TRESKE PRECISION MACHINING
Collaborative robots help inspection keep pace with machining in a custom, digitalized workflow for complex aerospace and defense parts.
Treske Precision Machining
QC / Thread Checking
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Tim Gilboy, production manager, demonstrates hw controlling the thread gaging process with the robot pendant eases changeover from gage to gage. The arm’s seventh axis also adds flexibility. Photo Credit: Treske Precision Machining
How Automation Keeps Quality in Control
Featuring a seventh axis of motion that enables reaching around doors and other objects, Treske Precision Machining’s first-ever collaborative robot is ideal for machine-tending applications. However, machine tending is Plan B. Plan A is to automate manual, hand-gauge inspections of threaded holes.
This machine-tending backup plan does not indicate any lack of confidence in the arm itself. After all, the seventh axis – and even more so, the system’s simple programming – helped spark the idea to automate thread-checks in the first place. As has been the case with past automation projects at Treske, the task is complicated due to the nature of the work, which on any given day might consist of as many as 1,200 unique part numbers winding their way through the shop.
The experience with a second collaborative robot has been very different. As just one component of a pre-integrated machine-tending system that comes standard with all the necessary mounting, part storage and programming, this six-axis arm is already busily loading and unloading coordinate measuring machines (CMMs).
Is “job shop” automation getting easier? Perhaps. Regardless, nothing about Treske’s experience indicates that automation will ever be easy, at least not for those who hope to maximize its potential. Even the essentially plug-and-play CMM-tender works so well in part because it plugs into digitalized workflows that the company has already developed. In this context, the quality control department’s first robots are among the final pieces of an automation puzzle that has been in the works for years.
Whatever the extent of the challenge, intense competition and increased data collection requirements leave no room for Plan B. If Treske’s growth is to continue, the pace of inspection must match the pace of machining. Keeping pace requires providing tools that can liberate quality control personnel in the same way that pallet systems and other physical automation already liberate production personnel. Otherwise, inspectors become essentially glorified machine tenders. “We want to use our inspectors as inspectors,” explains Scott Ferguson, business development manager. “They are most beneficial in reviewing reports, solving problems and providing feedback to manufacturing.”
Treske’s goal is to automate one of the most time-consuming tasks in quality control by integrating a collaborative robot with a dedicated thread-gaging head. Photo Credit: Tim Gilboy, Treske Precision Machining
The Final Puzzle Piece
Robotic thread inspection is not new, but robotic thread inspection in a job shop environment is ambitious. As opposed to loading and unloading a machine, the task requires manipulating diameter pins, pitch gages, “go/no-go” gages and other thread-checking instruments around the part, re-orienting as-needed to align with each hole.
By the time of the shop visit that led to this article, the team had poured months of work into this application. Yet, they seemed undaunted by the challenges to come, preferring instead to riff on the possibilities of leveraging the unusual seventh axis of the arm, an OB7 from Productive Robotics, to access both parts and gages stored in the adjacent docking unit. Further conversation reveals that Treske has always thrived on this kind of creative problem solving, and that in-house automation projects like this one have driven this company’s growth since its deliberate shift away from semi-conductor work in the late aughts.
Since then, the shop floor has come to be dominated by five lines of Makino HMCs, all serviced by rail-guided pallet shuttles jetting back and forth between loading stations that break up the surrounding safety fencing. Whether during the day or skeleton-shift nights, personnel rely on workstation computer displays for instructions and information, such as breakdowns of the tooling in each machine and the workpieces on each pallet. Although some of this data was already available through the Makino cell controllers, this output is customized to be easier to interpret and to prevent the need to “dig” for insights, says Mike Olander, operations director.
In-process inspections are almost continuous. Whether collected with shop-floor gages or on a CMM, readings feed directly into a real-time statistical process control (SPC) analysis system. The people measuring the parts are empowered by clear prompts and instructions and easy data entry, Olander says. The people watching the trend lines are empowered by standard, custom formatting that reduces the risk of drowning in what Ferguson calls “data overload.”
Frequent in-process inspections, facilitated and streamlined by the intranet, serve a dual purpose. First, they prevent shop-floor bottlenecks by promoting quality parts off the machines. Second, they prevent inspection bottlenecks by collecting data mid-process rather than at the final stage. The “problem” is that throughput has accelerated so fast in recent years that the company has essentially become a victim of its own machining automation. “We could handle managing more work, and we could handle machining more work, but the automation in quality needed to match production,” Ferguson says.
Hence the introduction of the OB7 for thread verification. Meanwhile, the second robot is already helping quality control keep up with machining. As part of the “Tempo” system from Hexagon Metrology – the supplier of Treske’s 6 CMMs – it has freed personnel from not only machine-tending, but also from yet another extensive in-house automation project.
By default, Tempo’s interface is organized around the job number. As shown in this image of the scheduling screen, Treske’s system also includes fields for inspection type and serial number (both of which are drop-down menus). Overall, custom data formatting has been critical for pulling the most relevant information into custom, easy-to-interpret displays that drive inspection workflows and decision-making. Photo Credit: Treske Precision Machining
Keeping the Pace
Based on testimony from Ferguson and Olander, Tempo is aptly named. For one, it increases the tempo of inspections. This became necessary with the addition of higher-volume jobs (that is, on the order of several thousand parts per year rather than the more typical several hundred), along with increasing demand for final inspections on entire batches of parts, regardless of the level of in-process inspection. With both forms of measurement competing for time on the same CMMs, inspectors could not keep up, and the feedback loop slowed. Siphoning final-inspection work as-needed to a dedicated, Tempo-tended CMM helps keep other CMMs open.
For another, the system helps inspectors manage the tempo of their work. For example, repeat batches of a high-volume part might take only 2 minutes each to inspect – too little time to attend to anything other than the CMM. Tempo not only eliminates the need to stand in front of the machine, but also works at a precisely predictable pace. Inspectors typically carve out 10 or 15 minutes to reload the drawers and keep the system going when its work is almost finished. Rather than stressing about work piling up in front of the CMMs, they can maintain focus on more thought-intensive tasks, such as reviewing data and troubleshooting. “They can really do everything they’ve always done, but with an extra machine’s worth of runtime throughout the shift,” Ferguson says.