Moldmaking Technology Magazine highlighted Concours Mold Inc.'s investment into UNISIG's USC-M50, and two USC-M38 machines. Concours highlights the reduction of several other machines on their floor


USC-M Machine Benefits Featured in Case Study

Moldmaking Technology Magazine highlighted Concours Mold Inc.’s investment into UNISIG’s USC-M50, and two USC-M38 machines. Concours highlights the reduction of several other machines on their floor, drastically reduced setup time, and less dependence on outsourced work, among other benefits. The case study goes in depth into the impressive effects on their manufacturing process, throughput, and overall business impact.

“As our company announcement said when we launched our third Unisig USC-M in February 2018, the USC-M series brings unmatched capabilities in a single, game-changing machine,” Ergun says. “This is our tomorrow.”

Photo Credit: Concours Mold, Inc.
The future of the auto industry is interesting but uncertain. No one knows how quickly electric vehicles are going to replace gasoline- and diesel-powered vehicles, how completely it will happen


Deep Hole Drilling Aids Change in Auto Manufacturing

The future of the auto industry is interesting but uncertain. No one knows how quickly electric vehicles are going to replace gasoline- and diesel-powered vehicles, how completely it will happen, and when it will occur in passenger cars as opposed to SUVs and heavy trucks. However, we do know that fuel economy standards continue to progress and drive vehicle design toward smaller displacement, higher-technology engines.

Off-center automated drilling machineAs a result, technology that was developed years ago for high-performance vehicles is now becoming mainstream. For example, sodium filled valves, which formerly were used in only extremely high-performance engines to manage heat in the valve train, are becoming more common. The same goes with hollow camshafts, which reduce energy-consuming rotational inertia and provide opportunities for engine management.

Within vehicle drivetrains, today’s automatic transmissions now have as many as eight or even 10 speeds instead of five or six. This wide selection of gear ratios enables smaller displacement engines to provide better fuel economy and deliver higher performance.

These kinds of technological upgrades for higher performance and economy are not new, but previously were considered too costly for general use. Now, advanced manufacturing and materials technology make common application of these upgrades viable.

Enabling Cost-Effective Production

Deep hole drilling is one advanced manufacturing technology that allows for the cost-effective production of key features of those performance-boosting parts. Sodium-filled valves, for example, have holes drilled the length of the valve stem in which liquid sodium circulates and draws heat from the valve head. Precise deep hole drilling methods enable hollow and more energy-efficient camshafts to be manufactured. Complex multi-speed transmissions feature shafts with multiple off-center holes of varying depths for lubrication or hydraulic sequencing. The holes in the shafts are too deep to produce effectively on machining centers, so deep hole drilling machines are critical in those instances.

Balancing Volume Output with Flexibility

Other manufacturing challenges in automotive production can also benefit from today’s advanced machine tool technology. For decades, the automotive industry focused nearly exclusively on volume production. The emphasis was on making as many parts at the lowest cost possible. Flexibility was merely a minor consideration.

Market changes have made balancing volume output with flexibility a major issue. If volume drops on a vehicle program, there remains a need to produce the vehicle cost-effectively. Expanded product mixes created to meet customer desires for different powertrains and other options demand high efficiency regardless of volume.

Consequently, flexibility and spindle utilization have become the main drivers of deep hole drilling machine design. Instead of having a gang of four spindles pounding out parts, a two-spindle machine with a rotary table and X-Y positioning system can provide extremely high spindle utilization along with flexibility. Technology such as automated setup through servo motion to reduce changeover time is also considered in the early concept development of the machines. These systems allow manufacturers to plan and implement small, agile cells to replace large, old-school, high-volume systems.

Benefits of Machine and Fixture Design

A recent customer experienced significant benefits with UNISIG’s machine and fixture design. Previously, the customer was processing a challenging family of parts on a system that involved nearly 20 fixtures. Each part required multiple holes with varying depths and diameters. A bulky, dedicated machine created an unnecessary expense and bottleneck in their production.
UNISIG provided a machine that allowed the company to manage deep hole drilling of these parts with just two pallet-changeout type fixtures, and requiring only the selection of a new part program. By eliminating fixturing, setup, and programming time, the company experiences significant savings every time the machine runs.

