Two bearing seats at opposite ends of a hollow body are the hardest pair of features in the part. Machine them in two setups and the second seat inherits the error of the first plus the re-clamping error — a 3 mm wall body deflects under the jaws, and the result is a pair of seats that look correct individually and fight each other in assembly.

We bore both seats on a single boring axis in one clamping, with a long boring bar and in-process probing, holding 0.008 mm coaxiality across the full length. The cable path is machined in the same setup, so the window and the seats share a datum instead of being reconciled afterwards.

• One boring axis — both H7 seats from one setup, 0.008 mm coaxiality, 0.006 mm roundness.
• Cable-first design — Ø45 bore and 32 x 18 window sized to 6-8 cables with bend radius allowance.
• No snag path — every internal edge broken to R3 and polished, borescope checked.
• Seal discipline — seal faces masked before anodizing and re-checked afterwards.

1. Harness and bore review — cable count, connector size and bend radius confirmed; bore, window and seat sizes agreed before machining.
2. Billet and material verification — 6061-T6 received by heat number, ultrasonic check, 3.1 certificate.
3. Rough turning and boring — OD, through bore and both seat ends roughed with 1.0 mm allowance, rotational datum established.
4. First stress relief — low-temperature stress relief before the wall is opened to 3.2 mm.
5. 5-axis milling — flange faces, bolt pattern, side window and mounting bosses machined in one clamping.
6. Second stress relief — a second cycle so the seat bores do not close up after finishing.
7. Line boring — both H7 seats bored and reamed on one axis with a long bar, in-process probed to 0.008 mm coaxiality.
8. Deburr and clean — internal channel deburred by hand and back-chamfer tool, ultrasonic cleaned, borescope inspected.
9. Surface and verification — masked anodizing, seal faces re-checked, CMM report with coaxiality data shipped with the part.

• Through bore — Ø30 to Ø60 mm, straight or stepped, with or without keyway.
• Windows — side window, end slot or split shell, sized to the connector.
• Seats — H7/G7, single or double row, with shoulder and spacer arrangement to match the bearing.
• Interfaces — flange bolt pattern M3-M10, dowel pins, ISO 9409 patterns on request.
• Sampling — 1 piece to prove the harness path, then volume on the same program.

A through-bore joint carries the cable layout of the whole arm, which is often more sensitive than the part itself. Access is limited accordingly.

• NDA first — mutual NDA and non-circumvention signed before drawings are transferred.
• Isolated cell — dedicated machines, authorized staff only, no photography or phones inside.
• Codified routing — internal codes replace your part number and project name on cards and labels.
• Data isolation — CAD and programs on a permission-controlled server, per-project folders, destruction on request with a record.
• Silent supply chain — subcontract stages see internal codes only, never the drawing title block or brand.

Dongguan Changxinda Precision Technology Co., Ltd. — founded in 2008, 90-102 staff, ISO 9001:2015 certified, annual sales USD 10-20 million, export share 50-60%, serving customers in Europe, North America, Japan and Southeast Asia.

Turning, milling, honing, stress relief, anodizing and CMM inspection are all in-house, which is what makes a long line-bored part repeatable: the datum never leaves the building. Equipment includes 5-axis and 4-axis machining centers, turn-mill centers, CNC lathes, deep-hole boring, surface grinders and wire EDM.

1. 01 Consumer Electronics — Phone, tablet and laptop housings · heat sinks · camera brackets · VR/AR headset structural parts · smart wearable housings
2. 02 Automation & Industrial Equipment — Automation jigs · fixtures · module frames · transmission sliders · motor mounts · sensor housings · conveyor line components
3. 03 Semiconductor & Vacuum Equipment — Vacuum chambers · vacuum fittings · semiconductor equipment precision bases · thermal insulation parts · inspection fixtures
4. 04 Medical Devices — Surgical instrument bases · medical device housings · endoscope components · aesthetic equipment structural parts (medical grade aluminum / stainless steel)
5. 05 Automotive — EV motor housings · battery end plates · sensor brackets · lamp structural parts · aftermarket parts · hydraulic valve blocks
6. 06 Aerospace & UAV — Aircraft structural parts · UAV frames · landing gear components · avionics instrument housings (lightweight precision parts)
7. 07 Optics & Photonics — Optical lens barrels · lens mounts · light source heat sinks · camera module brackets · inspection optical stages
8. 08 Telecommunications — 5G heat sink cavities · filter housings · signal adapter brackets · telecom equipment enclosures
9. 09 Robotics — Robotic arm joint parts · robot bases · reducer housings · AGV chassis structural parts
10. 10 Instruments & Meters — Inspection equipment housings · precision gauge bases · flow meter parts · laboratory equipment components

Two shifts 07:30-22:00, six days a week, with weekend shifts in peak season. Capacity is locked weekly for volume programs, so rush orders and batches are scheduled on separate lines.

• Samples — 7-10 days, with the harness path validated before the batch is released.
• Batch — 15-20 days from deposit and drawing approval.
• Buffer — semi-finished stock for repeat models, cutting repeat lead time by about 30%.
• Shipping — DHL/FedEx/UPS samples in 3-5 days; air or sea for volume; EXW Dongguan, FOB Shenzhen or CIF.
• Documents — FAI, 3.1 material certificate, CMM report and packing list with every shipment.

Send STEP / IGES / DWG / PDF and receive DFM feedback plus a formal quotation within 24 hours.

Dongguan Changxinda Precision Technology Co., Ltd. · ISO 9001:2015 · Dongguan, Guangdong, China