When it comes time to choose a linear rail for medium-precision applications, many designers automatically opt for a profiled rail.
In doing this, however, they automatically preclude certain types of linear rails which can prove to be much better suited – not to mention less expensive – than the tried-and-tested rails that are usually chosen and used. This tendency to stick with familiar options can have far-reaching consequences in production planning and control.
Areas of application
Medium-precision applications generally require rails with a precision in positioning of between 200 microns and 2 millimeters. When we’re talking about the mechanical design of machine elements, this level of precision is often more than sufficient for many industrial needs.
This type of specification is very common in logistics or in automated production systems and installations, such as pick-and-place machines, portal robots and packaging machines.
Even with the design machine components and tools, which you might think would always require the highest precision, have components that don’t need such exacting standards.
Part loaders, tool change devices, and doors don’t demand the same levels of precision as the rails supporting the axes used for piece handling. It’s all about understanding the specific needs of each element in your machine design.
Considering this, using rails designed for medium-precision applications instead of specialist profiled rails can prove to be a winning choice.
What factors to consider in the design phase
Machine component design involves far more considerations than you might initially think. You need only consider a series of aspects which come into play when designing the new application to understand how many factors need to be accounted for and what they are.
Let’s dive into some examples, shall we? In the realm of machine component design, here are just a few of the things you’ll need to keep in mind:
- What is the cost of any operations to adjust or rework the structure in order to manage imprecisions in construction and misalignments, both of which are factors to be avoided entirely when using high-precision rails?
- How much time am I prepared to spend on assembly?
- How much will wear and tear on the rail ultimately cost?
- What and how many functional failures am I prepared to accept by opting to use extremely precise, rigid rails?
Avoid “hidden costs”
If not managed properly by selecting the right rail, all these factors increase the time to market and the emergence of what are usually referred to as “hidden costs”, which have a significant impact on the “total cost of ownership” of a linear motion application.
When calculating machine design cost, it’s crucial to look beyond the immediate expenses of materials and labor. The choice of components, such as rails, can have far-reaching financial implications throughout the project lifecycle.
Selecting a rail that exceeds the necessary specifications may result in unnecessary expenditure. While such a rail might function adequately, it often leads to inflated machine design costs.
The impact extends beyond the initial purchase price, potentially requiring more extensive maintenance or specialized installation tools, thereby increasing the total cost of ownership for the linear motion application.
Take an in-depth look at these topics and eliminate hidden costs by choosing the linear rail that is best suited to your application.
