Archive for C&S Technologies

Upstream Quality Factors: Wire

A wire termination is a very simple process: take a wire and terminal, force them together using a range of crimping tools and voila, a crimped wire.

A quality crimp is altogether different. Not so much in the crimp process, it is is somewhat the same. But ensuring the wire performs well over the life of the product and the process to assemble that wire with repeatable quality requires specialized knowledge. And application of that knowledge to the crimp process. This is very critical in electrical assembly today with the cost of failure (rejects, re-work, loss of customer confidence, liability) being so high. Which is precisely why we publish this technical blog: to arm you with the knowledge and processing tools needed.

We have covered a number of topics directly related to crimp quality. Such as Headroom, wire to crimp process sensitivity. Also Crimp Tool Setup Variability. Using tools such as Crimp Cross Section Analysis and Crimp Monitors to validate and monitor crimp quality.

In this post, we are going to move “upstream” and consider the effect of the wire itself to the crimp process. Considering the elements of the wire and the effect on process variation. Also the process (cut and strip) to prepare the wire for crimping.

Reviewing and controlling all factors in the crimp process makes for more consistent results. And a level higher sensitivity to allow for a CFM to pick up small differences in the crimp process.

It all starts with quality wire. Consistent and repeatable material is critical to consistent crimp quality. And by extension, the ability of a crimp monitor to detect other defects related to the wire to terminal crimp process. Lot by lot and supplier to supplier consistency is important. Some of the factors in process variation:

  • Wire Stranding
    • Dimensions and Material.
    • Wire Twist.
    • Strand Count.
  • Insulation dimensions and material.
  • Wire Concentricity. Concentric wire allows for closer stripping of the insulation and ultimately better strip quality. Non-Concentric wire means the strip blades must be positioned farther away from the wire stranding to ensure the wire is not contacted by the blades, causing nicks and scrapes to the strands. Plus strip quality if affected.

Non-Concentric Wire

It continues with consistent processing methods. Wire Cut and Strip methods contribute to crimp quality in a positive or negative manner. Today’s technology motorized processing machines handle wire in a precision far better than previous generation machines. But they are far from infallible. In addition no matter how precise they are, external forces can introduce process variation that can affect the crimp process. Here are primary variables in wire cut and strip processing:

  • Strip Length. Length variation can be random or consistently high or low. Random strip length variation can be affected by the back pressure from the wire source. Consistently high or low strip lengths are typically programming errors from the process setup. Strip length variation can come from the processing equipment itself but is more of a rare condition than the conditions mentioned above.
    • Strip length variation whether random or consistent directly affects crimp quality. The conditions are the same whether an operator presents the wire to a “wire stop” in the terminal applicator or a swing arm on an automatic cutter presents the wire to the applicator. A strip length that is too short presents a high insulation condition where insulation is embedded in the wire crimp. Low insulation means the insulation is partly or completely out of the insulation barrel.

Example of Normal Crimp Curve

Example of Crimp with High Insulation

  • Strip Quality. A few conditions can affect strip quality:
    • Wire Concentricity. See above.
    • Blade Type or condition. Dull blades can cause residual insulation to enter the wire crimp. Universal V blades are good for most applications. But in some cases, no matter how much the blade setup is tweaked, the strip quality is not good. This could be due to the wire type. An alternate blade profile might be a better option. Such as a radius V style which cuts around the full periphery of the insulation.
  • Dirty Wire. This condition does not show up in a visual condition or as an error condition with a crimp monitor. It can affect the electrical properties of the wire. High electrical resistance is possible where contamination is severe. Contamination can be oxidation from wire that has been stored for a long time. In addition, residual oils or chemicals used in the wire production can be present.

Awareness of processing variables is critical. Applying this knowledge is even more critical. Employee training is important and could be considered one of your last lines of defense in detecting crimp defects. Good validation and monitoring tools are invaluable to assist in process control and improvement. Especially when your production depends on automation systems with high production rates. A lot of wires can be produced that are not possible to detect fast enough by a human.

Automate your setup validation to improve production efficiency and reduce the chance of setup error from the wrong information.

Crimp Quality Solutions is your end to end support for the terminal crimp process. We have the tools in your drive to take your crimp process to the next level. Do you have Crimp Monitors installed but do not use them? You are in the CFM Cycle. Crimp Performance Optimization is our solution to reactivate the crimp monitors to monitor your crimp process. Connect with WPS.

