5-Axis Machining: Combatting Cumulative Error
Errol Burrell 10.15.2021
It’s a common understanding that small errors can accumulate over time to create big consequences – but this is especially true within the manufacturing realm. Industry data experts have dedicated their professional careers to expansive spreadsheets and formulas to track and combat cumulative errors within the machining tool itself.
As unplanned human error enters the equation, the impact can become even more exponential – creating scrapped parts and delaying your overall production schedule - both of which can become detrimental to your bottom line. But this does not have to be the case. Many shop floors are adopting 5-axis machine tools as a new norm to combat the cumulative error effect. Let’s take a closer look at how 5-axis machining, and especially Okuma’s 5-axis machine tools, can help achieve such conclusive results.
Compounding errors during the production process
Machinists may find themselves manually handling a part and shifting it from machine tool to machine tool in order to complete the setup and production process. It comes without surprise that the more frequently you move a part between machine tools, the more opportunities for errors to occur.
Individual errors could be introduced by inaccurate positioning of a fixture, programming errors, vibrations and chatter, the tool wear on each machine, or even the thermal differences encountered between machines. Unfortunately, the list of errors that can affect machine accuracy is too numerous to include within this blog post, but each small miscalculation or misstep that takes place while moving the part through the production process, no matter how insignificant, can compound and spell disaster for the final product.
So why continue to transfer parts between machines when it’s no longer necessary with more advanced technologies such as 5-axis machine tools?
Utilization of a single workstation and machine tool
A 5-axis machine is a powerful, flexible solution for solving cumulative errors obtained by moving a part between machine tools. Since the 5-axis machining process involves shifting the cutting tool and workpiece utilizing the X-, Y-, and Z-linear axes and rotating two of the three A-, B-, or C-axes simultaneously during a machining operation, this category of machine tool can easily perform milling, turning, and most other operations that are needed to complete a part – all on a single machine.
More concisely, all sides of a part can be processed within a single setup, program, and operation, and therefore the part does not need to be touched or transferred to other workstations once the production run is started. This eliminates the human element, achieves fewer chances for errors, and almost guarantees a higher accuracy part. Elimination of tedious setups and movements between machines also grants quicker cycle times which in turn increases the profitability of a single job or contract.
Deploying a 5-axis machine tool is just the beginning of removing the harmful effects of cumulative error, it’s equally important to select a 5-axis machine tool that is designed to embody characteristics to reduce errors as well.
Taking the reduction of errors to the next level
The goal of any great machine tool is to provide relentless accuracy and repeatability. Okuma machine tools deliver on that goal time and time again. As the industry’s only single-source provider of machine, control, spindles, drives, and more, every part of an Okuma machine tool is designed to work in harmony with each other, thus maximizing the mechatronics of the machine.
The pure mass and weight of a 5-axis machine tool matters when attempting to fight unwanted errors and inaccuracies. While cutting, a spindle in motion creates force that generates throughout the machine tool. The way a machine tool’s structure reacts to the displacement of this energy plays a critical role in satisfying basic machining requirements such as precision, accuracy, and performance. Okuma machine tools, including our 5-axis product offerings, are constructed of the most solid materials and rigid design to absorb this energy and nearly eliminate vibration at the tooling level that can cause errors and defective part manufacturing.
Machine performance is dependent on a stable environment, one that is not only void of errors but also ensuring machine characteristics are consistent. As mentioned before, part movement between machines may introduce changes upon each machine’s respective startup which can include thermal deviations. Using a 5-axis machine tool eliminates the multiple machining workstations, however, Okuma’s unique build structure takes the responsibility of a stable environment one step further. Our Thermo-Friendly Concept combines control technology and machine design to minimize the amount of heat generated during the cutting process and manages heat that can’t be eliminated in order to reduce errors, improve quality, and diminish waste.
Incorporating intelligent technologies, such as Okuma’s 5-Axis Auto Tuning, during the 5-axis machining process also removes geometric errors by compensating for the errors through precise position measurements.
Heightened expectations around part accuracy
The requirements for part accuracy continue to tighten with continuous technological developments and heightened expectations within industry segments that require more complex parts to be generated. Quite simply, machine shops that cannot produce a consistently accurate part risk the potential of losing business to those that can. This means that choosing the correct category of a machine, such as a 5-axis machine tool, and the most advantageous manufacturer of that machine tool is imperative in reducing or even eliminating cumulative error and keeping your customers returning.
Do you feel 5-axis machining can help your shop with an existing cumulative error issue? Explore our in-depth 5-Axis Machining Guide or reach out to your local Okuma distributor to help guide you through the evaluation of incorporating a 5-axis machine into your shop’s plan of action.