Just as shops try to reduce the fixed costs of production, they also look for ways to reduce non-cut time, including tool assembly and setup. Automation can speed these and other tooling tasks, while eliminating the need for doing them manually. From tool cleaning and assembly to presetting and delivery, virtually every aspect of today’s tool management has the potential for being automated.
To accomplish this full tool automation, multiple technologies must work together as a seamless solution, integrating tool storage, robotics, machining cells, programming and tool preparation and presetting. REGO-FIX has targeted the last portion of this challenge, especially because of the advantages our customers can achieve with automated tool preparation and presetting.
At its most ambitious, tool presetting automation can form the basis of advanced unattended lights-out operations, enabling shops to add shifts, productivity and profits without additional staff. Even a more-modest implementation frees shop employees from the time-consuming tasks involved with tool setups while it empowers less-skilled workers to tackle a wider range of workflow tasks without much additional training.
The tool automation process relies on a constant flow of data. Sensors count tools, and tiny Radio Frequency Identification (RFID) tags store information about each one, including type, size, previous use and current condition. The system also correlates tools with the tasks that will use them, based on a list of project attributes entered into the data management system during job setup.
At the start of a fully automated presetting process, a robot inserts a clean tool into an equally clean collet, assembles and presets it and loads that assembly into a toolholder that then loads it into a mobile cart of finished tools. The cart follows GPS signals or machine-readable lines in a shop’s floor to reach a specified work area.
Once the cart arrives at its tool-delivery location, machine-cell robotics move relevant tools into storage carousels where additional automation processes locate and load them. After the machine tool completes the part, automation removes the tools from the cell and loads them back into a cart for a trip to a disassembly station and even a regrinding process if necessary.
All these steps rely on equipment compatibility to load, preset and unload tools from an automatic clamping unit into a machine that conforms to the automation system. To develop our automated tool presetting concept, we began with our powRgrip clamping system toolholders and a PGU-9500 automatic clamping unit modified for compatibility with a Universal Robots articulated robot arm and a Zoller presetter.
To work with the other parts of the automation system, the powRgrip clamping unit needed pneumatic cylinders; alterations to its door design, valve and button-control systems; and specialized wiring to connect it to the central terminal block to which the robotic PLC attached. After we made those changes, the system completed tool setup with no human intervention. The robot signaled the modified PGU-9500 unit to perform its press-in and press-out cycles for the powRgrip tool loading/unloading process, moved holders to the presetter for tool-offset measurement and placed completed tool assemblies into a finished tray.
The highly secure, repeatable, accurate and quick powRgrip mechanical clamping process provides an ideal assembly system with or without automation. By contrast, shops that rely on heat-shrink type toolholding systems quickly find that the process itself adds assembly complications. A heated tool expands, which temporarily changes its dimensions. By the time an automated system writes measurement data to the RFID chip on a tool in a heat-shrink toolholder and the assembly arrives in a robot’s cart, the tool cools and shrinks by several microns. Left uncorrected, that change in dimensions could have potentially devastating effects on part accuracy.
To account for that dimensional shift, a presetting system either must wait for the tool to cool before measuring it or use a complex compensation formula to account for the size difference. The wait adds production time; the compensation formula add complexity and the potential for mistakes. Of course, our powRgrip system introduces no heat and yields cutter/toolholder assemblies that are ready to use immediately.
At REGO-FIX, we’ve shown the importance of toolholding systems in streamlining toolroom automation to remove production delays and simplify accurate tool measurement. Full-scale automation from toolroom to machine tool and back again requires an infrastructure investment that demands large parts volumes to make it cost effective. As big companies develop these big systems, their automation developments will benefit smaller companies. The full “trickle-down” effect may take a few years to reach smaller shops, but the tool-presetting technology will arrive sooner rather than later.