Structure & materials

Load-bearing frames and housings support the system and protect its components. Material choice depends on geometry, loads and manufacturing.

Architecture, materials & specificationsArchitecture options, material requirements and integration constraints

Architecture options

Shape, wall thickness, connections and load conditions determine finished-part performance alongside the material.

ApproachMechanismAdvantagesTrade-offs
Aluminium alloysMachined, cast or extruded parts form frames, links and housings.Low density and practical machining suit lightweight structures.Thin sections can flex; threads, bearing seats and repeated loads constrain strength and fatigue life.
SteelsMachined or formed parts carry concentrated loads and resist wear.High stiffness and heat-treatable grades suit shafts and loaded interfaces.Greater density raises mass; corrosion protection may be needed.
Fibre compositesReinforcing fibres carry load within a resin matrix.High stiffness for their mass along the designed fibre directions.Holes, joints, off-axis loads and impact damage can govern the part’s performance.
Engineering polymersMoulded or machined polymers form covers, guides and selected structural parts.Low mass and complex shapes can reduce part count.Heat, moisture and gradual deformation under sustained load limit use.

Specifications & operating limits

Link performance combines mass, stiffness and fatigue life. Density helps estimate weight; elastic modulus describes the material’s resistance to stretching; yield strength marks the onset of permanent deformation. Section geometry sets bending stiffness alongside material properties.

Manufacturing & joints

Alloy, shape & process
Alloy and heat treatment set aluminium strength. Machining suits precise interfaces; casting can combine features but usually needs tooling and local finishing. Extrusion produces a constant cross-section. Bearing bores and joint mounting faces still need controlled dimensions, whichever process forms the body.
Composite layups & joints
Fibre direction determines where a composite is stiff. Inserts, bonded fittings or local reinforcement transfer concentrated loads at the tube ends. Holes interrupt fibres, and a joint can fail before the undrilled material reaches its quoted strength.
Fits across temperature
An aluminium housing expands more than a steel bearing ring for the same temperature rise. The fit can loosen, allowing the ring to move and wear its seat. Retention, tolerances and the temperatures of both parts determine the operating fit; a tight fit when cold may change in use.
Covers, access & repair
A protective outer cover has different requirements from a precision bearing housing. Polymers can suit low-mass covers and cable guides, while stiffness and creep constrain loaded mounts. Removable panels help service access, but openings, fasteners and seals also affect protection and cooling.

Dependencies & engineering limits

Limb mass & actuator load
Material added far from a joint increases the effort to hold and accelerate that limb. Weight saved at the hand or foot can therefore affect requirements farther up the limb.
Integrated actuators
Interfaces & alignment
Bearing seats and joint mounting surfaces need controlled dimensions. A lightweight frame that flexes at those interfaces can compromise the motor, transmission and encoder together.
Bearings
Housing & heat rejection
A housing may also serve as the motor’s heat sink. Thermal contact, exposed area and airflow affect how much heat it can reject. Adding an outer cover or enclosing the joint changes that path, so continuous torque depends on the assembled robot’s thermal conditions.
Frameless motors
Routing & service access
Cable bends, twisting motion and connector access take space inside links and housings. Joint travel can stretch or rub a harness that fits at rest; strain relief and routing control those loads.

Manufacturing & assembly

Guide

About this route

The route shows one process or architecture. Select a step to see its function and connections; related parts can be parallel inputs or alternatives.

Function

Inputs & dependencies
Outputs & connections
Related processes & parts
Sources

Manufacturing · Representative route. Tooling shapes the stock before thermal processing and final machining.

Related parts & processes 4

Aluminium billet

Extrusion starts with a heated aluminium-alloy billet.

Alloy and temper remain separate from the profile’s final geometry.

Sources & technical scope

Illustrative images of generic materials and components.

Related references
Link to this detail

Production equipment

Market context

MEVIUS2 · fabrication and hardware cost

US$6,150Metal parts · research build
US$12,905Total hardware · including metal parts

One research build’s procurement budget, including motors and sensors.

Lens Technology

10,000Rover X1 robots · assembly order

Complete-machine assembly order for Rover X1.

Xingyuan

Xingyuan Zhuomei reported RMB3.406 million in robot lightweight-component revenue in H1 2026. The robot-parts programme spans customer qualification, samples and small-batch production, including collaborative-robot applications.

Unitree

Unitree assembles robots and core modules internally. It buys custom mechanical parts and outsources most PCB assembly, injection moulding and some machining.

Explore documented supply relationships →