Why a 2D carrier cannot follow a six-axis wrist
The links are designed to rotate about one axis. Applied torsion, the pin and bore are loaded in a direction they were never sized for, side plates spread, and the chain either binds or sheds links. No amount of extra support fixes a torsional load.
If the motion at the wrist genuinely needs three-dimensional freedom, the correct solution is a dress pack with torsion-rated cable, a cable retraction system, or a multi-axis rotating carrier. We do not make the latter, and we will tell you that at the enquiry stage rather than after delivery.
Where these carriers do belong
- 7th-axis linear tracks — Long travel, one plane, high duty — exactly what a plastic carrier is built for. This is the largest part of our robot-related business.
- Gantries and trusses — Two-axis Cartesian motion where the cable run stays in a single bending plane but the span is long.
- Robot cells and palletisers — Fixed-cell cable routing between controller cabinet and the cell, where the machine moves but the robot base does not.
- End-of-arm dressing, in one plane — Where the tooling only tilts about a single axis and the travel is short, a small micro carrier is often neater than a dress pack.
Cable choice matters more here than the chain
On a track the chain controls the bend radius, but the cable has to survive the cycles. Use cable rated for continuous flex at the radius you are actually running, and anchor it at both ends — one end fixed to the carriage, one to the frame — so the chain carries the loop and the cable does not.
A high-flex cable run at half its rated bend radius will fail before the carrier does, and the failure will be blamed on the carrier.
Common failures on robot installations
- Chain fitted to the wrist — Torsion failure. Not repairable by adding supports. Re-route instead.
- Cable not anchored at the moving end — The cable walks through the chain and pulls on the connector. Anchor it.
- Travel measured as stroke, not as chain length — Chain length is roughly half the travel plus the bend arc; underestimating it puts the fixed end in the wrong place and the chain runs out of links at end of stroke.
- Mixed carriers on one cell — Different materials wear at different rates and the ribbons interfere. Keep one family per cell where you can.
Specification at a glance
| Series | Micro / medium / heavy-duty |
|---|---|
| Inner height | 5–80 mm |
| Motion type | Single-plane bending (2D) |
| Typical use | 7th-axis track, gantry, robot cell |
| Material | PA66 + 30 % GF |
| Life test | ≥ 15 million cycles |
Figures are the range across the series, not a guaranteed value for every size. Confirm the model against your duty before ordering.
Questions buyers ask at this stage
Do you make cable carriers for six-axis robot wrists?+
No. Our carriers bend in one plane, and a wrist needs three-dimensional freedom. For that motion we recommend a dress pack or retraction system with torsion-rated cable.
How do I work out the chain length for a 7th-axis track?+
Roughly half the travel plus the bend arc length, rounded up to whole links, then confirmed against the mounting positions at both ends. Give us the stroke and the mounting height and we will do the arithmetic and send the drawing.
Can the same carrier run vertically on a lift axis?+
Yes, with the right frame size and a check on the hanging loop. Vertical runs need more care about cable weight and about the return loop resting on itself — send the layout.
Send the layout sketch
Stroke, mounting height, whether the run is horizontal or vertical, and the motion type. A hand sketch with dimensions is enough to tell you whether a carrier fits or whether you need a dress pack.