Headroom: Understanding Crimp Sensitivity

Last month we introduced Crimp Force Monitoring: Optimizing Crimp Performance. The CFM Cycle as described is a real situation that a number of companies find themselves in. Optimizing the crimp process can help to exit the CFM cycle.

A terminal crimp as simple as it appears, involves several inputs. Wire, terminal, crimp tooling, the crimp press and operator (bench) or automated machine are all factors which can directly affect crimp quality and ultimately the performance and longevity of the product the wiring is installed in.

Headroom analysis is a valuable indicator of Crimp Sensitivity. Headroom isolates the wire and terminal and the match between the two.

Headroom Defined.

Headroom is the difference in peak force between crimping the terminal with and without the wire. Headroom is typically expressed as a percentage. For example headroom of 85% means the wire represents 15% of the total peak force of the wire and terminal. The higher the headroom percentage, the more sensitive the crimp is for detecting small defects such as strands missing in the crimp. Conversely, the lower the percentage of headroom, the less sensitive the crimp process is.

What Can affect Headroom?

The terminal crimp size in relationship to the wire size is the main factor in overall headroom. If the majority of force is used to form the terminal only, then there is very little margin to add the force of the wire.

It is important to note that a wire of the same gauge but different strand count/strand thickness measure similar area. So headroom percentages are similar. But the strand count and individual strand thickness can affect the amount of strands a Crimp Monitor (CFM) can detect that are missing from the crimp. Here a few examples of headroom with different wire sizes and strand counts.

Crimp with Wire

Crimp without Wire

7 Strand Wire: Average Peak Force (wire and terminal) is 6.78 (kn). Average Peak Force (Terminal Only) is 3.82 (kn). Headroom is: 6.78 – 3.82/6.78 = 43.7%.

  • Each Strand represents 6.24% of the wire portion of the crimp. Using a +,- 3% CFM tolerance, this means the CFM can detect one or more strands missing.

19 Strand Wire: Average Peak Force (wire and terminal) is 10.9 (kn). Average Peak Force (Terminal Only) is 7.36 (kn). Headroom is: 10.9 – 7.36/10.9 = 32.5%.

  • Each Strand represents 1.71% of the wire portion of the crimp. Using a +,- 3% CFM tolerance, this means the CFM can detect two or more strands missing.

26 Strand Wire: Average Peak Force (wire and terminal) is 4.52 (kn). Average Peak Force (Terminal Only) is 2.70 (kn). Headroom is: 4.52 – 2.7/4.52 = 40.3%.

  • Each Strand represents 1.55% of the wire portion of the crimp. Using a +,- 3% CFM tolerance, this means the CFM can detect three or more strands missing. And randomly detect two strands.

These are three examples of headroom calculations. Each application will be different depending on the terminal crimp profile and wire.

It should be noted that the ability of a CFM to detect small variations is greatly affected by the capability of each input in the crimp process. What may appear to be a “false reading” on a CFM is actually variation observed by the CFM compared to the reference samples. For example, Press Shut Height or Crimp Force can cause variation when all other inputs are in control. So in some cases, it may not be possible to reduce the CFM tolerance to a lower percentage due to variation in one or more process inputs.

The terminal design can affect headroom. The overall crimp profile is affected by the end use of the terminal. In some cases the terminal may require a thicker base material and that can translate into more material mass being crimped. Making headroom less sensitive.

Headroom is one tool used to Optimize Crimp Performance. The CFM-Lite CFM for Bench Presses is from C&S Technologies. This is a powerful tool for not only monitoring the crimp process but helping to troubleshoot crimp applications. Headroom analysis is a part of the CFM-Lite platform.

C&S CFM-Lite

Crimp Performance Optimization is part of Crimp Quality Solutions, end to end support for the terminal crimp process. For more information on how we can support your crimp process or the CFM-Lite, Connect Your Way to WPS.

Understanding Crimp Tool Setup Variability

In the past, set up of an applicator to crimp a terminal was a time consuming process. Applicators were often bolted into the crimp presses and a manual adjustment to the press ram was made in order to provide the proper pull test between the wire and the terminal. Companies would acquire a large quantity of crimp presses and most high volume applications were permanently fixed to a press to reduce set up time. But at a cost of facility floor space. This was also a time when run volumes of one application were larger and spanned days and often weeks. That was then.

Today we have presses and applicators designed around a universal press shut height. Press bases and ram assemblies accommodate quick change of applicators. The applicator adjust-ability is quick and the press is only adjusted to account for tool wear.

