Mechanical Response: The carriage rail system must maintain a displacement error of less than 0.3 mm under a load of 60–90 kg to ensure the movement path remains true and to prevent compensatory muscle engagement; spring resistance must exhibit linear characteristics and support precise adjustment across 1–5 levels (ranging from light assistance to high-intensity resistance).
Structural Load-Bearing: Commercial-grade frames must support a load of ≥450 kg, while home-grade frames must support ≥300 kg; aluminum alloy components (6061/6063 grades) must balance flexural rigidity with lightweight design, while solid wood or steel structures must ensure that mortise-and-tenon joints or welded connections remain secure and free from looseness or abnormal noise.
Safe Interaction: The leather surface must provide a slip-resistant coefficient suitable for bare feet or anti-slip socks; edges must be beveled to prevent injury from bumps; and the folding mechanism must feature a self-locking function to prevent accidental closure.
Durability and Longevity: Springs must withstand 100,000 to 2,000,000 cycles of tensile fatigue testing without deformation; pulleys and sliders must be wear-resistant, ensuring smooth operation without sticking or binding during long-term use.
