Weighing Up The Options

According to Dietmar Grun at IMI Norgren, electric systems are not the all-embracing panacea that they are cracked up to be. Although he acknowledges that electricity is cheaper than compressed air, he says that manufacturers should not select an electric linear systems for this reason alone.

`There are plenty of hidden costs to the electrical option. Take energy, for example. A pneumatic cylinder will give far more force than an electrical cylinder of the same size. So immediately, there is a cost saving on the cost of the cylinder,’ he says.

Similarly, he adds, if you are using a substantial amount of compressed air in your operation, it makes sense to use that air instead of installing the infrastructure you will need to operate a linear servo system. Ease of installation and operation are two powerful factors in the favour of pneumatic systems. Operators require very little electrical know-how and programming is easy.

In addition, you can store energy remotely with a compressor, which an electric motor cannot do. This has additional safety benefit where the routing of high-powered electrical cables across a machine is involved. Physically, pneumatic systems have a far more compact envelope than their electric linear counterparts, because of the need to add a motor to the electrical system. Similarly, pneumatic systems have stroke lengths of up to 8500mm, while electric linear systems run to about 5000mm.