By TEBAOFLEX Jyen. Originally published on January 5, 2026.
Robot dress-pack cables can experience twisting, bending and tension at the same time. A cable qualified for a linear energy chain is not automatically qualified for a robot wrist. The selection basis is the measured motion of the complete route and the supplier’s test conditions for the exact cable.
Understand degrees per metre
A torsion figure such as ±360 degrees per metre describes twist relative to a free length under specified conditions. It is not permission to rotate every short section through ±360 degrees. For illustration, a uniformly distributed 180-degree rotation over 0.5 m corresponds to 360 degrees/m; over 1 m it corresponds to 180 degrees/m.
Real dress packs do not necessarily distribute twist uniformly. Clamps, conduit friction, bends and contact with adjacent services can concentrate it. The cable and robot suppliers should define free lengths, clamp positions and the allowed rotation in both directions.
Screen construction must match the duty
Spiral screens and specially designed braids are possible approaches. A conventional braid may not tolerate a particular twisting duty, but it is incorrect to say all braids are unsuitable for robotics. For example, igus describes a torsion-resistant tinned-copper braid in its CFROBOT2 construction. That is a manufacturer-specific example, not a TEBAOFLEX rating.
Screen continuity, transfer impedance and termination must remain suitable throughout the intended motion. Initial optical coverage does not establish long-term EMC performance, and a screen description alone cannot predict cycle life.
Compare test conditions, not headline cycle counts
- Twist angle in both directions and free specimen length.
- Bend radius and whether bending occurs simultaneously with torsion.
- Axial load, speed, cycle definition, temperature and environmental exposure.
- Acceptance criteria for conductor and screen continuity, insulation and jacket condition.
- Whether the tested construction and termination match the offered assembly.
A five-million-cycle torsion test and a ten-million-cycle planar bending test are not directly comparable. Conductor class, fine strands and sliding layers are design features; none independently guarantees an operating life.
Hybrid cables and welding environments
Combining power, brake, feedback and communication circuits can simplify routing, but requires correct electrical separation, signal properties and terminations. The selected protocols must be supported by the actual cable construction and connectors; a list of bus names is not interoperability evidence.
Oil, coolant, hydrolysis, abrasion and weld-spatter resistance are separate requirements. A PUR or TMPU designation does not prove cross-linking or immunity to hot slag. Obtain application-specific test evidence and use protective routing where the robot manufacturer requires it.
Cleanroom suitability is a different qualification
ISO 14644-1 classifies air cleanliness by particle concentration. It does not award a cable a universal zero-particle or zero-outgassing rating. For a cleanroom robot, request a suitability report identifying the cable, movement, temperature and sampling conditions, then assess the complete dress pack and cleaning procedure.
Installation and maintenance
Pay off cable without introducing unintended twist, follow the approved clamping and strain-relief drawing, and verify the full motion envelope at commissioning. Record rubbing, changes in cable shape and connector stress. Set inspection and replacement criteria from the robot and cable documentation rather than an unsupported universal free-span or cycle rule.
Sources and application documentation
Discuss the application
Send the application duty, installation drawing and required acceptance criteria to TEBAOFLEX. WhatsApp: +86 185 9591 3361. Request the applicable product documentation before ordering.