Electronic needle selection is what allows a knitting machine to produce a programmed pattern instead of a plain fabric. Each selector is a small solenoid that fires to take or skip a needle, thousands of times a minute, and every selector across the machine has to act at the same instant as the one beside it. WIRESUN has been winding needle selection solenoid coils for textile machinery at 3,000 turns of 0.125 mm wire, two coils per cycle on twin spindles. Production currently stands at 862 units with zero defects, which is just over 2.58 million turns wound without a single reject.
Video of Coil Winding for Textile Needle Selection Solenoids
High-frequency actuation. A needle selector fires thousands of times per minute for an entire production shift, so the coil has to deliver the same magnetic pull on the last cycle of the day as on the first, without drifting as it warms up.
Timing consistency across the machine. Selectors work as a set, not as individuals. A coil that responds even slightly slower than its neighbours mis-selects a needle, and the result appears as a visible line in the knitted fabric rather than as a failure on the test bench. This makes coil-to-coil uniformity, not single-unit conformance, the real acceptance criterion.
High turn count in a small envelope. Needle selection units sit side by side at close pitch, so the coil has to reach its required ampere-turns inside a very small bobbin. Here that means 3,000 turns of 0.125 mm wire, which leaves no room for untidy layering.
Tolerance of the textile environment. Knitting machinery runs in fibre dust and lubricant mist with constant vibration, so the winding, the lead terminations and the insulation system all have to survive conditions that would be considered dirty in most other industries.
Long service life under continuous production. Textile plants run three shifts, and a selector coil is expected to keep its electrical characteristics stable for years rather than months. Replacing one means stopping a machine, so reliability is measured in downtime avoided, not in parts supplied.
Winding Precautions
Wire Selection: At 0.125 mm the conductor is fine enough that enamel quality governs the outcome. The wire has to take handling and layering without pinholes in the insulation, because an inter-turn short in a 3,000-turn coil is not repairable.
Tension Control: Fine wire punishes error in both directions. Too much tension stretches or breaks the conductor and reduces its cross-section; too little produces loose, uneven layers that will not fit 3,000 turns into the available bobbin width. Tension is held constant for the whole run rather than merely set correctly at the start.
Turn Count Accuracy: At 3,000 turns, a single missed or extra turn shifts both resistance and inductance, and therefore the actuation timing of that selector. Turn count is verified rather than assumed, on every coil.
Winding Neatness: The wire arrangement must be neat and tight, with no crossing or overlapping. Crossovers waste bobbin width that a 3,000-turn coil does not have to spare, and they create local stress points where the enamel is most likely to fail.
Twin-Spindle Matching: Winding two coils per cycle is not only a throughput decision. Both coils come off the same setup, the same wire and the same tension profile, so they leave the machine already matched to each other rather than being matched afterwards by selection.
Lead Wire Securing: The lead terminations are the weak point on any fine-wire coil, and vibration is continuous in textile machinery. Leads are anchored so that machine movement is never carried into the winding itself.
Batch-Level Process Control: On a part where uniformity is the specification, a long unbroken run is the only meaningful proof of stability. A single good sample says nothing about the process. 862 units with no rejects says that the process, not the operator, is producing the result.
About WIRESUN
Founded by a management team with over 30 years of hands-on expertise in coil winding, WIRESUN has grown into one of Dongguan's trusted precision coil manufacturers. We provide OEM and ODM custom coil winding services, producing air core coils, bobbin coils, and special-shaped coils, along with coil winding machines and wire tensioners.
Contact us:
tech@wiresun.com ｜ +86-186 2185 7689 (Bi Danfeng)