Applicator and Crimped terminals.

Despite the commonality of applicator setup, each setup needs to be treated as unique. This is even more important when crimp monitors are deployed and configured to detect small crimp variations. That does not mean significant extra time for setup. But extra effort to ensure the setup is done right and initial samples are validated and meet the quality specifications.

So what can vary from setup to setup? Let’s break those down.

Presses which are routinely adjusted to match the proper crimp height and pull test mean each application can vary from it’s intended crimp spec. As a general practice, the press should be returned to it’s calibrated shut height position after each job. When the press adjustment uses a graduated scale with positive adjustment points makes the change back to the calibrated position more predictable. When no positive adjustment of the shut height is available,then exact position of the shut height is not possible without re-calibration.

Micro-Adjustment of Crimp Press.

Presses have their own variation from press to press. If the applicator is installed in a different press, this is a source of variation. The way the applicator is installed in the press can affect the setup. Dynamic Press Analysis is a way to determine piece to piece variation within a press and between presses.

Applicator service and crimp tool replacement is a source of variation even when the same wire and terminal are used.

Wire of the same gauge but with different strand quantity and diameters is a source of variation. Crimp compression can affect electrical resistance and compression of the strands can vary with the stand thickness and number of strands. A wire with 19 strands will compress differently than a 41 stand wire.

Different wire gauges crimped to the same terminal. Each terminal has a range of wire it will crimp. The crimp geometry is designed to match the wire range. Generally speaking a terminal supplier will attempt to fit as many wires into one crimp size. Mainly to reduce the amount of terminals to produce and stock. A wide range of wires in one crimp section can affect headroom when using crimp monitors. Headroom is the difference between the force to crimp the wire and terminal and the terminal only. More headroom equals the ability to detect small crimp defects.

Different lots of terminals and wire. Variation can exist from lot to lot of materials.  Over the years, that lot to lot variation is smaller due to tighter process control by the supplier. But variation can exist so validation when materials (wire barrels/reels or terminal reels) change, a re-validation is recommended.

So why is this important? Consistency in setup is critical for consistent crimp quality. Especially when crimp force monitors are being used for in process monitoring. Crimp monitors can be affected by piece to piece variation from equipment wear, material matching and in process material changes. The more consistent these elements are, the more sensitive the process is for the monitor to detect smaller defects.

Conversely the less sensitive the process is, the more difficult it is to detect small defects. And the greater the risk of accepting defect parts.

Improving your current crimp process is ongoing. Reducing sources of variation gives a higher level of confidence in your ability to deliver a high level of quality assemblies to your customers.

Don’t know where to start? Crimp Quality Solutions can help.

An Appliance Recall. Breaking down the Cause of Electrical Failure.

As I write this, a name brand manufacturer of appliances is adding to the list of recalled Dishwashers from defective power cords. The power cord can overheat, causing a serious fire hazard. The recall extends several years and affects a number of models under different brand names. I am not going to name names, a simple internet search can give you all the information on this recall. What is significant about this recall is that there were five reports of property damage which has affected over 600,000 models. A relatively small cost part over five failures has created a massive recall involving two countries (USA and Canada). Risking hundreds of thousands of lives on top of monetary cost and cost to reputation.

We are going to drill down to the cause(s) of the component failure. Also the greater implications of all manufacturers of electrical components. And how preventative measures by applying tools and quality practices can greatly reduce the risk of component failure.

What Causes a Power Cord to Overheat?

High electrical resistance at any point along the length of the cord is a typical culprit for  excessive heat. High Electrical Resistance is caused by a number of factors. In the case of a wire assembly some factors are outlined below:

  • Wire size too small for the rated current that flows through it.
  • Connector Crimp and Wire are not properly matched.
  • Poorly crimped terminals
  • Crimp Equipment.
    • Not set up correctly.
    • Worn Tooling
    • Inconsistent Crimp Press Force.
    • Crimp missing strands.

Crimped terminals are a core connection in a wire assembly and can be a source of high electrical resistance.   High resistance in crimped terminals is directly attributed to too low and in some cases too high compression of the wire strands within the crimp. There is a direct correlation between crimp compression and electrical resistance. Crimp compression cannot be determined without cross section analysis. Pull test does not provide an accurate measurement of crimp compression (and by extension: electrical resistance). In some cases, pull test can actually decline slightly before resistance peaks.

There is a direct correlation between crimp compression and electrical resistance.

