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Across every industry, manufacturers are working to meet growing customer demand in a globally competitive market.

Despite a widening skills gap, by organizing advanced technology into highly optimized work cells, manufacturers are maximizing productivity through automation.

Specialized equipment, like a deep-hole drilling system, often is challenging to integrate, which quickly can create production schedule bottlenecks. To eliminate the risk, shops that perform deep-hole drilling should seek out OEMs that understand the needs of high-production manufacturers and have the capabilities to bring technology into the factories and work cells of the future.

Deep-hole drilling systems, which can produce holes that exceed a 20-1 depth-to-diameter ratio, are a unique class of manufacturing equipment because of the focused tasks they conduct. An increasing number of machining centers boast deep-hole drilling capabilities, but these machines simply cannot operate at needed speeds, particularly for parts that require exceptionally high accuracy. Manufacturers that must perform deep-hole drilling capable of rapid production and high throughput should instead select machines designed for the task.

Automating Holemaking

These shops increasingly opt for deep-hole drilling systems that also work with automation. In a typical deep-hole drilling work cell configuration, such as one for producing rifle receivers or automotive shafts, the equipment can use automation to time its cycle completion to mesh with other production processes. For straightforward automation, conveyors and pick-and-place robots move and position parts for deep-hole drilling with exacting repeatability and accuracy while automatic toolchangers, doors and inspection stations keep parts moving swiftly into, out of and around the cell.

Because deep-hole drilling tends to apply to long, cylindrically shaped parts, workpiece configuration eases or complicates some aspects of automating load-in and load-out cycles tied to drilling operations. Workholding axes, for example, can provide automatic part gripping with pneumatic or hydraulic chucks operated through advanced controls for deep-hole drilling systems. In this configuration, machines can pick up a part, drill it and set it back down on a conveyor or part collection area. In deep-hole drilling systems themselves, specialized designs also offer automatic chucking, while robot-tending systems can add further flexibility with end-of-arm tooling, workholding and measuring systems.

As the automation configuration grows more complicated, however, manufacturers require an OEM that can act as a collaborative partner to find available solutions or engineer individualized products for unique applications or production lines. Shops that depend on deep-hole drilling as part of a high-production environment should seek a partner that has a demonstrated record of working directly with manufacturers to modernize processes and create robust automated work cells.

Gundrilling Application

UNISIG, for instance, worked with a manufacturer of rifle barrel receivers to help it accommodate growing demand and relieve production bottlenecks. The manufacturer’s older gundrilling machines were replaced by a multiple-spindle machine, the UNI25HD. It had the power and controls necessary to apply indexable gundrilling tools, significantly improving feed rates.

To enable fast one-piece-flow manufacturing, UNISIG integrated the system via automation for in-feed, pick-and-place, conveyor loading and automatic clamping, which fed two lathes that turned the parts. The result was an effective work cell that produced more than 100 parts an hour, a dramatic financial and process improvement.

The viability of automated deep-hole drilling production can depend on tool life and part length. At extreme depths, for example, some parts require more than one set of inserts to produce a completed hole, and the high level of hardness of some workpiece materials causes rapid tool wear. To overcome this challenge, UNISIG programs its machines to detect wear and predict when a tool will reach its breaking point, allowing operators to prevent a failure that could stop the line.

For further process efficiency, deep-hole drilling machines should have either a CNC or programmable logic controller. Both can integrate with other control systems and interface with a controller in the work cell. Systems such as a fully automated barrel cell are capable of unmanned, lights-out production with efficient programming.

Deep-hole drilling equipment’s application-specific configurations suit the production of parts that necessitate techniques and processes that go beyond the easy capabilities of general-purpose equipment. In years past, many manufacturers thought of this kind of specialized equipment as old-fashioned and a drag on production. But with the right equipment—and a partner with the right engineering and applications expertise—deep-hole drilling in work cells can keep up with the productive factory environment that manufacturers need to succeed.

Deep Hole Drilling Control – Demo

By Sean Hayes, Controls Engineer, UNISIG
Originally posted in Advanced Manufacturing

Like their peers in the manufacturing sector, many deep hole drilling machine OEMs rely on commercial off-the-shelf (COTS) controls or reuse systems from other machine tool platforms they produce. This approach is efficient but often fails to provide a user interface designed specifically for deep hole drilling machines. So some deep hole drilling machine OEMs have opted for custom controls that not only enable greater levels of accuracy but also allow for the optimization of the deep hole drilling process itself.

The process requires careful operator supervision, but a well-constructed control can easily display all pertinent data necessary to facilitate the real-time management of drilling performance. To truly optimize the process, controls must allow for fast and easy on-the-fly manipulation of the most important factors in deep hole drilling: thrust load and feedrates of the drill; the tool and work spindle torque; and the coolant pressure and flow.

For machines with COTS technology or a repurposed CNC platform, such changes to or manipulation of the program after starting a drill cycle is all but impossible. With controls designed for deep hole drilling, though, overriding the program is possible during operation and encouraged.

Deep hole drilling professionals are thrilled to be able to make on-the-fly changes to the speed and torque of the spindle, as well as the feedrate and thrust load of the drill. With this fine-grained control, operators can adjust the feedrate and spindle speed to address issues like chip management and the straightness of a hole. Coolant flow can then be changed to optimize chip evacuation for that application.

Additionally, today’s deep hole drilling control systems aid users in finding the balance between job speed and tool life. As they encounter various materials, shops can make carefully graduated changes that either reduce wear on the equipment and/or tool or that shorten cycle times. Alongside spindle torque and thrust load, the coolant type, flow and pressure can all significantly affect tool life.

While controls designed for deep hole drilling allow experienced operators to make on-the-fly parameter changes, the controls also reduce the learning curve for inexperienced operators: Modern controls let users generate programs by simply inputting part and tool parameters. If some of the data is unavailable, the controls feature tools that will calculate such factors as recommended spindle speeds for tool rotation and workpiece counter rotation based on the known data.

Likewise, operators can easily configure a new tool and its offset, import programs over an Ethernet connection and handle other functions through the innovative human machine interfaces (HMI) of today’s controls. Unlike previous generations of drilling machines, current HMI-based solutions present users with all of the data necessary to set up a deep hole drilling operation.

That same simplicity and ease of use makes these systems far more modular. Today’s deep hole drilling machines can easily be upgraded to become fully automated with the help of robots that can transfer materials to other stations. These systems can then easily integrate into cellular manufacturing settings.

Advanced deep hole drilling controls can now even assist manufacturers in protecting their investment with a suite of safety features and fail-safes. Software in the controls can alert operators when problems like dirty filters or metal chips clogging the tool threaten to cause significant damage if not corrected. The software can also keep track of how often tools are used, or when a machine is due for scheduled maintenance, so that shops can make any necessary repairs or replacements with the least amount of production downtime.

Fully integrating the control system with the drilling machine requires building them in tandem. An advanced control’s ability to monitor mechanical processes and provide precise feedback, for example, requires a high-efficiency, low-friction system designed around the control’s motion control objectives. Likewise, coolant pumping systems must have the intelligence to vary the process as operators override parameters, yet be low maintenance and robust for long life. Only machines built around such intelligent control systems, and vice versa, can offer operators the highest level of on-the-fly process visibility and management.