Off-the-shelf cases and subracks offer certain advantages. They are easy to order and are delivered fast, yet the market balance has shifted significantly towards individualised products. With the emphasis on modification and flexibility from the development stage, however, off-the-shelf products often cover around 90 per cent of all requirements.
The concept is demonstrated by subracks, which are used in a variety of market segments and applications. Modular subracks are based on a product platform and can be fitted with different off-the-shelf components to create a range of different products on a unified basis.
They can be configured to suit different dimensions, price structure and also static and dynamic loading levels such as shock and vibration resistance, electromagnetic interference shielding and individual internal mounting options.
A standard subrack consists of at least two side panels and four horizontal profiles. Additional accessories include cover plates, front panels, rear hoods, guide rails and various parts for internal fittings and EMC shielding. Subracks of this type can be individually configured and the high level of versatility provides great flexibility in design and construction.
Cases constructed according to the same principle also allow a high degree of flexibility and keep costs down for the user. Another trend for cases is the constantly increasing level of miniaturisation of the electronics. Thus, in addition to the established 19in market, there is now also a growing market for non-modular applications.
A simple ‘box’ to accommodate a motherboard, a large PCB or an ARM module are now the subject of regular inquiries. Small cases of this type also offer solutions for holding non-standard PCBs for various applications in industry, railroad systems, measurement and instrumentation, security applications, medical technology, energy systems and communications and network technology. They are particularly popular in the area of embedded systems for computer-on-module (COM) solutions.
Here again, well-designed development concepts pay off with flexibility in terms of case shape, dimensions and fixing options.
Overall, customers of cases and subracks are making increasing demands for extra services. As fewer and fewer electronics manufacturers can afford their own mechanics division, requests for particular modifications, machining or even complete assembly are growing constantly.
Simplification of the ordering process is also a recurring theme. An extensive range of off-the-shelf component options is necessary to create individualised cases and subracks, but this can make for a stressful experience when ordering.
To help, some manufacturers offer subracks as pre-defined kits, created to satisfy the commonest customer requirements for specific application areas. By specifying the required dimensions and intended application, customers can order the complete product with a single order number. The kit contains all the components and some pre-installed parts such as threaded inserts and EMC gaskets.
In the quest for time and cost savings, more and more customers expect cases and subracks to be supplied fully assembled. This may range from assembling the mechanical, electrical and electronic components, through to fitting additional customer elements supplied to the case or subrack manufacturer by the customer.
The commonest modifications requested for off-the-shelf product include different height, width or depth dimensions, drilled holes for lamps, LEDs and switches, cut-outs for connectors, consoles and special colours. Such modifications also affect the design and processing of the front panels of a 19in subrack or case. A variety of off-the-shelf front panels and plug-in units with various dimensions and finishes further facilitate affordable customisation.
Particularly for building prototypes, pre-production or small production runs, it is often essential to carry out the machining in just a few days, so that any corrections or modifications can be made quickly.
It goes without saying that CAD data should be provided for electronics designers. Simple online access to off-the-shelf products is assured and 2D and 3D product data can be downloaded from here. Customers can mark any desired mechanical processing, such as different cut-outs, directly into the file on his own CAD system.
Customisation, and the need for support and services, will continue to grow in the coming years. Only through constant observation of the market and close contact with customers can such developments be detected in good time and successfully implemented.