Archive for May 2017

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.