed

The amount of stretching in the flange (or engineering strain, e) is calculated by estimating the difference in the edge length before and after the flanging, and then dividing by the original edge length. The difference in arc length of the trim edge initial and the trim edge final can be estimated using the Plan view radii of the initial trim line and the plan view of the flange. As shown in the calculation below, you can then assume that the plan view radius of the initial trim is equivalent to the final plan view radius minus the intended length of the flange.

relating the part geometry to stretching required to form

Once the Strain (stretching) in the edge of the flange is estimated. Then comes the issue of determining what amount of stretching is likely to result in failure. One very simplistic prediction is to compare the calculated stretch to the total elongation defined for the material specification. If the strain calculated (e) is greater than the total elongation then it is certain that the flange will experience edge cracks (unless process modifications are made*).

However, there are many stretch flanges that will exhibit edge cracking while still having stretch amounts below total elongation. In fact, failure is likely for for strains that are well below the total elongation. A second diagnostic number that could be used is to relate the strain calculated to the FLD for the sheet metal specified.

To estimate the location in the FLD for the edge condition, one can use the number calculated for the edge stretch (e) as the major strain in the FLD. The minor strain can be predicted as the intercept of the major strain value with the Uniaxial Tension Curve (UTC) in the FLD. It can be safely assumed the the stretch flange is a mode of deformation coinciding with the UTC. If this intersection lies above the marginal line, it can be concluded that with preforming stresses, and possible edge imperfection that the edge stretching will result in failure.

However, falling below that line is still not an assurance of safety. It has been shown that with edge stretching, that BURR Height can greatly reduce the edge stretching potential in many case by 50-70%. but predictive modeling such as the method discussed here can do little to predict the end sheet metal condition regarding burr severity.

In conclusion:

using the part sketches or drawings calculate the stretch potential in the flange edge
e = (l)/(Rf-l) greater than total elongation (design different flange or define alternative process*)
e = (l)/(Rf-l) and intercept with UTS is above the marginal zone in FLD (change part or process*)
e = (l)/(Rf-l) and intercept is below FLD by 50% might be safe with some burr conditions

* (footnote) the techniques for reducing the severity of potential edge cracking through alternative design and process is something for another posting

Transfer paths, curves, and die design

2011-03-07T02:25:00.002-05:00

I remember not too long ago--after all I haven't been in industry THAT long have I--going to patter shows to review the die designs for suitability for transfer automation. Looking for die interference, clashes, and other issues that might make production in transfer presses very difficult, expensive, and maybe impossible. And how did we check this? Designers from the supplier would arrive with cardboard templates of the transfer path and we would use string to trace the path between the Styrofoam patterns prior to casting.

REALLY!!
NO Lie, that is how it was done.

This week I will get to participate in a webinar outlining how during CAD design we can directly evaluate our die designs in a virtual press for transfer interference, when it is still possible to influence cost effective change.

3ddiedesign.com offers transfer simulations to evaluate tooling design for fit to press automation

Presented by the SME Forming and Fabricating Community and their Stamping and Die Technical Group the webinar will review two case studies where CAD tools allowed for design modification and optimization that ensured successful and efficient stamping production.

Progressive Dies: Engineering and Design

2011-02-21T05:28:00.000-05:00

The Design and Engineering of progressive dies and the parts and processes completed in those tools recently cam up in a LinkedIn discussion. Listed in the link were a series of tools out there that can allow one to Design Progressive Strip Layouts, and subsequent tooling. However, this always makes me wonder: "What is the difference between Engineering and Design".

Die Design is the creation of the tools, tooling surfaces, tooling solids, the mechanics of the tool itself.
Die Engineering is the development and evaluation of the process that the tool is designed to achieve.

This brings to mind the fact that while there are many tools that allow one to design any number of probable strip layouts for a given progressive part, that we still have to evaluate (in and engineering fashion) whether or not the sheet metal agrees with us. After all, designing a strip layout using unfolding techniques is still a far cry from finding out that the sheet metal will actually behave in the manner which we designed into the strip.

A very common mistake is to assume that because we have highly detailed designs that the behavior of the sheet metal will follow those assumptions. Even the best digital design tools while aiming to aid the designer with unfolding of the part and predictions of intermediate geometry, require some form a validation.

It is a great form of hubris and ego that assumes that merely because we draw it one way on the computer that the sheet metal will cooperate. So which ever design tool that the person, who posted the original question, chooses he should still require an ENGINEERING tool like AutoForm to evaluate the effectiveness of the prog strip to achieve the designed layout.

Trim line and developed blank optimization
Deformation of carrier and web during forming
thinning and compression in the part
Deformation of pilot hole locations during forming
Springback in the part (and web in between operations affecting location)

Transfer and tandem lines: what is the difference?

2011-02-14T04:52:00.000-05:00

Following up the last post on progressive dies we can further define what might be meant by the terms transfer dies and tandem lines.

One thing to note is that transfer dies is nearly a misnomer: the dies themselves do not possess any attributes that limit their function to that of transfer or tandem operations. Transfer and tandem more appropriately refer to the pressline.

The tandem pressline refers to any line of individual presses which may be used in conjunction with a set of dies that completes the processing of a part or parts from blank to finished stamping. This is as opposed to individual presses that are used separately to complete only limited portions of the production of a part (stand alone stamping is hardly ever done anymore). Commonly with tandem lines automation will be placed in between the separate presses to handle the movement of the parts from operation to operation.

Transfer lines are modern presses where a single press can hold more than one tool allowing for the entire die process to be complete while the part remains in the single press. Most commonly these types of presses contain all the automation needed.

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