Terminals that have a crimp barrel that is too large for the terminal can cause low compression. Improper crimp tooling can also contribute to inconsistent crimp quality. Worn crimp tools, improper crimp tool setup and press force that can vary from piece to piece can also lead to inconsistent crimp quality.

Wire stripping equipment can also cause inconsistencies. Worn blades or improper machine setup can cause cut strands.  Cut strands can reduce the total compressed area in the crimp which can increase resistance.

Prevention is the Cure.

The difference between this recall taking on the dimension it has and not even happening at all could be simply a few missed checks in the assembly process. We are going to get really specific and focus on the terminal crimp process. Consider the following:

  • Knowledge of the assembly process is critical. But it is not enough. Assuming wire assembly is a simple process that does not require constant monitoring can be a critical mistake.
  • Understanding each factor in assembly and their inherent variability is important. In the case of crimping a wire to a terminal, there are five basic elements to consider. Any of these factor which are not in control can affect quality.

Where do you start?

Manufacturing Machines are well maintained and capable of repeatable piece to piece consistency. Static calibration and single piece measurement does not guarantee statistical capability. Dynamic measurement provides the way to measure process capability and repeat-ability.

Tooling is replaced before quality is affected.

Manufacturer’s Specifications are a critical start to a process validation.  Suppliers spend a significant amount of resources in developing components and the associated assembly instructions and quality standards. For example, quality standards for terminals include crimp height measurements and minimum pull test standards.  Crimp Height measurements are created which are based on optimum crimp compression.  Validate using Crimp Cross Section Analysis.

Use the Right Measurement tools. For terminal crimp height, use crimp height micrometers. Other measurements can be made by blade micrometers or dial calipers. Pull test as a secondary measurement. Cross Section Analysis for more in depth analysis of the wire under compression.

Crimp Height Micrometer

Correct Materials are used. Ensure the wire is matched to the terminal based on the supplier’s specifications.

Measure when material lots change. Materials within or between lots can cause variation in the crimp process. Re-Measure to assure there no changes in materials.

When a failure occurs of this magnitude, it can be a wake up call for the companies involved. But it also can be a valuable lesson to others.  Don’t take a chance with the future of your company. Ensure your crimp process is validated and monitored prior to and during the production process. Crimp Quality Solutions provides valuable tools and knowledge for the terminal crimp process.

Crimp Quality: Scaling it to Fit.

“Quality is never an accident. It is always the result of intelligent effort” – John Ruskin

I am sure this quote from a 19th Century English Art Critic was applicable in the era it was written.  But it is no less applicable today.

“Quality is never an accident”. Nor does Quality simply happen. It takes effort to create, build and maintain an effective quality system. The stakes are higher today than any other time in history. The cost of a reject or recall can cripple a company. No company of any size is immune from the effects of a reject claim. Can you afford the risk?

“It is always the result of intelligent effort”. Yes, you must invest time and resources. People in the company from the top to the bottom need to be actively participating in efforts to create a quality system. Ask yourself these few questions:

  • What does our existing quality system look like?
  • Is it contributing to reduced internal rework costs?
  • Is it effective to reduce the risk of defective goods leaving our facility?
  • Do we have sufficient internal resources to improve our Quality System?
  • Do we need to consider outside sources to ensure we are keeping up with emerging trends in Quality Management?

Putting it into perspective, a quality system needs to fit the company’s size and structure. What is critical to large companies with big supply contracts and the associated requirements to fulfill may not be applicable to a smaller company. But even a small company should have a basic system of Quality which should be enhanced over time. Let’s get specific and drill down to the topic of Crimp Quality. Considering the pre-production validation and process monitoring, consider the essential tools for a basic Quality System:

Validation

  • Crimp Height Micrometers
  • Blade Micrometers (or Digital Calipers)
  • Pull Tester
  • A system of recording measurements

In-Process Monitoring

  • Validation Tools above
  • Crimp Force Monitors on bench and automation mounted crimp presses.
  • Visual Inspection Requirements
  • Requirements for Frequency of Measuring production

What Else?

Knowing what a good crimp is (and isn’t) is not evident with a visual external inspection. You need to look inside. Often a view of the interior of the crimp can quickly provide clues to conditions which can affect quality and contribute to increased processing costs of rework. For example:

  • Constant Crimp Force Monitor Alarms (avoid the CFM Cycle)
  • Wire assembly failures. High electrical resistance which can cause an overheard electrical connection.

