Crimper Kit Calibration

Crimping technology allows for a high-quality connection at a low cost by eliminating the need to solder connections between terminals and wires. Crimper kits (a set of crimp tools) have become standard equipment in several industries, and are designed to deliver complete wire harness solutions for machines in the manufacturing, offshore, marine, military, and commercial aviation sectors. OEMs such as DMC provide crimp tool kits tailored to machine or aircraft type to comply with the wiring standards of stripping, crimping, and terminating electrical connections.

Crimper Kits – Design:

Designing a tool kit to service an entire wiring system of a complex machine or aircraft necessitates significant study to pick appropriate tooling and ensure that all serviceable connections, terminals, splices, and contacts can be properly maintained. Wiremen or specialists in charge of the maintenance or repair of these systems are not usually expected to know to crimp and terminate standards, nor do they have the time to perform research or locate toolings.

Crimp tool OEMs perform this electrical research on the machine, and with the tooling database available, tool OEMs develop a standard Wiring System Service Kit for a particular machine. A tool kit package includes All the necessary tooling (crimping tools, dies, heads, installing tools, removal tools, gages, wire strippers for circular and R.F. connectors, and more), valuable tool application data to guesswork while performing a crimping operation, and complete instructions on set up and use of each tool and accessory.

Crimper Kits – Types and Selection Criteria:

The quantity and types of crimp tools in a crimp tool kit are proportionate to the electrical system’s complexity. For example, large aircraft need heavy-duty pneumatic indentation crimpers that work with a button push. These powerful crimp tools can handle contacts up to 8/0 (AWG) size and are compatible with onboard air sources operating at 90–125 psi (5.4–8.16 BAR).

On the other hand, small aircraft electrical wiring and harness needs are fulfilled by manual crimp tools. Crimper Kit makers often supply standard kits (labeled with a list of equipment) for the aircraft and industrial machinery, making kit selection easier. If a standard kit is not available, the electrical system has to be studied to build the kit.

To help easy recognition and increase productivity, each crimper kit includes the nameplate, foam pads/inserts, contents charts, instruction sheets, and tool selection charts. The external case is often made of fiberglass, steel, or copolymer polypropylene material and can be selected based on the application and operational environment.

Crimper Tools – Calibration and Pull Tests:

Although a crimp tool is not a measuring instrument, it should be calibrated and maintained according to design criteria and manufacturer recommendations to guarantee accurate crimping and security. Crimp tools should be checked for accuracy at least once each year or after 10,000 crimps have been achieved, whichever comes first.

The Go/No-Go Pin Gage Test, the Crimp Height Measurement Test, and the Crimp Pull Test are three critical tests that must be completed on crimp tools to ensure they are functioning as designed. Some of these tests may not be appropriate for all crimper types, so the manufacturer documentation should be consulted to determine the correct tests for the crimping tool being tested.

1. Go/No-Go Pin Gage Test: It is critical to periodically check the tool with an Inspection/Verification Gage (Go/No-Go) to ensure that it functions correctly. The Go/No-Go test ensures that the tool’s settings/tolerances have not been altered after installation or calibration. Select the proper Go/No-Go Gauge and follow the instructions on the gauge and tool directions. The tool must be set to the desired depth using the depth selection and inserting the “Go” end of the gage into each indenter.

The dimensions and physical characteristics of the tool should match design standards, as indicated by the “GO” passing freely between the four indenters and the “NO-GO” being able to enter but not pass through the indenters. For crimp tools with multiple dies for each crimp die that needs testing using the matching, pin gage needs testing for the die opening. Most crimping tools include settings to return the tool die to within manufacturer standards if necessary.

2. Crimp Height Measurement Test: This test checks to ensure that the crimp assembly measurements meet the manufacturer’s requirements for crimp height after a test crimp is completed. A blade or point-type micrometer is required for this procedure. To perform the test, a wire and appropriate connection are placed in the crimping die, and the tool handle is secured until the ratchet mechanism releases or the dies are entirely closed. The crimping assembly is then taken out to measure the required test points as indicated in the kit OEM with a micrometer.