Lighter Yet Stronger

In addition to production benefits, a future opportunity for automotive manufacturers that involves deep hole drilling technology is in making vehicle parts lighter yet still maintaining or even increasing their stiffness and strength. Deep hole drilling can produce thin-wall parts such as axles and power transmission shafts, for example, that provide significantly higher mechanical integrity and better improved energy economy.

For instance, drilling a 20-mm axial hole through a heavy 30-mm diameter shaft makes the shaft much lighter while maintaining its stiffness. This lighter shaft has less rotational inertia which, in turn, reduces energy consumption. Designers continually search for such small gains in efficiency and will seek ways to enhance lightness and stiffness throughout the automobile.

As machine tool manufacturers, our job is to listen to our customers, understand what they need, and develop those needs into a solution that is viable from a cost and reliability standpoint. With ongoing advancements in engineering technology, machine manufacturing, and service, what might have been very expensive to do only three or four years ago is now viable. Concepts that once seemed a bit far-fetched are now quite common.

Because of that, we design our machines to provide both flexibility and utilization that will enable our customers to successfully face the expected—but not yet fully known—major changes in the automotive manufacturing industry.

Picture yourself facing knee surgery, under the care of a skilled orthopedic surgeon. Precision instruments, state-of-the-art monitoring equipment, and decades of experience


How to Drill Straighter: Concentricity in Deep Hole Drilling

Picture yourself facing knee surgery, under the care of a skilled orthopedic surgeon. Precision instruments, state-of-the-art monitoring equipment, and decades of experience are on hand, as they conduct a procedure that will ideally lead to more days on the court. The surgical team works patiently and carefully towards a successful outcome, relying on tools to guide their movements with exact precision, placing instruments exactly where they need to be in the body, and not even a half millimeter off. For deep holes in components to be accurate – including surgical tooling – they need to uphold tight concentricity tolerances, and in gundrilling, this happens best with counter-rotation. For a manufacturer, this is vitally important. For an end user, or in this case a patient facing surgery, it can make all the difference.

These precision parts are one of several applications that have deep holes, where concentricity is critical to the function of the part. Concentricity tolerances are achieved when the hole follows the desired axis of the part, eliminating drift from the point of entrance to the exit. In a round part with on-center drilling, this is easily illustrated; some applications may include deep holes which are off-center, or in non-round parts, but still have tight concentricity requirements.

Low concentricity in some applications can result in parts with weak sidewalls, mismatched holes, or even scrapped parts. In other cases, manufacturers may decline production of these components, because of perceived impossibility or unproductiveness. With the addition of a counter-rotating process on deep hole drilling equipment, critical concentricity tolerances can become both achievable and economical.

How Counter-Rotation Improves Concentricity

Drilling a deep hole is commonly achieved by rotating the cutting surface of a tool against the metal of a workpiece with two opposing spindles in a horizontal setup. Typically, this consists of a stationary workpiece and rotating tool, but can also be configured with a rotating workpiece and stationary tool, or a third option, with a counter-rotating tool and workpiece.

Common machining centers use a rotating cutting tool, such as a mill, and a fixtured, stationary workpiece. A lathe, alternatively, rotates a workpiece and cuts with a stationary tool. Much of the time, setups such as these are enough to achieve the goals and tolerances of a majority metal cutting tasks, but are limited when it comes to more extreme tolerances and depth-to-diameter ratios.

A tool-rotate configuration is the least accurate when it comes to concentricity. In this setup, gravity is believed to act on the base and shank of the tool, not the drilling tip, and along with the rotation of the tool. Because of the relative position of the tool and gravity to the workpiece, this configuration produces the poorest results. This tool-rotate process is common for shallower holes on a machining center, but as holes become deeper, and tolerances become tighter, this no longer works as a solution.

