Rooster's Revenge

A good friend of mine emailed the other day. People think I am driven and passionate about the die industry. I don’t hold a candle to Erkan. He reminds me of me 20 years ago.

I am giving him some help offline, but perhaps you can lend him some of your expertise as well. Here is his note:

Hello Tim,

I follow your web-site regularly. I am doing my master of science degree at mechanical engineering department here in Bursa-Turkey.

I passed all exams and finally started to doing my thesis. my thesis is “To formability of low-metal alloys of automobiles body sheet-metal parts”.

I am working with aluminum and magnesium alloys. Do you have any ideas to give me about these topics ? Where are we in these topics at now as die industry ?

Thanks,

Erkan Aybaraz

Please click here to email Erkan directly. You can also leave a comment on this post or contact me through the contact page.

Congratulations to Erkan, by the way, on nearing the completion of his MS degree. That is a tough program … you make me proud.

I remember telling the GM Die Standards Task Force that the die standards should be published as a searchable web-based tool instead of the traditional static paper document in a three ring binder.

That was 1992.

For the past 15 years, it has been a static PDF document.

Hoo-ha.

Why not publish die standards using WordPress blog technology?

I have spent my entire career solving business problems by using technologies that were not intended for a particular purpose or use.

Most folks call that “out of the box” thinking.

I call it “find a way or make one” doing.

Using WordPress blog technology is no different in this case. Let me explain.

Die standards should have three properties:

1. Searchable for ease of use;
2. Web-based for global accessibility;
3. Fast for publishing and commenting.

WordPress fits the bill. Even though this technology is meant for blogging and not a procedural document like die standards, it simply works. Perfectly.

Imagine the categories as topics, such as draw dies, casting construction, and pressure systems.

Each post in each category would be the traditional “section”, such as gas springs, nitrogen manifolds, etc.

I would tag each post with relevant uses to make searches easier and relevant.

Got a trim die with cams in a transfer press? Search on trim, cam, transfer and BAM! All relevant die standards would appear in one list. All the standards you need to get the job done.

How about a question on the intent of a standard while sitting in a die shop in Taiwan or Korea? Simply post a comment from your Apple iPhone. The die standards folks would get an automated email with the comment that they can post a reply to or contact the person with the question directly.

How sweet is that?

The coolest thing about my idea? Go beyond static images with videos, animation, and audio files is possible with WordPress.

Hell, you could even link to engineering files or additional information at suppliers’ websites.

Speaking of suppliers. How many times do you have to search the web for a catalog item? No more with my idea here.

I would use the blogroll area to link to all approved supplier websites / catalogs.

The best part of all this? You don’t have to be a publishing expert to use WordPress. If you can type an email, you can blog.

Ok. Maybe that is the best part for the technical folks. The best part for the management folks?

Saving a boatload of cash in publishing and printing costs to maintain die standards.

Very soon, I plan to setup a demo of what is possible. I have registered the domain diestandards.com and will update you when I get a prototype up and running (busy running around the country these days).

There has been a surge of hiring activity lately in the die and stamping industry.

Most of it, from what I see, is attrition-related and not from growth. A turnaround is coming, but it is not here yet.

DieGuy.com reader Karen Bradley sent me a note this weekend:

Hi Tim,

I am looking for a Tool Room Manager (metal forming/stamping technical expertise) in York, PA for a great privately owned company. If you know of anyone who may have interest, I would appreciate any references.

- Karen (Rohrbaugh) Bradley

The search is for a privately-held manufacturing company in York, PA with great potential. They have been in business since 1941 and are already positioned in the top 5% of their industry.

If you are a strong leader in the Tool Room area who can manage the function and set the overall business plan to grow this group even more, then this may be the opportunity for you.

For more information, please click here to email Karen or contact me through the contact page.

It took me about six months after the Speedraft CTO meltdown to figure out what to do with my professional life.

I got a call from a friend in the business that led to two interviews. Out of the blue, I get contacted through this blog on a third cool opportunity.

In the matter of a week, I go from completely lost to overwhelmed.

It was a tough decision to walk away from Speedraft. Now, I had a tough choice on where to live and who to work for. I mean, how do you choose from three great companies in three cool places to live and work?

For a variety of personal and professional reasons, I chose a great opportunity at Tower Automotive, soon to be Tower International after their IPO.

Looking ahead, I feel my best work is yet to come. There is much to do on a die standards front, and with improving the efficiency of transfer presses.

