An energy chain (cable carrier) is one of the most important — and most overlooked — components in automated machinery. It guides and protects cables, hoses and tubing as they flex with the moving axis, and a poorly selected chain is a leading cause of premature cable failure and machine downtime. This guide walks through the igus e-chain selection process in the order the numbers matter.
1. Confirm the Movement Type
Energy chains are designed for specific motions. Most applications are linear travel (a carriage moving along a fixed axis) but some need rotary or vertical chains. Confirm the axis and the travel length first — the chain length, mounting and number of links all follow from it.
2. Determine the Required Inner Height
The inner height (Hi) must accommodate the largest cable or hose plus sufficient clearance:
- Measure the diameter of the thickest cable/hose you will route.
- Add at least 10% clearance (for hose versions, more — hoses can swell under pressure).
- If cables stack in more than one layer, account for the total stack height.
Choosing an inner height that is too small crushes cables over time; too large wastes space and adds weight and cost.
3. Select the Inner Width
The inner width (Bi) is determined by how the cables are arranged side by side. Lay the cables out (with clearance between them), measure the total width, and select the next standard width up. igus e-chain inner widths typically range from about 6 mm up to several hundred millimetres.
4. Choose the Bend Radius
This is the most critical selection: the bend radius (R) of the chain must be equal to or larger than the minimum bending radius of the stiffest cable inside it. Check the cable datasheet — for chainflex cables the minimum bending radius is printed for each series. If in doubt, go one size larger; an undersized radius destroys cables.
As an example, the igus E2.17.015.028.0 is an E2.17 chain with 15 mm inner width and 28 mm bend radius — suitable for small control cables with a 28 mm or smaller minimum bending radius.
5. The e-chain Series: E2 vs E4
| Series | Positioning | Inner heights | Typical use |
|---|---|---|---|
| E2 series | General purpose, cost-effective | 17–80 mm typical | Standard machine axes, small-medium cables |
| E4 series | Heavy-duty, high loads | 80 mm and larger | Long travels, heavy hoses, high acceleration |
For most machine tools and handling systems, the E2 series covers the need at the best price; for long travels and heavy loads, step up to E4.
6. Combine with chainflex Cables for Predictable Life
Matching the energy chain with chainflex continuous-flex cables is the classic igus combination: chainflex cables are tested in igus chains with guaranteed bending radii and service life predictions. This removes the guesswork — the chain, the cables and the minimum radius are designed to work together, and pre-assembled readychain systems even cut assembly time by up to 95%.
7. Check Travel Length and Mounting
- Free travel (unsupported length) — the longer the free travel, the heavier the chain must be; check the unsupported length limits in the datasheet and consider glide or roll installations for very long travels.
- Mounting — confirm the chain ends (KMA mounting brackets) match your connection points on both the fixed and moving sides.
Buying Guide for Glorient Customers
Glorient supplies genuine igus e-chain energy chains and chainflex cables with competitive pricing and worldwide delivery. To select the right chain:
- Confirm your travel length, cable diameters and the minimum bending radius of the stiffest cable.
- Browse the energy chains & cables range for the matching series and size — e.g. the E2.17 for compact axes or the E4Q.82 for heavy-duty runs.
- Send your cable list and travel details via the quote request form — our engineers will confirm the chain size, radius and accessories within 24 hours.
Energy chain selection is a geometry exercise: height for the thickest cable, width for the arrangement, radius for the stiffest cable, and the series for the load. Get the radius right and the chain — and the cables inside it — will outlast the machine.
Frequently Asked Questions
How do I determine the bend radius of an energy chain?
The bend radius must be larger than the minimum bending radius of the largest cable or hose carried inside, typically 7.5 to 10 times the cable outer diameter. Choosing too tight a radius over-stresses the cable and shortens its life dramatically.
How do I size the inner height and width of an e-chain?
The inner height must exceed the largest cable diameter by at least 10-20 percent, and the total cable fill should stay below roughly 80 percent of the cross-section. Leave clearance so cables do not rub against the chain walls during flexing.
What is the difference between open and closed energy chains?
Open chains leave the cables visible and are easier to access for maintenance but exposed to debris. Closed (or tube) chains fully enclose the cables, protecting them from chips, coolant and dust - preferred in machining and woodworking environments.