Hollow Robot Joint Housing 6061-T6 Seamless Tube Through Bore Cable Routing 0

What Makes a Hollow Housing Different

A hollow joint housing is not a solid housing with a hole added. Removing the core changes how the part behaves: the wall deflects under clamping, the bore chatters when a long tool reaches through, and heat from machining moves the tube between passes. This housing is therefore built from 6061-T6 seamless tube rather than a bored-out billet — the bore already exists, grain runs along the axis, and there is far less material to remove, which keeps residual stress low and the wall thickness even.

The through bore doubles as the cable route for the joint, so wiring, tubing and an encoder cable pass inside the structure instead of looping outside the arm. Twin end flanges bolt to the reducer on one side and the arm link on the other, with bearing lands machined inside each end.

How the Bore Is Held True

Deep boring in a thin tube is where most hollow housings lose tolerance. The route below is designed to stop the wall from moving while it is being cut.

Precision Capability

Where the drawing demands tighter coaxiality than the tube route can repeat, we say so at quotation and propose either a thicker wall section or a different process, rather than accept a tolerance the wall cannot support.

Non-Standard Hollow Housings

Every hollow housing here is made to a drawing. The working range below reflects what the lathes, mandrels and fixtures actually handle.

• Outer diameter 40-300 mm, bore 20-200 mm, length 50-600 mm
• Wall from 2 mm, with thicker bosses added locally for bearing lands and tapped holes
• Materials: 6061-T6, 6082-T6, 7075-T6, 2024-T351 seamless tube or billet, 304/316L stainless tube, titanium on request
• Features: cable exit windows, seal grooves, bearing lands, keyways, sensor pockets, encoder mounts, lifting lugs
• Single flange, twin flange, or flange plus threaded collar configurations
• Balancing, pressure tightness check or anodize masking quoted as options
• Input formats: STEP, IGES, X_T, STL, DXF, 2D drawing with GD&T, or a sample for scanning and rebuild

Confidentiality

Inside the Factory

Dongguan Changxinda Precision Technology Co., Ltd has machined custom parts since 2008. Equipment includes 4-axis and 5-axis machining centres, turn-mill combination lathes, CNC lathes and milling machines, backed by an ISO 9001:2015 quality system and an in-house CMM room. The plant supplies more than 200 customers in medical equipment, robotics, automotive, aerospace, automation, laser, LED, lithium battery and precision instruments, with 50-60% of output exported. Long-part turning, mandrel fixturing and thin-wall boring are routine work here, which is why hollow housings do not need to be outsourced to a specialist shop.

Delivery Discipline

• Monthly capacity near 10,000 pieces for this housing family
• Each part number allocated across two machining centres so one breakdown does not stop your order
• Programme, mandrel and inspection plan frozen after first article; repeat batches skip the ramp-up
• Buffer WIP held on running series orders for forecast changes
• Express, air and sea freight; EXW, FOB or CIF; long parts crated with internal supports to stop bending in transit
• Rush capacity for line-down situations, quoted with a date that can be met

Key Features

• 6061-T6 seamless tube stock with axial grain and concentric wall
• Through bore used as an internal cable route for the joint
• 0.01 mm flange-to-flange coaxiality, verified end to end
• Mandrel-supported boring to suppress chatter in thin sections
• Wall thickness scanned and reported at defined stations
• Bearing lands finished in the same pass as the main bore
• Radiused cable windows so no harness is chafed
• NDA-protected handling with project-code documentation

Typical Applications

• Robot shoulder and elbow joints with internal cable routing
• Collaborative robot arm links and hollow wrist housings
• Humanoid robot limb segments with wiring inside the structure
• Semiconductor handling robot arm tubes
• Medical and laboratory robot articulation sleeves
• Camera and sensor pan-tilt joint housings
• Automation rotary joints with through-wire requirement
• Exoskeleton and rehabilitation device structural tubes

FAQ

Q: Why use tube stock instead of machining from solid billet?
A: The bore already exists, grain runs along the axis, and far less material is removed, so stress and distortion stay low and wall thickness stays even. It also shortens cycle time on long parts.

Q: Will you sign an NDA before we send the assembly drawing?
A: A mutual NDA is signed first, covering drawings, models, scans and samples. The same terms apply to mandrel and fixture design work.

Q: How thin can the wall be?
A: 2 mm is workable in 6061-T6 for moderate lengths with mandrel support. Below that, we review length, cable window size and load case before quoting, and may propose local thickening.

Q: Can the bore be used for cable routing with sharp features removed?
A: Yes. Cable windows and internal transitions are radiused, edges broken inside the tube, and the bore finished to Ra 1.6 or better so a harness can be pulled through without damage.

Q: What is the minimum order?
A: One piece. No tooling charge and no programming fee, so a single hollow housing for a prototype build is a normal order.

Q: How do you prevent long hollow parts bending in transit?
A: Parts are crated horizontally with internal supports and foam cradles, and long sections are strapped to prevent whip during handling and sea freight.

Q: What do you need to quote?
A: 2D drawing with tolerances, 3D model, quantity, material, treatment and target date. Quote and DFM comments return within 24 hours.

Related Parts From The Same Plant

• Robot Joint Housing 6061 Aluminum Helical Weight Slots Turn-Mill Machined 0.006mm Concentricity
• Robot Joint Connecting Tube 6061-T6 Aluminum Alloy CNC Precision Machined 0.01mm
• Robot Gearbox Housing 7075-T6 Aluminum Matched Cover Pair Line Bored H7 Bearing Seats 0.005mm