All measurements must be accurate according to the manufacturer’s requirements. To calibrate and verify the accuracy, repeat this procedure for each crimp die on the tool.

3. Crimp Pull Force Test: A crimp tool calibration often requires a test crimp subjected to a pull test. Pull tests are mainly performed to determine the mechanical strength of a crimp termination. Pull testing is done with a Tester device that clamps the wire, pulls at a defined speed, and measures force using a load cell. A pull tester also can be as simple as hanging fixed weights on the wire for a minimum of one minute. Manual and motorized pull tests can be performed with the crimp tools.

Motorized Crimp Pull Test – Operational Procedure:

Motorized Tensile Wire Crimp Pull Testers are used to test a crimp contact’s or terminal’s tensile strength, according to UL, ISO, SAE, MIL, and ASTM tensile test requirements. The testers typically have the range of 2.5 lbf to 250 lbf and include digital data logging capability for exporting test data to a PC via USB or RS-232 protocols. Following is the step-wise procedure to be followed for a Crimp pull test:

1. Cut wire length 6 inches (152 mm) long and strip one end to 1/2 inch (13 mm) or long enough, so no wire insulation is under the insulation grip, or loosen the insulation crimp so it has no hold on the insulation of the wire.
2. Terminate the appropriate terminal to the wire to the nominal crimp height. Visually inspect the termination for bellmouth, wire brush, and cut strands.
3. Set the Crimp pull tester to 2″ per minute (50 mm/min). If necessary, knot the UN-terminated end of the wire (If insulation slips on the wire).
4. Regardless of pull tester type, both wire and terminated end must be securely clamped and activate the pull test.
5. Record pull force readings. A minimum of 5 pull force measurements should be done to confirm each set-up. A minimum of 25 readings should be taken for capability.
6. Compare the lowest reading to minimum pull force specification.

Standards for Crimp Pull Testers:

The standards lay out procedures to determine the pull-out force of terminal and wire connections, although specific standards do not specify how to capture the elongation. The following are standard procedures followed while performing Crimp pull tests:

1. SAE/USCAR-21: Performance Specification for Cable-to-Terminal Electrical Crimps USCAR21. This specification defines basic test methods and requirements for solder-less crimped connections.
2. VW-60330: Volkswagen Crimp Connections, stating the procedures to be followed for Solderless Electrical Connections.
3. BS EN 60352-2:2006+A1:2013: Solderless connections – Crimped connections. General requirements, test methods, and practical guidance.

Crimper Kits Calibration and Maintenance – Why is it essential?

Modern technology and aircraft are built to accommodate a wide range of needs that necessitate intricate electrical wiring systems with numerous types of connections, contacts, and terminals. Precision tools are required to maintain and repair these electrical networks correctly. To ensure the safety of your equipment, comprehensive tools and maintenance kits are essential to meet the service demands of modern machines’ electrical wiring systems.

Crimping and cutting tools are supplied in crimper kits, allowing you to strip, crimp, install, and remove the typical contacts and terminals of this wiring system. Because the instruments are conveniently packaged together with their usage instructions in a single kit, connector repair and troubleshooting may be completed in the quickest time possible, allowing for a rapid return of machine or aircraft to service.

With a regular Calibration and Maintenance program, Crimper kits provide the following advantages to aircraft operators and machine owners: simpler access to tools, less personnel downtime, tool inventory control, and tool protection. Therefore, regular kit calibration and maintenance are critical for equipment owners to maintain machine availability.

e2b calibration offers industry-leading ISO-certified crimper kit calibration services. Our labs are ISO/IEC 17025 accredited and operated by a team of qualified calibration experts to test and calibrate your tools. Our verifiable services are unmatched in the industry. We are registered with ANAB. We are also ANSI/NCSL Z540-1-1994 certified. We have the NIST Traceable Wide scope of ISO/IEC 17025 accreditation. Contact e2b calibration for all your equipment calibration needs.