Mold Cloning—Isn’t This Illegal?

As tempting as it is, cloning is seldom a good idea unless the DNA has come from a proven, reliable performer in the press that also has been well thought out from behind the bench.


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The tooling engineer walked up to an old mold on the floor and blankly stared at it. He then rested his foot on it hoping the physical connection would somehow help recover faded memories of issues past concerning design and function. Although the images didn’t materialize, he did feel the heat of a dozen or so toolmakers staring at him, so he waved us over for a conference.

It seemed several of our company’s products were gaining popularity and the increased sales would require adding a couple of molds to a product line to handle the volume. His mission was to investigate any issues and best determine what, if any, changes should be made to the existing mold design. His other option, and usually the popular one, was to just clone this thing and be done with it.


Mold Cloning

Mold cloning is simply building the exact same mold over and over. It is not uncommon for companies, in an effort to increase volume, to acquire a backup or simply replace an old mold to partake in cloning. And since the communication chasm from a designer’s computer to a press or mold repair bench is typically Grand Canyon scale, not only is the mold replicated, but so are any problems inherent with the original design or methods of fabrication.
Here is a list of common reasons used to justify cloning:

No accurate data is available.
Accurate information concerning how a mold has performed (unscheduled stops, mold and part defects) and required maintenance (type of corrective actions necessary and tooling costs) is seldom available. Typical industry work order systems depend upon random, handwritten or typed journal entries that are incomplete, inaccurate or illegible. Few tooling engineers are willing to make changes to a seemingly adequate mold design based on these scribbles, fading memories or shop floor hearsay.

It’s easy.
Cloning is an easy form of mold engineering. Just send your vendor the prints and have their team make another one just like it—and they won’t forget your doughnuts in the morning.

It’s safer.
In a competitive engineering department, boldly creating a new lemon through bad decisions concerning fit, function and finish complicates the corporate climb more than replicating outdated technology, materials or design flaws from old molds. This is especially true if the new lemon turns out so bad it won’t run at all without first correcting serious, expensive problems. “If it ain’t broke, don’t fix it” is a popular mantra for less-audacious design engineers.

Speed and cost.
Obviously there won’t be any time spent investigating new plating options, steels, existing shut-offs, alignment features or tolerances. New technology? No time—just build it.

Fewer inventory hassles.
Some companies that have yet to establish an organized, functional tool crib for storing mold replacement components don’t want the hassle of storing or tracking tooling that will only fit the new, improved mold. It is much simpler and there’s less chance of a mix-up if one keeps tooling universal between all like mold frames.

It Doesn’t Always Work
As tempting as it is, cloning is seldom a good idea unless the DNA has come from a proven, reliable performer in the press that also has been well thought out from behind the bench. Most toolmakers will tell you they have never worked on a mold that could not be improved in some way or another, especially from the maintenance standpoint. Simple changes can save thousands of dollars over time in reduced labor hours and they make molds easier and safer to work on. With all of the advancements in mold design today, you still can’t beat hindsight when it comes to disassembly, cleaning, repairing and reassembling mold components and plates.

So we huddled up and in less time than it took for all of us to get our own foot up on the mold there was quite a discussion going on concerning the “junk factor” (problems with running and maintaining a tool) of this mold. It is common to have a range of opinions concerning the “junk factor” of any one mold because varying styles of hands-on work at a bench have a tendency to bias a repair technician through tooling bites, cuts, pinches, crashes or increased anxiety levels with awkward procedures.

These painful maintenance characteristics, although quite annoying, may or may not be the real high-cost roadblocks to producing quality parts on time. Data is needed to quantify. Many things, including hectic reactive shop cultures, can confuse the real issues for it becomes necessary over the years, when working in full firefighting mode, to become “tooling replacers” versus efficient troubleshooters.


The Junk Factor Measurement

This measurement is determined in the toolroom by the amount of physical frustration with overlooked features of old and new molds while being pushed to get them fixed. It can sometimes dictate how professionally a mold, die (or anything mechanical for that matter) gets worked on.

With a top-of-the-line junker, dealing with one too many unwieldy plates, cumbersome external components, a face full of water or oil along with thread-stripping, knuckle-busting, sharp-edged tooling stuck fast into inaccessible pockets, can turn a normally calm, professional, church-going repair technician into a vein-popping, wrench-throwing, trash-talking mold abuser.

A different reaction has been seen in older journeyman toolmakers that have walked into the repair shop in the morning, and upon seeing one of these high stress molds on their bench, gathered up all of their tools and walked right back out, never to be seen again.

Some molds—strangely enough—could start easily, run good parts at 100 percent cavity efficiency at the optimum cycle time and still be considered junk by the toolroom. Ask a repair tech how they like working on a mold equipped with a hot manifold that must be completely disassembled simply to replace a single thermocouple, or a mold with dozens of water fittings protruding from the bottom of a mold or no access holes to shoulder/stripper bolts. Characteristics such as these are what junktifies a mold and makes the repair memorable—not the fact that it always runs 32 cavities.

So at the end of the day the junk factor of a mold could have less to do with how it performs than how quickly and painlessly it is repaired on the bench.


Mold Spec Sheets

The following items are just a sample of what a repair technician would like to see included on every mold’s spec sheet (if they have a spec sheet, which is another article) before cloning takes place. These items concern ease of mold handling, disassembly, cleaning and assembly requirements versus mold function.

A mold could be considered junk if there is/are no:

  • Chamfering or rounding over of all non-critical edges on tooling and plates including through waterlines that always cut o-rings
  • Home tooling location numbers stamped on plates
  • Access holes to remove broken/worn dowel pins
  • Counter-bored (flush fit) water line fittings with “In- Out” stamped on plate
  • Through holes in mold plates to access shoulder bolts
  • Threaded, hardened and replaceable inserts in ejector plates for knockout rods
  • Grease grooves or graphite plugs in all (bronze) bushings. No more steel bushings!
  • Jackscrew threads in blind, pocketed cavity blocks
  • Use of standardized, off-the-shelf mold components (Why does anybody still custom build interlocks?)
  • Stainless steel everywhere (not always possible, but a nice thought)
  • Eyebolt holes on all four sides of all plates
  • Pry bar slots between every plate that is bolted together
  • Fixture to lift/hang the mold straight

Other repair technicians and toolmakers will easily add to this list of simple maintenance-oriented features that make a mold easier to maintain and work on, which translates to safer, quicker and more reliable methods of repair.

So if a tedious procedure or laborious repair task costs you money why would you clone these problems into another mold? This is a simple question for a bean-counter. They will ask how much not having this feature is really costing them. Is it more cost effective to pay for the improvement up front or to forget it and just deal with the cost of the task?

There are many areas of maintaining molds that cost companies money in excess tooling and labor every day. Obviously, how much money is the question. Due to the wide variety of opinions concerning how molds are run and maintained, determining true maintenance costs needs to be verified by a more accurate method than simply taking a shop poll.


Build It Better

Building a better mold does not always mean increasing every tolerance to a four-place decimal or adding more gears, cams, racks, rails or slick widgets seen in an ad. Nor does it always mean doubling cavity count, adding a hot runner system or other expensive design features.

Building a better mold means truly understanding how a mold performs in the press and what is required to keep it there. This can only be verified by putting a dollar amount to corrective actions necessary to clean, repair and maintain molds along with unscheduled mold stop reasons, defect types and frequencies. Many times it’s the simple things that get overlooked.

The ability to accurately relate maintenance costs to specific performance and maintenance characteristics on every mold will give you the true picture of what needs to be addressed on any mold being considered for cloning.