Aluminum CNC Machined Encoder End Cover Housing with 0.01mm Sealing Face Flatness and Leak Tested O Ring Groove ±0.02mm for Robot Joints

Encoder End Cover · O-Ring Groove · Leak Tested

The end cover is the part that looks simplest but has the highest rework rate: a 0.03 mm deviation in O-ring groove depth causes oil seepage, a 0.02 mm warp in the sealing face causes air leakage, and a thin-wall cover clamped too hard turns into a bowl shape. We machine the O-ring groove and sealing face in a single turn-mill setup, run pressure-hold leak tests on every batch, and ship with test records — so you don't discover leaks on your assembly line.

• O-Ring Groove Dimensions — The combination of groove width, depth, and bottom diameter determines compression ratio. We calculate per ISO 3601 and the customer's actual O-ring cross-section, with groove depth tolerance ±0.02 mm and groove bottom Ra 0.8.
• Sealing Face Flatness — Only within 0.01 mm can the O-ring compress evenly. Thin-wall covers must be measured in a free state; flatness measured while clamped in a fixture is not real.
• Thin-Wall Deformation — Cover wall thickness is 2–3 mm; slightly excessive clamping force turns it into a bowl shape. We use turn-mill single-setup machining to reduce clamping cycles, plus soft jaws with low-pressure clamping.
• Coaxiality and Threads — End cover to bearing seat coaxiality 0.02 mm, otherwise encoder air gap becomes uneven and signal jitters. Fastening threads must be coaxial with the spigot to avoid tilting the cover during assembly.
• Leak Verification — Each batch is sampled for pressure-hold testing (0.3 MPa / 60 s, leakage ≤ 0.05 mL/min), with records shipped alongside — customers don't need to perform their own first-article seal verification.

End cover dimensions are almost entirely determined by the joint's internal structure — standard parts rarely fit well.

• Sealing Solutions — O-ring, oil seal, labyrinth groove, or dispensed sealant, selected per IP rating and grease type.
• Encoder Adaptation — Incremental/absolute, magnetic/optical, with clearance cavities and read windows machined per model.
• Wiring & Connectors — Reserved aviation connector mounting holes, harness notches, and strain relief structures.
• Material Switching — Aluminum for weight reduction, stainless steel for corrosion resistance, POM for insulation; aluminum + POM hybrid covers available.
• Verification Support — Pressure-hold records and dimensional reports provided; re-testing after thermal cycling available on request.

The drawings of a humanoid robot's complete unit are often the core competitiveness of the next-generation model. We apply both physical and data isolation per project.

• NDA First — Bilateral confidentiality and non-circumvention agreements signed before receiving drawings.
• Dedicated Secure Area — Dedicated machines and personnel; no photography, no mobile phones allowed inside.
• No Display — Drawings, part photos, and customer logos never enter sample cabinets, catalogs, websites, or social media.
• Data Isolation — Programs and models stored on permission-controlled servers; destroyed with records upon project completion.
• Code Naming — Traveler cards and packaging labels use internal codes instead of customer part numbers.

Dongguan Changxinda Precision Technology Co., Ltd. was founded in 2008, with 90–102 employees, serving 200+ customers, export share 50–60%, annual sales of USD 10–20 million, ISO 9001:2015 certified.

The difference in sealing parts is not the equipment — it's whether a company is willing to build a pressure-hold station for a small part. We put it inside the process, not outside final inspection, because once oil leaks onto the customer's assembly line, rework costs are dozens of times the part price.

• Capacity Reservation — Production projects lock machines weekly; rush orders do not displace batch schedules.
• Two Shifts, Six Days — Production 07:30–22:00; weekend shifts added during peak season.
• Buffer Stock — Semi-finished stock kept for common specifications; repeat order lead time can be compressed by ~30%.
• Transparent Progress — Weekly progress reports + on-site photos; tracking number provided upon shipment.
• Shipping — Samples by express 3–5 days; batches by air/sea; EXW / FOB Shenzhen / CIF.

Dongguan Changxinda Precision Technology Co., Ltd. · Since 2008 · ISO 9001:2015

Keywords: cnc machining parts, robot joint encoder end cover, O-ring groove ±0.02mm, sealing face flatness 0.01mm, pressure-hold leak test