Four Mechanical Assembly Details that Make All The Difference

Cable assemblies bring together the output of all the processes that go into making a cable or wire rope system work: wires that compose the cable, cables that hold the fittings, fittings that attach to the object or objects that some force is being applied to. Each individual component is interesting in its own right but brought together the finished cable assembly is impressive in that it is the only way you can utilize a cable or wire rope to apply the forces in play. This is what makes understanding how all element of the assembly work together and affect the performance of the finished assembly.  

You should always speak with a professional to understand the potential design elements that will satisfy your performance demands before you develop a cable assembly solution. This will eliminate potential failures or unexpected complication before you discover them in practice! Here are a few details that can make all the difference in avoiding issues, if not downright failures:

Application

Understanding the requirements of your cable assembly application is important to selecting the proper configuration of components. There is a large difference in the performance requirements between an aircraft flight control and a water-skiing rope. However, if not specified, you could potentially develop a solution that has the proper type of configuration (two eye ends or a threaded stud and a stop), but not practical or safe in your application. You will need to determine how the finished design will be used: Will it be cycled over a pulley or static? Will there be steady weight applied to the assembly, or the potential for a shock load? Vibration? Twist? Chemical exposure or abrasion? All of these play a role on the engineering of the required solution.  

mechanical-cable-assembliesEnd Fittings

The actual ends that you apply to the cable assembly will determine a lot of the performance characteristics and dictate most of how your design responds in practice. While the term “eye” refers to any fitting that has/creates an opening to attach to some other object, there are a wide variety of options that could be selected. For example, stamped eyes provide a nice solid attachment to cable and allows for the assembly to be screwed into a part very easily. They are, however, prone to bending and can create a failure point in the neck of the fitting if the system isn't designed properly. Likewise, and eye can be created by looping cable back on itself and securing with a sleeve. This provides a strong attachment point for the assembly, but can also result in abrasion and premature cable failure at the bearing point of the eye due to exposed cables.  Be sure to understand the different options for each style of fitting before you place them into your requirements.

Tolerance

The tolerance of any measurement in a cable assembly affects not only its performance, but the cost of manufacturing and the potential solutions to any given wire rope problem. For instance, if your application has a tolerance of 1” over 2 feet, there is a much broader range of potential solutions available to the cutting, swaging, and assembly practices that can be used. It also opens up many more styles of end fitting for use than if the tolerance were, say, .010: over the same two feet. Consideration of the assembly tolerance should focus not only on the cable itself, but on what adjustments can be made in the part it is being attached to. Keep in mid that machined parts can hold a lot tighter tolerance than can formed parts (like swaged fittings, or the swaged portions of fittings). Machined options for tight spaces tend to provide a better solution for const control then trying to specify a very tight tolerance on a formed part. Bottom line: understanding the critical measurements and tolerance will allow for a better solution, both in performance and in costs            

 

Testing requirements

Understanding the performance needs if your cable assembly, and the options available to test those outputs can greatly impact the potential solution that can be developed. Similar to the tolerance situation, set up and certification testing can add a significant time and resource requirement to any cable assembly production. If this is required, given the application for the product, then picking components and processes that will meet those requirements are crucial. If there is flexibility in determining the performance or proving the process, then, again, this opens more options for a final configuration.

As with all manufacturing and configuration decisions, you should always discuss your options with cable assembly professionals before finalizing your solution. Sanlo has the knowledgeable staff and years of engineering experience to help. If you’re in the market for a cable assembly, be it a new product or to resolve issues that you’re having with an existing product, don’t hesitate to contact us.  We can provide the expertise required to solve your problem, no matter how complex.