e-spool – the alternative to the cable drum on an indoor crane - igus Blog

e-spool – the alternative to the cable drum on an indoor crane

Jens Göbel | 21. April 2020

As already described in my blog post about cable guidance for load-carrying devices on indoor cranes, these sometimes need their own power and control system supply. In order to be able to perform the lifting movement of the load carrying device, the cables must either be wound onto a drum or, with the aid of an energy chain, safely stowed in a collecting basket.

However, there are a number of applications and load-carrying equipment designs that have no space for a collection basket. If you think that there is no way around a classic motor drum solution, you are wrong.

But before we turn to the appropriate solution with an energy chain, I would like to take a brief look at the motor cable drum.

Motor cable drum:

For maintenance, such a cable guidance means regular maintenance work, with the consequent downtime of the crane. But what are the components that require this kind of maintenance on a motor cable drum? On the one hand such a system includes a slip ring, on the other hand either a separate drive motor or a spring system. Both drive types are used to wind the cable up or down from the drum under a constant tensile strain. The tensile strain stresses the cable(s) used and therefore has a negative effect on the service life.


At first sight of the e-spool the question arises to what extent this component with energy chain differs from a motor cable drum and the extent of its maintenance. On the one hand, the e-spool uses an energy chain that absorbs all tensile strain. The guided cables are therefore not exposed to tensile strain, which has a positive effect on the service life of the cables. On the other hand the e-spool is completely free of slip ring. This eliminates a maintenance-intensive component. The e-spool can also be used to guide other media securely. In terms of cable diameter, the system is limited to outer diameters up to 17mm. Since no sliding contact is used in the e-spool, the cables or hoses are guided through the system without interruption. These can therefore be exchanged or changed at any time. What the e-spool and some motor cable drums have in common is the retracting spring. This component requires regular maintenance and has a limited service life. The retraction of the spring also limits the travel (chain extension) to a length of 14 metres. For those who prefer to do without the spring retraction or need a longer extension length, there is the e-spool power.

e-spool power:

The motor-driven e-spool is identical to the normal e-spool described above, except that this version is driven by a motor instead of a spring retraction. This, of course, includes all maintenance steps and intervals that are necessary for a trouble-free operation of the motor. The motor drive makes it possible to implement travels of up to 25 metres.


As with all energy chain applications, but especially with the e-spool, only cables that have also been developed for the energy chain should be used, for example chainflex. For e-spool applications we recommend the use of cables with a TPE outer jacket and for shielded cables even the use of twistable cables such as CFROBOT.

e-spool assembly


For assembly, cable installation in the e-spool chains and tightening of the spring, we have put together appropriate instructions in the form of videos on our website.

e-spool indoor crane steel mill

Application examples:

If we have aroused your interest with e-spool as a modern cable guide, and you would like to see where and how it has been used in other applications, then just take a look at our website. From stage technology and baling presses up to automation and vertical movements, there is something for everyone.

On our website you will find further examples and solutions for cable guidance on indoor cranes, as well as our brochure for free download.

Do you still have questions or an application you would like to discuss with us? Arrange a virtual consultation appointment now

You already voted!
You are also welcome to comment on the article - we look forward to your opinion!