For this you need to Cross Section the Crimp. This gives you a view into the material matching (wire/terminal) as well as the process tooling.

Bend Angle is a condition from the terminal crimp process. As a wire is crimped to a terminal, material is extruded outward and can cause the terminal to bend (banana shape). This condition can cause mating issues when connectors are mated together. Also, a potential of high electrical resistance in extreme cases of mating miss-alignment. An emerging measurement requirement in USCAR 21 for automotive wire harnesses.

Networking Crimp Quality.

Software and hardware networking are becoming more economical solutions to handling data. The right automated solution can reduce pre-production validation time and errors from manual data entry. Also, it removes subjectivity from validation and in-process monitoring (it looks like a good crimp therefore it is a good crimp – a big mistake in thinking). Do you Trust or Validate?

What about Equipment Maintenance?

Most companies have a maintenance program for their processing equipment. But is it effective enough? How many crimps from a set of tooling? I have calibrated our crimp press(es) but have I determined its (their) capability to produce repeatable crimp force and shut height?

Knowing comes before Doing.

Let’s face it, we are not experts in everything. Nor should we pretend to be. It is easy to start without the knowledge of what is needed. But is it effective? Industry Experts can come alongside your personnel to guide the process and provide critical advice to focus your efforts.

Scaling Crimp Quality is important in all companies who process wire assemblies. One size does not fit all. If you already have a crimp quality system (which we hope you do), what knowledge and tools do you need to make your system better. If you do not have a crimp quality system and no reported quality failures, the clock is ticking for one which could come. Don’t take the risk, obtain the knowledge of what is needed and get started with the basic tools.

Crimp Quality Solutions could help you. Connect with us and Let’s Get Started with an assessment of your current condition.

Quality on the Plant Floor: Trust or Validate? 

We live in an environment of automation. Everywhere there are new developments in systems for making our lives more convenient. Our smartphones have become “smarter” with virtual assistants that have the right answer at the right time. Casual dialog is filled with terms like “virtual reality”, “artificial intelligence” and “the internet of things”. People are more connected now than any time in human history.

As the plant floor is automated how do we mix people decisions with those made by machines? Do we continue to trust the good but perhaps biased intentions of a worker. Or do you free them from routine decisions with the assistance of machine based systems?

We will dive into this topic and specifically in the crimp validation process. What is the decision process for the wire termination your worker has in their hand before they start producing wires? That decision has far reaching implications. Here are a few points for consideration.

Good information is critical.

Quality standards are derived from the source of the material. In the case of electrical terminations the terminal supplier is your source for measurement standards. Factors such as crimp height and width for wire and insulation crimps, pull test and visual standards. Also associated tolerances.  This information should be collected for each process setup and can be stored into a server computer.

Although not a core part of this discussion, the proper tools are also critical. For Crimp Validation, use only Crimp Height Micrometers for measuring conductor crimp height and calipers or blade micrometers for conductor crimp width as well as insulation crimp height and width. Pull test as a secondary measurement of crimp secure-ness and Cross Section Analysis to verify the internal crimp shape.

A system to pass that information to the personnel on the plant floor.

Good information is useless unless it is available for proper pre-production validation. Connecting client computers at locations on the plant floor or data entry modules on the processing machines provides provides an access point to retrieve the validation standards required. Also a potential portal for entering validation data for trace-ability and analysis.

A process that removes subjectivity from the decision to start production.

The operator of inspector has a pre-production crimped wire in their hand. At this point how do you verify the wire has been measured and meets all of the established standards. Or a few measurements pass and a few do not.

Without adequate controls, subjectivity be the plant floor personnel can creep in. Perhaps the rush to get into production can pressure personnel to cut corners and accept parts which do not fully meet quality. No matter how well trained personnel are, they are the last line of defense in pre-production and opinions can affect judgement.

Locking the equipment out of production until pre-production samples pass quality test is an important move. It is important to assure your personnel that this is not personal against them. Rather it protects them from fall out in failure conditions.

A properly configured network system with modules on production equipment can perform the dual function of production validation and release of the processing equipment for production.

In-Process Changes affecting Quality

Any change during production is an opportunity to introduce variation into the process. In the case of a wire termination, changing wire (reel or barrel) and terminal (reel) can change the process. In the case of applicator tooling, when the applicator is removed for maintenance like crimp tool changes, this is also a possibility for variation.

