When to turn to custom drive system design

When standard drive system parts can’t fulfil their destined application, it might be time to consider a customised alternative. Stewart Goulding, manging director of bespoke custom gearbox producer EMS, explains when custom design is the right choice for manufacturers.

Standard components are the first port of call for design engineers looking for a new drive system, as they are more readily available and generally have lower associated costs. For many applications, a standard component drive system will fulfil the application requirements, however, that’s not always the case and can result in an under or over engineered solution that is not fully optimised for the application.

When selecting standard components, you are limited to their conventional form. A common driver for taking a custom design route is limitations in space envelope, particularly in light of the constant miniaturisation and light-weighting trends currently seen in many industry sectors. More compact, agile robots, for example, are becoming commonplace in factories, laboratories and many other industries, so their drive systems must shrink to fit, but still offer the high power output required for the robot to function optimally.

As well as making drive systems smaller, custom design teams can alter the configuration of the drive orientation. For example, restrictions in space envelope may make it desirable for the output of the drive system to be reversed back in a U-shaped configuration, which can only be achieved with a custom design.

Many applications require drive systems that need to be optimised to reach a specific output performance or working point and provide unique integration characteristics so that the resulting product can not only achieve specific technical requirements but also simplifies the mechanical and electrical interfaces. In such cases, a customised drive system may be more applicable, as design engineers have the flexibility and control to specify the features required.

The EMS design team will design a custom drive system specifically for an application and can include features such as custom orientation, special shaft and mounting interface, overload clutch systems and special wiring looms to name but a few. Furthermore, the design engineers will optimise the material and gear type selection to optimise efficiency and noise levels to meet the exact requirements of the application.

When is a custom drive system viable?

Whenever an application cannot be fulfilled using standard platform products then a custom design should be considered. The benefits and opportunities that a custom drive system offers can be significant and will potentially provide you with a USP in your market and resulting competitive advantage. A commercial balance is always necessary to establish the viability of each project, whereby volume, price point and longevity versus design investment are key considerations, however the barrier to entry can be low and should be reviewed on a case-by-case basis.

Design choices and manufacturing techniques will be dictated to some extent by the potential volume required and each can be explored during the concept phase to satisfy application volumes starting in the low hundreds.

Zinc die casting is often used for higher volume applications to manufacture custom gearbox housings. Die casting involves forcing molten metal under high pressure into a mould cavity, producing high quality finished goods. The ease and high performance of this manufacturing technique along with the long tool life and precision gear design and assembly allows EMS to produce products with production runs exceeding 50,000 units per year.

Fully equipped machine workshops can now autonomously manufacture component parts. These automated production systems, in combination with skilled operators, create efficient and flexible production lines that minimise waste and maximise machine tool utilisation.

With an in-house design team and improvements in manufacturing processes, custom design solutions are accessible for more applications than ever before. At EMS, our custom drive systems are used in a broad spectrum of applications, including medical devices, assisted living, lab equipment, automotive and agricultural technology.

An off-the-shelf solution remains the simplest and easiest route to take, whether that’s buying a new suit or purchasing a drive system. However, where standard components cannot meet the application requirements, customised alternatives offer flexibility in design and performance for low and high-volume applications.