Workpiece-rotate-only setups produce holes that are approximately twice as concentric as tool-rotate. A rotating workpiece changes the relative force of gravity compared to the workpiece position, negating some of the effects on the finished hole. A rotating workpiece can be done on a lathe with limited capability, but is ideally performed on a dedicated deep hole drilling machine.

deep hole drilling diagramCounter rotating tool and workpiece improve significantly upon both of these, as the forces are never static – changing relative gravity and orientation will provide drilling conditions without a single constant net direction that the tool will follow. In this setup, the tool is restricted from drifting, and will produce a much more concentric finished hole.

Counter-rotation is easily achievable with the right equipment and setup, whether it is for smaller gundrilled holes, or larger, longer BTA drilled components.

Deep holes are typically classified as anything with a depth-to-diameter (D:d) ratio of approximately 10:1 or greater, and can even reach extreme ratios of 100:1. As deep holes approach ratios of 20:1 or greater, drilling with specialty tooling on dedicated equipment is optimal. Modern deep hole drilling machines are designed to maximize the potential of tools such as gundrill and BTA processes.

deep hole diagram

The Data

To represent the impact of counter rotation, a test was performed on a 4140HT workpiece, 30 inches in length, ¾” outer diameter and a ¼” drilled hole. The depth to diameter (D:d) of this test is 120:1. This part is easily representative of a power transmission shaft or aerospace linkage.

Drilling these test workpieces produced the following results (measured using ultrasound):

  • Rotating Tool, Stationary Work: 0.026 inch drift at 30 inches of drill length
  • Stationary Tool, Rotating Work: 0.015 inch drift at 30 inches of drill length
  • Rotating Tool, Counter Rotate Work: 0.009 inch drift at 30 inches of drill length
    *results may vary based on material, depth-diameter ratio, tooling, etc.

Drilling holes with a 40:1 or less depth-diameter ratio can be done with limited drift using standard drilling practices. Beyond 40:1, counter-rotation really begins to deliver benefits with minimal drift.

Total Drift Comparison, Drilling Methods

  • Rotating Tool - Stationary Workpiece
  • Stationary Tool - Rotating Workpiece
  • Counter-Rotating Tool and Workpiece

Getting Started with Counter-Rotating Deep Hole Drilling

Typical machining centers are often not capable of deep holes greater than a 20:1 D:d ratio, and are not configured for counter-rotation. Rather, dedicated deep hole drilling machines are a superior consideration because they are designed specifically to manage accurate counter-rotation in gundrilling and BTA processes.

Deep hole drilling machines that enable successful counter-rotation include the right components, machined and assembled to maintain superior alignment. These range from the machine base, to rotating bearing groups and spindles, to tool and workpiece support – all of which uphold alignment and work as a system. This allows the machine to maintain accuracy while moving, and hold concentricity tolerances throughout the depth of the hole.

rotating deep hole drilling workpieceFor deep hole machine builders, alignment considerations begin with the machine base. Each component is designed with alignment as a priority,as well as machining and environmental factors like temperature and gravity. Counter rotation may be possible on machines retrofitted with a second rotating group, but will often need to undergo an alignment improvement process which creates additional challenges. Equipment designed with this purpose will have the right combination of benefits to make concentricity tolerances manageable for nearly any operator.

On a counter-rotating drilling machine, a good operator interface will provide a full picture of process information, as well as allow control over process parameters, for fine-tuning and process repetition. Manufacturers can optimize their counter rotation application, and proceed into highly accurate and efficient production.

A general starting point for counter rotation is to allow one third of the total speed to come from the workpiece, and two thirds of the speed to come from the tool. This is a typically recommended starting point for counter-rotating drilling with confidence. Operators can adjust for their specific application, and work with industry partners for recommended parameters to meet deep hole drilling goals.

Productivity Considerations

The addition of counter-rotation in a deep hole drilling process gives operators an additional factor to optimize for both specification and production requirements. The ability to hold improved concentricity tolerances with counter-rotation allows feeds to be run at optimal rates, as well as extends tool life. Manufacturers can reliably produce more parts per hour, with fewer tool changes and improved tool consumption.

For applications where concentricity is indeed critical, the productivity benefits are significant, and easily justify the added capability. Counter-rotation consistently produces a more concentric drilled hole, typically with higher surface cutting speeds, offering clear benefits to manufacturers in both accuracy and efficiency.

