Arm joint housings are large with generous stock, so there is room for error. Neck parts are the exact opposite.

• Perpendicularity of the two axes — the yaw bearing seat axis must be perpendicular to the pitch trunnion bore within 0.01 mm. Two setups cannot hold that, so both hole sets are machined in one clamping from a single datum, with perpendicularity coming from machine rotary accuracy.
• 3 mm thin wall with small footprint — clamping force scales with part size, and a standard vise distorts these parts on contact. Dedicated soft jaws plus internal support keep clamping force at the 0.3 MPa level.
• Dense harness — camera FPC, microphone and IMU ribbons total 3-5 bundles; the smallest wire path radius is R2 and polished, otherwise repeated threading during assembly scratches the FPC.
• The Cosmetic Face Is the A-Face — the neck is the most visible part of a humanoid robot, where tool marks, step-over lines and anodizing color shifts are magnified; cosmetic faces get their own finishing operation and dedicated toolpath instead of being hidden by extra polishing.
• Weight and Center of Gravity — the whole head mass is carried by the neck assembly; every 10 g removed lowers the holding torque needed from the pitch motor.

Head styling differs most between makers, so neck parts are almost always custom.

• Axial layout — yaw below pitch or serial double yaw, with bearing seat positions adjusted to your kinematics.
• Bearing and motor matching — crossed roller, thin-section or harmonic bearings and frameless torque motors, with bore and shoulder customized to the selection.
• Harness and Heat Dissipation — wire channel sized to camera FPC width and IMU position, with cooling fins or thermal pad grooves integrated where needed.
• Cosmetic Customization — blasting grit, anodizing color (black/grey/silver) and A-face tool mark direction can match your industrial design.
• Fast iteration in small batches — start from one piece, iterate 2-3 rounds with the head design, drawing revisions fully traceable.

The drawings of a complete humanoid robot are often the core competitiveness of the next machine generation. We apply both physical and data isolation on a per-project basis.

• NDA First — mutual NDA and non-circumvention agreement signed before drawings are received.
• Isolated Secure Area — dedicated machines and staff, no photography and no phones inside the area.
• Not displayed — drawings, part photos and customer logos never enter sample cabinets, catalogs, the website or social media.
• Data Isolation — programs and models sit on an access-controlled server, destroyed at project end with a written record.
• Code-named — traveler cards and packaging labels use internal codes instead of customer part numbers.
• A-Face Sample Control — cosmetic samples are individually numbered and logged, and never enter any display setting.

Dongguan Changxinda Precision Technology Co., Ltd.Founded in 2008, with a team of 90-102 staff, serving 200+ Customers, export share 50-60%, annual sales of USD 10-20 million, ISO 9001:2015 certified.

Small parts are hard in the fixturing, not in the machine: on the same machine, a little more clamping force makes the bore oval, and a slightly wrong toolpath direction leaves a step-over mark. That is why neck and wrist parts get dedicated fixtures and fixed toolpaths instead of being dialled in by hand every batch.

• Reserved Capacity — machine time is locked weekly for volume programs, so rush orders never displace batch schedules.
• Two shifts, six days a week — production runs 07:30-22:00, with weekend shifts added in peak season.
• Buffer Stock — semi-finished stock is held for repeat specifications, cutting repeat order lead time by about 30%.
• Visible Progress — weekly progress sheet plus shop floor photos, tracking number issued at shipment.
• Shipping — samples by express in 3-5 days, volume by air or sea, EXW / FOB Shenzhen / CIF.