This presents you with two options: you can continue without validation or validate when the process changes. Not validating represents a risk which is hard to quantify. Material suppliers and tooling can have varying effects. The safer option is to perform a validation to confirm the changed process matches the initial validation. Having the ability to lock out the process equipment after a material change or maintenance and forcing a validation is a good practice. This removes any subjective opinions from creeping in.

Measure, analyze and improve.

What gets measured gets improved.  Having good information as a baseline is a good first step. The next step is analysis. Considering the strengths and weaknesses. Focusing on those areas that can contribute to long (or short) term failure in a product. Then acting on the analysis. This is fundamental to any quality improvement process.

There is a great amount of information that can be pulled from validation and in process monitoring of production. The important factor is the system. You can pick a manual method or automatically collect data from production machines and other measurement sources. Choosing an automated method removes a significant amount of manual data entry not to mention the potential of transposition error.

Tying it all Together.

You likely have most of the piece in place to automate the quality process. From production equipment to the measurement tools to validate and monitor output. Having a central server with validation standards and production data is a gateway. Connecting the components together provides the pathway for good two way communication between the plant floor (people and machines) and the server with the data collection and analysis capabilities to turn raw data into useful information for analysis and quality improvement.

Crimp Quality Solutions and our Global Technology Partnership with C&S Technologies is your source for the technology needed in an ultra competitive manufacturing environment.

Connect Your Way to WPS and Let’s Get Started.

How Do You Inspect Your Crimps? A Seminar Review

At the 17th Annual Electrical Wire Processing Technology Expo, Terry Curtis President of WireProcess Specialties presented the seminar “How Do You Inspect Your Crimps?”. This seminar was presented as a teamwork effort between WireProcess and our Global Technology Partner: Crimping and Stamping Technologies.

The seminar was presented to a capacity crowd at the Expo. This speaks into the need for more information on crimp validation techniques. Crimp Quality is a topic we as a company are passionate about.

Terry Curtis, WireProcess Specialties at the 2017 Electrical Wire Processing Technology Expo.

 

Terry started the discussion by stating ” it only takes one bad crimp”. It only takes one miss-applied crimp to render a wire harness defective. There are a range of implications from repair of the affected harness to in house sorting of larger batches of harnesses. Certainly the customer relationship can be affected with legal liability a possibilities in severe cases. Can you company afford the risk?

A Quality Crimp: It All Starts Here.

A quality crimp starts with fundamental crimp specs, typically established by the terminal supplier. This includes the physical geometry of the crimp section, visual attributes and measurement standards. An emerging specification (bend angle and parallelism) which affects the mating of connectors was presented.

Bend Angle can cause interference issues with connector mating.

An excerpt of a comprehensive study into crimp compression as it affects electrical resistance was shared to illustrate the co-relationship between compression and electrical resistance and the effect compression has on mechanical crimp strength (Pull Test).

The take away from this section was the terminal suppliers based on their design and testing of crimp geometry produce a “Recipe” to follow. The end user’s task is to “Follow the Recipe”.

Apply the Recipe.

Pre-Production validation involves taking the “Recipe” and ensuring the specifications are met. Prior to production start. Required measurements, methods and the proper measurement tools were discussed. Visual inspection was also covered as well as a few tips on how to spot a wire under compression in a terminal were uncovered.

The shape of the terminal, measured through Cross Section Analysis shows how the crimp tools form the terminal and the distribution and compression of wire strands. A good indicator of crimp to crimp consistency and a factor in “false CFM readings” (which are not really false at all).

Production Monitoring.

Validation alone is not sufficient to assure the quality will be maintained through the production run. Factors which can affect quality during the production run were discussed. Also stressed was tools which are used in the validation process are also used to measure crimp quality during production.

A Crimp Monitor (CFM) is an essential tool in process monitoring. The CFM provides 100% real time monitoring of crimp force and detection of typical crimp defects.

The CFM Cycle, a topic introduced in our 2016 seminar outlines what can happen when constant alarms from a CFM are not investigated for their cause and CFM tolerances are opened up to stop the CFM alarms.

Applicator and Press Capability and Maintenance.

Applicators and Crimp presses are the two critical processing tools for the crimp process. Maintaining this equipment to ensure they provide statistically repeatable crimp performance.

Ensuring the Applicator crimp tools are within the manufacturer’s specifications is the most critical attributes of an applicator. Also important are feed and cut off system and general wear of the applicator body and feed track.