Manufacturers can increase capability, improve hole tolerances, and optimize productivity, ultimately cutting costs and providing a competitive manufacturing advantage. With the right resources, drilling deep holes with extreme concentricity is economical, repeatable, and commercially viable.

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.


Deep Hole Drilling Control

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.

UNISIG's CEO Anthony Fettig was featured on , discussing high-feed gundrilling, and the relationship between deep hole drilling systems and the tooling technology that is available.


The Hole Productivity Package – Advanced Manufacturing Feature

UNISIG’s CEO Anthony Fettig was featured on, discussing high-feed gundrilling, and the relationship between deep hole drilling systems and the tooling technology that is available. Indexable-insert gundrill tools can triple feed rates, and are ideal for high-production environments in appropriate hole diameter ranges, allowing manufacturers to modernize their production flow and update capabilities.

Until recently, several types of tooling for deep-hole-drilling operations were considered specialty tools—ones that few cutting tool OEMs offered and even fewer actually supported. Today, many of those tools, such as indexable–insert tools for gundrills, are now readily available as standards and come with effective application support. All of which allows shops to easily implement such tooling and reap the deep-hole-drilling benefits of doing so.

Indexable-insert tooling triples drilling feed rates over those of conventional tools to maximize output. However, to actually run these tools to their full potential, deep-hole-drilling systems must now also generate three times as much power, torque and thrust as well as have the rigidity and stiffness to prevent any vibration.Fortunately though, the higher feed rates of indexable-insert tooling translates into increased output per spindle on deep-hole-drilling machines. That is, a machine using these innovative tools can drill the same number of parts—maintain a certain level of output—but with half the amount of spindles. Consider a production output level that would require 12 to 16 deep-hole-drilling spindles equipped with conventional tools. Indexable-insert tooling allows a shop to achieve that same level of output with only four spindles.

Such productive dedicated deep hole drilling systems mean that process planners/engineers can rethink their production cell layouts for improved cost-effectiveness without sacrificing output. Four-spindle gundrill machines, for example, take up approximately the same footprint as a large lathe. So, instead of four lathes, a shop can put in one gundrill machine and save 75% of the space while still getting the same level of output.

Highly productive gundrills need automation for maximized efficiency—not only external automation but internal automation as well. On its own, a single external robot is unable to load enough parts to keep all four spindles running. Instead, the external robot, or an operator, feeds parts to an internal loader inside the gundrill that then moves parts throughout the machine. This internal integral loader is an indexing “smart” conveyor that distributes the parts where needed.

Deep-hole-drilling process control and tool life management is even more critical for the high-performance machines that run indexable-insert drills, not only to keep operations running smoothly, but also to stop the process in the event of a problem before tool damage occurs. So those deep-hole-drilling system OEMs, such as UNISIG, that have always incorporated, in one form or another, process control and tool life management systems into their deep-hole-drilling technologies are now leaps and bounds ahead of those that have failed to do so.

Advancements in automation combined with the process control capabilities of deep-hole-drilling systems streamline their incorporation into production cells alongside conventional machining centers and other systems.

While it’s possible to perform certain deep-hole-drilling operations on machining centers and even be relatively productive, the deeper the required hole, the more the operation mechanically taxes the machine tool and diminishes its output. All of which leads to increased maintenance and higher tool expenditures.

This strategy also forces shops to add more machining centers to keep pace in the event of any surges in production demand. Conversely, the alternative is to instead integrate a deep-hole-rilling system that would relieve the machining centers of that operation. The cell’s robot could move parts from the machining centers to the deep-hole-drilling system.

Today’s deep-hole -rilling machine OEMs must always stay ahead of the curve in terms of tooling, then modify and engineer their machines accordingly to capitalize on any new technology. Doing so ensures that deep-hole-drilling systems continue to grow in capability and in application versatility to give shops further incentive to rethink the deep-hole-drilling process and how it could benefit their production operations.

Anthony Fettig, UNISIG CEO discusses deep hole drilling tooling