A second armature line for a power-tool motor plant in northern Vietnam

The customer builds universal motors for a European power-tool brand at a plant in Bac Ninh province. Their first armature line was assembled from second-hand machines over several years and depended on six operators per shift.

Volume for the 900 W family was committed to rise by roughly 60%, and the plant had floor space for one more line but not for six more operators.

Commutator runout was the plant's recurring complaint: the existing turning station held roughly 0.03 mm, and brush-life returns from the brand's service network were traced back to it.

First-pass yield at final electrical test sat at 94.2%, and most rejects were found only at the end of the line, after the winding copper had already been spent.

The new line had to run the same pallets as the existing conveyor so the two lines could share the downstream balancing and varnishing cells.

Nine stations were supplied: shaft, end plate and commutator pressing, slot paper, four-station winding, combined welding and testing, slot wedging, three-servo commutator turning and in-line final test, linked by a pallet conveyor matched to the customer's existing pallet.

Moving the electrical check into the welding station was the design decision that mattered: a bad joint is now caught immediately after welding rather than at the end of the line.

Factory acceptance ran at Bocadar in Dongguan on 500 of the customer's own cores, commutators and wire, recorded on video. Two engineers travelled for installation and site acceptance; commissioning and operator training took nine days.

From drawing approval to signed site acceptance: eleven weeks.

First-pass yield at final electrical test: 94.2% before, 98.7% over the first three months of production after.

Commutator runout measured between centres: 0.03 mm typical before, 0.008 mm typical after.

Operators per shift on the armature line: six before, two after.

Line takt: 12 seconds, giving about 300 armatures per hour.