What gets marked on wiper motors
A wiper motor is a DC motor with a worm gearbox. It usually has a die-cast aluminium gearbox housing and a steel motor can, with a plastic gearbox cover that carries the moulded connector. Marking normally covers the vehicle maker's part number, the supplier's part number, a date code and a 2D Data Matrix code (DMC) that links the unit to its end-of-line test results such as current draw and park position.
Wiper motors sit in the cowl area below the windscreen, where rain water and engine bay heat both reach them. Labels have long been the usual way to carry the part number, but in that position they can lift at the edges, and a motor returned with an unreadable label cannot be traced. That is the main reason suppliers move to direct marking on the housing.
Front and rear wiper motors, and versions built for different linkages or vehicle models, can look almost identical. A clear model code on a visible face stops the wrong variant reaching the vehicle line.
Which laser marking machine suits wiper motors
The die-cast aluminium gearbox housing is the best surface for the main mark. For laser marking on wiper motors, a fiber laser on a smooth or machined die-cast face gives a clear engraved serial and a readable DMC. Where the casting is rough, use a flat pad near the output shaft boss or a spot-faced area.
Gearbox covers are typically glass-filled PBT or nylon, often black. Many of these grades mark with a fiber laser to a light grey, and grades made with a laser additive give stronger contrast. If your cover grade foams or gives a weak mark under fiber, a UV laser (355 nm) marks it with less heat and finer detail.
The steel motor can is usually e-coated or painted black. A fiber laser removes the coat to show bright steel, which suits a secondary serial on the can.
When a printed label still makes sense
Some vehicle makers specify a printed label in their own barcode format for receiving and service. A print-and-apply labeller is the practical tool for that, with a laser DMC on the housing as the permanent backup if the label is damaged.
Setting up the job
Pick one face for laser marking on wiper motors and build the nest around it, usually locating on the gearbox housing's mounting bolt holes so the mark lands in the same place on every unit. Keep the output shaft and crank arm out of the beam path, and check the head clears the connector shroud.
On an assembly line, marking normally comes after the end-of-line test, so only passed motors receive a serial. The marking PC writes the serial and test result to the line database, and a fixed reader checks the DMC before the motor goes to packing.
Die-cast housings from different cavities of the same die can differ slightly in surface texture. Grade codes from each cavity to ISO/IEC 29158, and keep a parameter set per housing type. Some vehicle makers still require their own barcode label. In that case a print-and-apply labeller handles the label, and the laser DMC on the housing stays as the permanent record.
What to check before you buy
- Mark surface. Decide whether the main mark goes on the die-cast housing or the plastic cover, and send samples of that part.
- Cover resin. Get the exact grade of the gearbox cover from your moulder and trial it on both fiber and UV.
- Label policy. Confirm with your customer whether the laser mark replaces the label or sits alongside it.
- Variant control. Check the software selects the job from the variant code so front and rear versions, or linkage variants, are never mixed.
- Test station link. Make sure the marker can receive pass or fail status from the end-of-line tester before it marks.
- Cycle time. Time a full mark plus reader check against the assembly line takt.
- Cavity variation. Trial housings from every die cavity, not only one sample.
- Extraction. Marking plastic and coated steel gives off fumes, so plan an extractor at the station.
Laser marking on wiper motors in Tamil Nadu
Wiper systems in Tamil Nadu go mainly to the car plants in the Sriperumbudur and Oragadam belt west of Chennai and to commercial vehicle plants around Hosur. Chennai's Ambattur and Guindy industrial estates host many die-casting job shops that make housings for auto component suppliers.
NMB Enterprises is based at Poonamallee in Chennai. Motor and wiper system suppliers can call or WhatsApp 098417 60722 with photos of the housing and cover and the resin grade, and get a recommendation for laser marking on wiper motors at their assembly line.