The press is the common factor and sees more wear and tear than an applicator which is removed after production. Assuring the shut height is calibrated is one factor. But statistically repeatable shut height and crimp force is required to assure consistency during production. Press Analysis is a very important aspect of equipment maintenance.

As illustrated below, a repeatable press (Shut Height and Press Force) equals smaller tolerances with the CFM which means the CFM’s ability to detect smaller defects is increased. The converse is true when a press is not repeatable. This equation also can apply to the Applicator.

Networking.

A validated crimp indicates the recipe is followed, and production monitoring assures the process stays within the validated tolerances during production. But what about your plant personnel? What happens when all of the materials and processing tools converge for production?

  • How can you be assured that the right materials and tooling are used? And what about validation specifications. Are they followed?
  • What about material and tooling changes, how do wire and terminal changes as well as applicator maintenance affect the initial validation?

Networked production equipment and measurement is a way to assure the right materials and tooling are deployed. Also measurements attributes are validated and re-validation occurs when process parameters change.

Management Support.

Any quality initiative lives and dies with Management support. Management needs to be actively involved in assuring resources are acquired and deployed, personnel are trained, systems are created and they measure the overall improvement of quality. Cooperation between functional areas (production, quality, set up and maintenance) are ensured.

How Do You Inspect Your Crimps? A fundamental understanding of crimp development and validation techniques is an important first step. Production Monitoring ensures validation specs are maintained through the Production cycle. Using the right tools for both Validation and Monitoring is very critical. Maintaining production equipment is also critical to assure consistent piece to piece results. Networking ties it all together and removes some of the routine decision making from plant floor personnel. Quality Improvement programs live and die with Management support.

If you are evaluating your current crimp quality system, get started right with Crimp Quality Solutions. End to End support for the terminal crimp process. Ready to get started? Click here.

Crimp Quality Solutions: Validation and Monitoring Technology

In this final part of the introduction to Crimp Quality Solutions,  we are focusing on the tools used to validate and monitor crimp quality. Part one was an Overview of Crimp Quality Solutions. Part Two covered Training and Support Services

It is simply not enough to know what needs to be done, you must apply the knowledge and translate it to action. In today’s production environment,  there is little room for error. Wth razor thin margins, quality issues can be costly to an organization. Not only in hard currency (returns, rework etc..), but also in reputation. Avoiding quality issues is critical to a company’s future. Cutting corners is not a solid business strategy.

To assure your terminal crimps are the best quality from part one to the end of a production run, the right tools must be used. It should be noted that there is a convergence in the use of Quality measurement tools between pre and in-process monitoring.

Here are the essential tools used to validate and monitor crimp quality.

Press Analysis

If you have calibrated your crimp press to the standard shut, your press has demonstrated capability for shut height alone…. for that one piece. In order to determine the press is statistically capable, shut height and press force need to be evaluated. And that requires more than one press cycle. The PAL4000 Press Analyzer accomplishes a full capability study of the press. And it stores the data for comparing with past press studies. Maintenance will benefit by prioritizing press service.

Crimp Height Micrometer

A Crimp Height micrometer is critical to measure the wire crimp height during validation and process monitoring. The flat anvil rests on the top of the crimp while the pointed spindle rests in the underside (center) of the crimp.

Blade Micrometer

Other measurements like wire crimp width, insulation (height and width) as well as strand diameter. Digital Calipers can also work, but resolution (two decimals) is lower than blade micrometers (three decimals).

Pull Tester

As a secondary crimp test, pull testers measure the secureness of the crimp. Motorized pull testers pull the wire at a constant rate and takes out the operator (or operator to operator) variation. Automatic data logging reduces time and potential for entry error.

Crimp Cross Section

What was once a dedicated crimp development tool in large wire harness and terminal stamping companies can now be found in quality departments and and the production floors of a wide range of companies. Quick sample preparation and imaging are standard features. X-Scan is a powerful software analysis tool with automatic crimp profile tracing and a full list of crimp attributes.

Crimp Force Monitors

Crimp Force Monitors are a standard quality tool in wire harness production. Crimp Monitors use force sensors mounted to the press and convert force to a crimp curve which when compared with pre-production validation samples, can detect typical defects such as strands missing and insulation in the crimp. Crimp Monitors are mounted to both automatic processing machines and bench top presses.

Networking

Processing inputs for crimping include the operator and process tools (crimp applicator), materials (wire, terminals). Crimp tests include crimp height, pull test, cross section and Crimp Monitor teach in. Verifying this information prior to production is possible but prone to human error. Automating using a client/server system takes error out of the process by comparing processing inputs with established standards stored on a server computer.