In general, I feel transfer presses are under-used because they are misunderstood. This partly goes hand-in-hand with die standards simply because the die sets are designed wrong for transfer.

I am up for the challenges and opportunities ahead.

And, I am glad to be back in Detroit full-time in-time for Bob Seger’s final tour.

I have been interviewing for die engineer positions lately. For those that are familiar with Speedraft, I will blog on that experience soon.

During this interview process, I have been forced to take a look back over my career.

Looking back, I was in the right place at the right time. For the most part.

Starting off in the manual world and engineering dies for 100+ hours a week, I was in the unique position of gaining alot of experience fast.

In today’s world, it would take 15 years to accomplish what we were doing in just one.

I was asked what my most significant contribution to the die world was. It would have to be writing die standards from a clean sheet.

Then came the question of what I am most proud of.

That is the easy question: training die engineering apprentices.

The gratification of having a small part in the development of some of the best die engineers in the world is something that most will never experience. And I will never forget.

I am proud to be part of the stamping business. Time may have robbed me of some speed, but I feel I am still at the top of my game.

The other day, I blogged about how to heel internally to compensate for unbalanced thrust.

A similar situation arises with presses that have rams that suffer from unparallelism due to worn gibs.

Dies end up getting designed and built with heeling provisions in a feeble attempt to compensate for worn press gibs.

This falls into my “bad intentions” category of rational thinking.

If the press is broke, then fix the press.

Before my critics give me a speech on it costs too much or takes too much time, consider the following analogy:

You make a living running top fuel dragsters.

The car reaches speeds of over 300 miles per hour in a quarter mile.

One day, the brakes wear out and the parachute needs to be repacked.

The crew chief wants to replace the brake pads and repack the chute.

A decision maker says it will cost too much.

The solution? Cut a hole in the floor and have the driver stop the dragster Fred  Flintstone style.

During the last 50 feet of track, of course.

Sound stupid?

This is no different than the press / die scenario.

The press gibs are measured in meters. Die wear plates are measured in millimeters.

Press force is measured in tons. Die force is measured in kiloNewtons.

Ram travel is measured in meters. Die travel is measured in millimeters.

No matter how you look at it, the press wins everytime.

There is no way that the relatively small engagement of die heel plates will overcome and correct parallelism of a larger press ram traveling at production velocities near the end of its downward stroke.

What to do?

Fix the damn press.

For those that insist on being the Fred Flintstone, do the following:

1. Do NOT attach the upper shoe to the ram.
2. Engage heel plates on the die 100 mm before the guide pins.
3. Install gas springs for counterbalance before guide pin engagement.

Be sure the gas springs have enough travel to open the die far enough to load and unload the stamping without interference.

Or, forget your bad intentions and just fix the press.

The debate on how to counteract unbalanced thrust lives on in the stamping industry.

I have seen it first hand in several markets. Automotive. Appliance. Medical device. The list goes on.

Here is a note sent to me by one of my DieGuy.com readers through the contact page of this site:

Hi Tim,

Really enjoy reading up on your blog & your die knowledge. I have a question for you, that may also lend itself to a blog topic.

Is there any hard and fast “rule” regarding thrust blocks or supplemental guidance in a die?

I understand the point is to counteract unbalanced thrust, etc. but I was thinking more specifically when to use a 6-post die set versus vee-style thrust blocks versus rectangular thrust blocks, etc.

What is the best style? How do we quantify this?

And if needed, the best places to locate thrust blocks and/or extra guidance members if you cannot get them right next to the thrust source.

This topic has always been a source of debate among many of us! It’d be great if you could clarify things! Thanks and keep up the great work!

A fan,
Greg Grigutis

Tool Design/CNC
Spalding & Day Tool & Die
Louisville, KY

This is a great question. So, let’s breakdown Greg’s excellent question into these five critical characteristics:

Rule

The rule on if and when to use some heeling device to counteract unbalanced thrust from cutting or forming is this:

If the lateral force exceeds the single shear load performance rating of the dowel pins that locate the cutting or forming device, then that device must be keyed, pocketed, or heeled to absorb the unbalanced thrust.

Type

There are two choices for heeling steels or components that are subjected to unbalanced thrust: Heel externally on the die set or heel internally near the source of lateral force.

Conventionally, most die engineers locate the heels externally. This is just wrong for one simple reason: these heels are too far away from the source of lateral force to be effective.

