We machine stator and rotor housings, lamination stacks, shafts and fixture plates for electric motor builds. Tolerance held to ±0.005 mm, 100% inspection before shipment, and DFM feedback inside 12 hours.
Most stator and rotor problems are not electrical. They are dimensional, and they show up after assembly.
Lamination stacks clamped on a flat plate get compressed unevenly. Stack height moves 0.05 mm between the first and last part, rotor-to-stator air gap changes, and the motor runs hotter or noisier than the prototype.
When the housing bore and the shaft bore are cut in two setups, the centerline shifts. Bearing preload changes, the rotor drags, and you find out at end-of-line testing rather than at the machine.
Silicon steel at 0.20–0.35 mm thickness deforms under clamping pressure. Burrs bridge adjacent laminations, eddy currents rise, and the core loses more energy than the thermal model predicted.
The first ten parts come off a freshly trammed machine. By part 500 the fixture has worn, the deburr station has drifted, and the same drawing now produces parts that fail the go/no-go gauge.
Motor cores live or die on concentricity, stack height and surface condition. We plan the process around those three.
Housing bores, mounting faces and dowel holes come off a simultaneous 5-axis center in one setup. That removes the re-fixturing error that normally shows up as a shifted centerline between the bearing bore and the stator seat.
We check the bore with an air gauge or a CMM and record the roundness and cylindricity numbers. If the drawing calls for a fit that a reamed bore cannot hold, we bore and hone instead of reaming.
Silicon steel laminations and thin-wall aluminium housings move when you clamp them. We use soft jaws, expanding mandrels and dedicated fixtures that spread clamping force over a large area instead of a few points.
For laminated cores we control stack height with a pre-load step and verify it after clamping, so the number on the inspection sheet matches the number in the motor. Deburring is done by hand on the stack edges where a tumbler would round the lamination corners.
Use this to decide what to quote. It is the same table our process engineers use at review.
| Part | Recommended process | Why |
|---|---|---|
| Housing bore, Ø80–400 mm | 5-axis mill + hone | Holds roundness and centerline in one setup |
| Rotor shaft, Ø10–120 mm | Mill-turn center | Turns and mills keyways without re-chucking |
| Lamination stack, 0.2–0.5 mm sheet | Fixture + grind flat | Controls stack height and burr height |
| End plate, thin wall | 3-axis with vacuum plate | Avoids clamp distortion on 2 mm walls |
| Prototype end bell | 3D printing, then CNC | Fast geometry check before metal |
| Production end bell | Die casting + CNC finish | Lower cost per part above 1,000 pieces |
One shop for the metal parts around the stator and rotor, from a single prototype to a 10,000 part run.
Simultaneous 5-axis work on housings, end bells and stator seats. 16 centers available, up to 4,000 mm travel on the large machines.
Mill-turn centers for rotor shafts with keyways, threads and bearing journals cut without moving the part between operations.
Printed or machined prototypes for fit checks and early motor builds. Useful before the lamination die is committed.
Aluminium housings and end bells cast to near net shape, then CNC finished on the critical bores and faces.
Anodizing, electroless nickel, powder coating and bead blasting. Conductive anodizing is available for grounding paths.
Fixture plates, brackets and mounting hardware for motor test stands and production assembly stations.
| Item | Range |
|---|---|
| Tolerance | ±0.005 mm on critical fits |
| Surface finish | Ra 0.2–0.8 μm fine, Ra 0.8–1.6 μm standard |
| Maximum part size | 4,000 mm, largest machine travel 4,000 × 400 × 150 mm |
| Rotary table | Ø400 mm for circular features |
| Aluminium | 6061, 6061-T6, 2024, 5052, 5083, 6063, 6082, 7075, ADC12 |
| Stainless | 303, 304, 316, 316L, 420, 430, 440C, 17-4PH |
| Steel | 1018, 1045, 4130, 4140, 4340, A36, tool steel |
| Copper and brass | C101, C110, beryllium copper, C36000 |
| Plastics | ABS, PC, POM, PA, PEEK, PP, HDPE |
| Minimum order | One part, no minimum order quantity |
GreatLight has run precision machining out of Dongguan since 2011. These are the figures that decide whether your part ships on time.
Founded in 2011, three wholly-owned plants, 7,600 m² of floor space and 150 technicians on the shop floor.
16 simultaneous 5-axis centers, 12 four-axis mills, 27 three-axis machines and 16 mill-turn centers under one roof.
±0.005 mm (0.0002 in) on the fits that matter, with CMM reports available on request.
Send a drawing or STEP file and get a quotation plus free DFM analysis within 12 hours. Production can start inside 24 hours.
Standard turnaround after drawing release. Historical late-delivery probability stays below 2%.
From a single prototype to a 10,000+ part run on the same process plan. No tooling charge to start.
IATF 16949:2016 process control for traction motor housings and end bells.
Stator housings for servo and stepper motors where bore concentricity drives torque ripple.
Large motor frames and mounting plates up to 4,000 mm, machined on the long-travel centers.
Prototype rotor and stator hardware for drivetrain development, from one part upward.
We machine the metal parts around the magnetic circuit: housings, end bells, shafts, end plates, fixture plates and mounting hardware.
Lamination stamping and winding are not done in-house. We regularly machine the stack fixture and the housing that the wound stator drops into, and we can quote the stack machining if you supply the laminations.
±0.005 mm (0.0002 in) on critical fits, with the bore and the mounting face cut in one five-axis setup.
If your drawing calls for a tighter fit than a reamed bore can hold, we bore and hone. Send the fit class and we will tell you which route we would take before quoting.
Clamping pressure is the main cause. We use soft jaws and expanding mandrels so the force spreads over the circumference instead of a few contact points.
Deburring on lamination edges is done by hand. Tumbling is only used where it will not round the corners that stack against the next lamination.
Aluminium 6061, 6061-T6, 2024, 5052, 5083, 6063, 6082, 7075 and ADC12 for housings and end bells.
Stainless 303, 304, 316, 316L, 420, 430, 440C and 17-4PH for shafts and corrosion-resistant hardware. Copper and brass grades C101, C110 and C36000 for busbars and terminals.
Yes. Uploads are kept secure and confidential, and we can sign your NDA or provide ours before any file transfer.
Our non-disclosure agreement is available on request. If your motor program is under a development embargo, tell us at the quote stage and we will restrict who sees the files.
Quotation and DFM analysis come back within 12 hours of receiving a clear drawing or STEP file. Production can start within 24 hours.
Standard parts ship in 3–5 days after drawing release. If you need a housing and an end bell together, send both drawings in one request so they are planned as a set.
Every shipment is 100% inspected before it leaves. Incoming material is checked, dimensions are monitored in process, and the final inspection is recorded.
Reports are provided on request. If your quality group needs first-article inspection or CMM data on specific features, name those features on the drawing or the purchase order.
No. We run from a single prototype to 10,000+ part runs on the same process plan.
For quantities above roughly 1,000 pieces, die casting plus CNC finishing usually costs less per part than machining from solid. We will say so if that is the case for your part.
Upload a drawing or STEP file and get a quotation with DFM feedback inside 12 hours. No minimum order quantity, 100% inspection before shipment.
12-hour quote100% inspectionNo MOQNDA on request
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Upload your 3D model or 2D drawing and get a quotation with a free DFM analysis. Maximum processing size 4,000 mm.
CNC Metals 13 grades
CNC Plastics 10 grades
Machines & processes 12 options
Surface & post-processing 10 options
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