Our Global Technology Partners Crimping and Stamping Technologies are highly specialized in the crimp testing process. An authority in a crimp validation and process monitoring, C&S supplies all of the above technologies and are constantly adjusting their processing solutions to meet new demands of the wire processing industry. That and the global support provided by their experienced technicians make C&S a valuable partner in crimp quality.

No matter where you company is in it’s wire harness journey, WPS and C&S have you covered. We are there to support your requirements from end to end.  Visit CrimpQuality.Solutions and click the Let’s Get Started Link.

Connecting the Dots: Pre-Process Validation to Production Process Monitoring 

By their body language and words, companies say it all;

“Why monitor our crimp process with more than the most basic of tools? After all over the years, our products have performed with no problem without adopting more than is necessary?”
On the surface this may be true. But lurking under the surface are problem issues that can costing your company now and in the future.

Consider the following scenarios:

  • Internal process rejects or rework that goes unreported. Like a bad crimp that is simply clipped off and an operator re-strips the wire and crimps a new terminal to the wire. Adding variation to the process by manually processing the wire without validating the results.
  • Mismatched wire and terminals. A mismatch between the terminal and wire, especially the terminal being too big for the wire can cause excess variation in the crimp process and electrical performance issues like high resistance. Process variation is a hidden cost to production while high electrical resistance is a potential long term product failure.
  • Worn production tooling creating batches of parts which can create assembly issues upstream. Deformed terminals from compensating for worn tools are one problem.

Mainstream OEM terminal suppliers invest an extensive amount of resources to ensure the connector they design performs properly on the factory floor and in the actual product over it’s life expectantly. They provide the processing test requirements to assure the terminal is assembled properly. So why do so many companies not validate their assembly to the recommended specifications, never mind monitor their assembly process?

Consider the Cost of Inaction (the status quo) as a reason.

So let’s talk about the transition from pre-process validation to process monitoring. For that you need to think about this fact:

In a lab environment, processes are controlled and highly repeatable. In a production environment, external variation exists which can affect the final product quality.

Without real time process monitoring, depending on single or spot in-process inspections does not give you any solid information on the capability of the terminal crimp process. And that is a missed opportunity for process improvement which can provide improved efficiency and reduced process costs. Which is the Benefit to the Cost of Quality.

One important point to remember is that process monitoring tools do not improve quality in and of themselves. But they can raise issues on individual setups which should be reviewed at the time. Otherwise you can be trapped in the CFM Cycle.

Using the right tools in crimp development and validation in addition to process monitoring can provide the opportunity to improve crimp quality. Establishing a base line of quality and deploying a quality improvement strategy can reap great dividends in cost reduction, customer retention and potential for new customer acquisition.

CrimpQuality.Solutions provides end to end support with your terminal crimp process.

Crimp Quality Solutions: Training and Support Services

Training, Consulting and Support Services are an integral part of Crimp Quality Solutions, part of the WireProcess Specialties portfolio of solutions for processing wire assemblies.

One of the strengths of WPS for almost four decades has been in the supply of terminals, crimp tooling and crimp monitoring systems. It has become evident that a comprehensive offering to our customers is needed. Which is beyond the physical acquiring and deployment of components, processing and process monitoring monitoring equipment.

For example, consider this statement:  Installing a Crimp Force Monitor does not improve quality. See our article: Crimp Quality Monitors Do Not Solve Your Crimping Problems.

Our engagement starts first with an assessment of your current crimp process. We can perform this either in house or through a virtual connection.

Training material is custom tailored to the company’s needs with one or more of the following topics:

  • Pre-production crimp validation
  • Crimp Process equipment set up
  • Pre-production crimp testing
  • In-process monitoring
  • Documentation

Training can be performed in house or via webinar.

Crimp Quality Solutions Support Services are a vital link in the implementation of a Crimp Quality improvement strategy. Our in house Crimp Cross Section lab gives you a start in documenting crimp conditions. Crimp Press Analysis assesses the condition of your crimp presses, a critical component of your crimp process. Crimp Cross Sectioning is a vital tool in validating and process monitoring a crimp. Cross Section provides a peak inside the crimp and tells a lot about the performance of the crimp process and inherent variation.

Crimp Quality Solutions provides you with end to end support in your terminal crimp process. Let’s Get Started with your crimp process.