#Product Trends
Have it Your Way: How to Make Customised Linear Motion Affordable
Given that more than 25 percent of linear motion system projects end up requiring at least some degree of customisation, it could be beneficial to prepare for that eventuality from the outset.
Customisation may not always be top of mind when machine designers are selecting motion control vendors. The hope is usually that they will find exactly what they need in the catalog and avoid what they believe to be the higher costs, delays and risks associated with custom solutions. But, given that more than 25 percent of motion system projects end up requiring at least some degree of customisation, it could be beneficial to prepare for that eventuality from the outset.
Including customisation expertise on the list of vendor selection criteria could help avoid higher costs and delays if the application should require some modification down the road. Learning about the varying customisation capabilities of different vendors, may result in the finding that customisation can be much faster, less expensive and not as risky as originally thought.
The most important question to ask before closing on any motion control purchase is “What happens if we can’t get my needs met with standard products?” A few key factors to consider include:
1. Commitment. For some vendors, customisation is part of their business model, while for others, it is something to be avoided at all costs. If the vendor website has dedicated customisation pages with detailed lists of characteristics that can be customised, you are probably in good hands. If, on the other hand, there is little or no mention of customisation, you should find out why. It could be because of deficiencies in any of the other areas mentioned below on this list.
2. Experience. How often have they had to modify a product? Can they give examples? How did the need for customisation impact cost and delivery?
3. Capability and scale. Do they have any special equipment for customisation? What does it do? What is the minimum number of potential products for which they would consider customisation? Are they set up to handle smaller batch runs or will they customise only for large product runs?
4. Supply chain flexibility. Are they vertically integrated so that they build most of their subcomponents from raw material, or will they be waiting for your parts to arrive on the next container boat?
5. Process. Can they give budgetary quotes right away? How long does it typically take to get a quote for a nonstandard product? Will there be a dedicated engineer? Can the prototype be built online? Can the vendor produce the product directly from a CAD model?
6. Engineering problem-solving. After all else is considered, perhaps the most important factor is the creativity of the vendor’s engineering team in terms of helping to reach an optimal solution. Will they take the time to understand the needs?
While it is common for machine builders to think of customisation as an all-or-none situation, many needs can be met with a relatively simple modification of standard products, which, depending on the vendor’s experience, can often be delivered in days rather than weeks or months. Sometimes all that is needed are some special machined shafts, connectors or mounting ends. Here are some examples of linear motion customisations that have helped designers adapt to irregular spaces, improve ergonomics or reduce costs.
Adapting to irregular spaces
Usually, the need for customisation often emerges after the project begins. For example, a company that itself specialises in customising semi-trailers required several modifications to adapt actuators for use in ramps, stairs and movable floor assemblies. Fitting ramp lift actuators inside the trailer wall required rotating the motor 90 degrees. The ability to mount actuators within custom ramp frames while still connecting to the standard mounting points required extending the actuator tube by four inches. Simplifying future maintenance involved retrofitting the wiring connections with an easily detacheable harness.
Lowering the price point
Even if the business relationship begins with a customisation need, it can sometimes be met inexpensively by mixing and matching standard components. For example, a supplier of CNC tubing and pipe bending systems sought help in designing a new machine to meet market demand for a scaled-down system. Their high-end system used two linear slides bolted together in a cross configuration to control motion on an XZ axis, using stepper motors to drive a 600 mm ball screw on each axis. The long length of the screw required support bearings on both ends and a special coupling to the stepper.
The first thing the linear motion component manufacturer did to reduce the cost was shorten the shaft to a 280 mm lead screw with a 150 mm drive, which eliminated the need for support at both ends. Specifying a stepper motor with an integrated motorised lead screw (MLS), reduced the need for external support further because the MLS motor bearings could support the load themselves. And because the lead screw and MLS rotor are combined into one part, there was no longer a need for external coupling of the screw and the rotor.
An open palette
These are but a few examples of customisations. The range of options is wide: Customising stroke and extracted length down to millimeter scale; enhancing control by adding encoders; complying with industry regulations by adding certification; selecting a more aesthetically pleasing finish; implementing a custom adapter housing; or improving voltages or clutch handling. Even those are just mere examples of what could be customised on an electric actuator. This same degree of customisation applies to shafting, screws, Ball Bushings®, linear guides and a host of other linear motion components.
In these days, in which machine designers are having to do more, faster and with fewer people, the more uncertainty they can drive out of the process, the greater their chance of sustained success. Acknowledging the fact that the need to customise some aspect of the project is a likely possibility and taking a few minutes to be comfortable that you have partnered with a vendor that has deep customisation capability can save money and headaches down the road.