The die set guide pins will end up taking all the force. If the force is high enough, the guide pins will deflect and bend.

Style

What style of internal heels is best? The one that works for the unique requirements and constraints of your die design.

The generally accepted styles are machined pockets, solid keys, heel blocks, and wear plates.

That said, machined pockets and solid keys are the simplest method (no running clearance fitting) but are only effective if the cutting or flanging component has a base-to-height ratio of at least 1.5-to-1.

Some style of thrust block, like heels or wear plates, is best if the base-to-height ratio is less than 1.5-to-1. In this case, the engagement of the thrust block must be at the same elevation as the cutting or flanging work.

No matter which method you end up with, just make sure that the heeling device is close AND perpendicular to the lateral force vector.

This is why I am not big on vee-blocks. For vee-blocks to be effective, there must be two force vectors, each at 45-degrees from normal, such that each face of the vee is perpendicular to the force vector.

Assuming normal running clearances, using vee-blocks in a typical unbalanced thrust situation means that the face of the vee is 45-degrees to the lateral force vector. You effectively have more clearance before the heels take effect.

I prefer commercial wear plates if they fit or homemade aluminum bronze heel blocks if keys or machined pockets won’t do the trick.

Quantify

You already know how to quantify lateral force for cutting and flanging. The question now is how to quantify the internal heel so it is not too small.

This calculation needed here needs to find the adequate surface area of the heeling device, working within the compressive strength of that heeling device.

A simple equation for this is:

• Ah = (1 / CS) • Fut

where:

• Ah = Area of heeling device (mm²)
• CS = Compressive strength of heel material (kN / mm²)
• Fut = Force of unbalanced thrust (kN)

Note that most materials have compressive strength rated as Newtons per square millimeters. I convert this to kiloNewtons to work with the other die equations.

Location

Always use internal heeling devices as close to the source of lateral force as possible. Again, this is both in the plan view and in the elevation.

Don’t forget to keep the heel face (or machined pocket or solid key) as perpendicular to the lateral force vector as possible for maximum effectiveness.

Greg – I hope this clarifies things. My goal here was to be clear, concise, and precise. Let me know if we need to discuss any of this topic further.

A while back, I blogged on how to quantify unbalanced thrust in cutting dies. Today, I would like to share the same for flanging dies.

Forces in a flanging die are equal and opposite. So what happens when flanging occurs on one side of a cutting component? Unbalanced thrust.

The issue with unbalanced thrust is should the flanging component be heeled or keyed to counteract the lateral force.

The first step to this decision is to quantify the magnitude of unbalanced thrust. The equation for unbalanced thrust in a flanging die is:

• Fut = Stan • (Fb / t)

where:

• Fut = Force of unbalanced thrust (kN)
• Fb = Force of bending (kN)
• t = Material thickness (mm)
• Stan = Span between upper and lower flange steel entry radii tangents (mm)

For example, a flange die with a span between upper and lower flange steel entry radii tangents of 12 mm (in other words, the linear distance of unsupported material when the upper and lower steels are at initial contact), bending force of 75 kN with a stamping that is 1.2 mm thick has a lateral force or unbalanced thrust of:

• Fut = Stan • (Fb / t)
• Fut =12 • (75 / 1.2)
• Fut =12 • 62.5
• Fut = 750 kN

This means that 750 kN of lateral force is acting on the flanging component. Lateral force, or unbalanced thrust is perpendicular to the flanging vector and not necessarily horizontal.

I was recently approached by an automotive OEM regarding the selection and purchase of formability simulation and analysis software for metal stampings.

Purchasing this type of software is much different than, say, solid modeling software for one simple reason: formability software is like rocket science.

Die shops and stampers gamble hundreds of millions of dollars, and in some cases, billions of dollars annually on the computational results of formability software. This is not true of engineering or office software.

How would I pick “the one”?

My top five questions for the software company are:

1. Results: How realistic and reliable are the results?
2. Friendly: How user-friendly is the software for the average die guy without a PhD?
3. Support: Do you have a die-savvy technical support staff?
4. Training: Do you have confidence-based training for new users?
5. Community: Do you have a user-group community?

If the results are realistic and reliable from a user-friendly package that does not require a PhD in Finite Element Analysis or Rocket Science to use, and excellent technical support, training, and user-groups are all there, then it all boils down to price.

I installed a plugin today called Twitter Tools.

It allows you to get a tweet everytime I create a new post.

Follow me on twitter at #thedieguy.