Automated wire harness crimping machine

01

Read a machine specification: a worked example

Hechang's HC-10 fully automatic machine cuts and strips wire and crimps one end. Its specification table lists wire sizes of 0.03–2.5 mm² (AWG 30–13), a 1.5-ton crimping capacity, cutting length 40 mm to 99,999.99 mm with a tolerance of ±0.002 × L, stripping length 0.1–10 mm, compressed air at 6–6.5 kg, 165 kg weight and 4,000 pieces per hour, with detectors for wire presence, wire overload, strip error, terminal presence and crimp error. [2]

The same page's feature list describes a 2-ton servo press and wire range of 0.1–3 mm² (AWG 32–13), which differs from the specification table; ask the supplier to confirm force and wire range in the quotation. [2]

Editorial calculation: 4,000 pieces per hour is 3,600 ÷ 4,000 = 0.9 s per piece; at 500 mm cut length the ±0.002 × L tolerance is ±1.0 mm. [2] Ask for rate at your lengths and terminal type, not the maximum.

Give the supplier the wire types and cross-sections, terminals and seals with part numbers, cut and strip lengths, one- or two-end crimping, required output per shift, crimp monitoring and traceability, applicator compatibility, air and power supply, and acceptance samples.

02

Prove crimp quality with pull testing

NASA-STD-8739.4A, the agency's crimping and harness workmanship standard, sets minimum crimp tensile strengths for copper stranded conductors: for example 36 N for 24 AWG, 57 N for 22 AWG, 92 N for 20 AWG, 142 N for 18 AWG, 183 N for 16 AWG and 290 N for 14 AWG. Combinations not in the table must reach at least 60% of the wire's tensile strength. The test pulls at 25.4 ± 6.3 mm per minute. [1]

For production control, the standard requires pull tests of each tool and contact-conductor combination at the start and end of each shift or production run, with zero failures out of three samples before production proceeds, records traceable to the contact, wire, tool, setting and run, and hardware made before a failed test treated as suspect. Adjustable crimp tools must be set, sealed or locked and verified before use. [1]

Editorial calculation: testing at both the start and end of a shift uses 2 × 3 = 6 destructive samples per tool and combination per shift, unless the standard's rule for skipping a test between consecutive shifts applies. [1] Hechang also lists pull force testers and crimp micrograph analysis equipment. [2]

03

Cut-strip-crimp, double-head, ferrule and crimp-and-tin machines from eight listed makers

The listed makers range from fully automatic cut-strip-crimp machines (Hechang, Wirepro) and double-head terminal machines (Kunshan Bolun) to ring-lug and ferrule crimpers (Kunshan Yuanhan, Qingdao Jingchengwang) and crimp-and-tin machines (Bettertech).

Hechang, Kingsing, Bozwang, Bolun and Wirepro list fully automatic cut-strip-crimp machines; Yuanhan lists stripping-crimping and ring-lug crimping machines; JCW lists stripping and crimping machines including ferrule crimpers; Bettertech lists terminal crimping and crimp-and-tin machines.

04

Check a double-ended machine's stations, limits and sample rule

Schleuniger's datasheet for the CrimpCenter 36 S, a fully automatic machine that processes both wire ends, shows what a two-sided specification adds to the single-ended example above. It lists up to 6 processing stations with a maximum of 3 crimping stations, wire lengths of 55 mm to 65 m (optionally from 35 mm), stripping length of 0.1 to 18 mm on each side, wire cross sections of 0.13 to 6 mm² (26 to 10 AWG) and a maximum wire feed rate of 8 m/s. It needs a 400/230 V, 50/60 Hz, 16 A supply and 6 bar non-oiled, dried and filtered compressed air. [3]

Its crimping stations come with integrated crimp force monitoring, and one version adds electronic crimp height control; other stations load seals, twist and tin, or strip coaxial cable. The datasheet warns that wires with hard or tightly bonded insulation might not process even inside the stated range, and requires sample processing for cross sections smaller than 0.22 mm² (24 AWG) or larger than 4 mm² (12 AWG). The machine weighs about 440 kg without stations and about 750 kg fully equipped. [3]

Editorial note: send wire samples at the smallest and largest sizes on your wire list, including any hard or bonded insulation, with the quotation request. Ask whether crimp force monitoring and crimp height control are included on every crimping station quoted, and for the rate at your shortest cut length rather than the maximum feed rate.

05

Check what crimp force monitoring will and will not catch

Crimp force monitoring compares each press stroke's force curve with a recorded good reference. Researchers at Friedrich-Alexander-Universität Erlangen-Nürnberg published 2,439 labelled force curves from a semi-automatic bench crimper fitted with a strain sensor on the press connecting rod, recorded at 3,566 points per curve, crimping 0.50 mm² 16-strand and 0.35 mm² 12-strand FLRY-B copper wire into MLK 1.2 terminals with quick-change tooling. Good samples were stripped to 4 mm; defects were made by removing one, two or three strands or by stripping to 3 mm so insulation was crimped. [4]

The authors note that certain standards permit up to 10% of strands to be missing, so a monitor may legitimately pass a crimp with one strand gone. [4] Editorial calculation: one strand of 12 is 8.3% and one of 16 is 6.25%, both inside that 10% allowance, which fits the single-missing-strand class accounting for 123 of the 200 disagreements; and 20 kN is about 2.0 tonnes-force, against the 1.5-ton capacity in the cut-strip-crimp example above. [4] [2] Ask a machine supplier which defect classes its monitor was validated on, at which wire sizes, and to show the reject rate on deliberately faulty samples, then confirm with NASA-style pull tests. [1]

06

Wire feed, stripper, crimp press, error detectors and pull tester

Each machine part below maps to a line of the HC-10 example: ±0.002 × L cutting, 0.1–10 mm stripping, a 1.5-ton press and five error detectors. [2]

07

Crimp force, cycle rate, wire range and air supply for a harness crimper

Values here come from the HC-10 table, with two editorial conversions: 1.5 t is about 14.7 kN, and 4,000 pieces per hour is about 67 per minute. Pull-test strength is set by NASA-STD-8739.4A, not by the machine. [2] [1]

08

Send the wire, terminal and quality data together

Paste it into your enquiry below or into an email to a maker, then replace every bracket.

Wire: [types; cross-sections; insulation]
Terminals: [part numbers; seals; applicators]
Process: [cut length; strip length; one or two ends]
Output: [pieces per shift; changeovers]
Quality: [crimp monitoring; pull test; micrograph; traceability]
Site: [power; compressed air; floor space]

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