19

Sep

Counter Rotation Maximizes Deep Hole Concentricity

In a routine drilling operation on a milling machine or drill press, a drill’s cutting edges rotate against a stationary workpiece. The opposite is true in holemaking on a turning machine where a stationary drill advances into a rotating workpiece. Either of these drilling methods produce sufficient reliability and hole quality for a wide range of applications. However, other tactics are necessary to produce more exacting tolerances and larger depth-to-diameter ratios.

Drill and workpiece rotation has a major influence on a hole’s concentricity – a key measure of drilling accuracy. When the drill alone rotates in a horizontal setup common for deep hole drilling, accuracy will vary as gravity acts on the drilling tool. A rotating drill can produce sufficient concentricity in relatively shallow holes, but performance will suffer as holes become deeper and less forgiving tolerance wise.

On the other hand, because the direction of gravitational forces relative to the workpiece constantly changes when the drill is stationary and the workpiece rotates, that arrangement can produce holes approximately twice as concentric as the rotating drill approach. While shops can perform rotating-workpiece deep hole drilling on a turning machine, a dedicated deep hole drilling machine using what’s known as counter-rotation will net much better results.

Benefits of counter-rotation

A drilling setup that involves both the drill and workpiece rotating in opposite directions will balance out drilling forces, which are never static in a constant net direction. The balanced forces keep the drill from drifting for a much more concentric hole. With the right equipment and setup, counter-rotation is possible for smaller gundrilled holes as well as larger holes drilled with BTA tooling.

In counter-rotation testing, UNISIG drilled a ¼”-dia. hole in a 30″-long, ¾”-dia. OD, 4140HT steel workpiece. This 120:1 depth-to-diameter application is one typically found in the production of power transmission shafts or aerospace linkages.

Drill drift at the 30″ hole depth was measured via ultrasound. With a rotating drill and stationary workpiece, drill drift was 0.026″; a stationary drill and rotating workpiece exhibited 0.015″ drift; and when both the drill and the workpiece were rotating, drill drift was only 0.009″. It should be noted that results will vary due to many factors, including material, depth-to-diameter ratio and the specific tooling involved.

Dedicated deep hole drilling machines

Even with careful application of drill and workpiece counter-rotation techniques, typical machining centers – if equipped for counter rotation – usually do not have the alignment capabilities needed to consistently produce high-quality holes of 20:1 or greater depth-to-diameter ratio. Superior alignment is critical in maintaining concentricity.

In dedicated deep-hole drilling equipment, the machine base, rotating bearing groups and spindles as well as tool and workpiece supports are all designed with alignment as a first priority. Deep-hole drilling machines also emphasize control of other machining and environmental factors such as consistent temperature maintenance.

Some machines not originally engineered for counter-rotation operation can be retrofitted with a secondary counter-rotating group, but the alignment processes needed to make the arrangement work will be challenging and expensive. Additionally, a machine originally designed to employ counter-rotation will be manageable for nearly any operator. Dedicated deep hole drilling machines, for instance, include operator interfaces that provide detailed process information and maximize control over drilling parameters to enable accurate, efficient and repeatable production.

Basic application guidelines

Every deep-hole drilling application is essentially unique. However, general application guidance for counter-rotating operations includes allowing one-third of the total drilling speed to come from workpiece rotation and two-thirds from the drill. Operating parameters can then be adjusted to maximize drilling speeds and accuracy.

Such counter-rotation techniques provide a way to achieve accuracy and production requirements in deep-hole drilling and are especially effective when drilling holes of 40:1 depth to diameter ratios or more. Counter-rotation generates higher levels of concentricity that enable use of optimal feed rates while also extending tool life. The result is production of more parts per hour with fewer tool changes.

08

Jun

Make Better Molds – Mill Better, Drill Faster

Mold making isn’t easy. There are many intricate challenges that include: highly complex geometry with 2D and 3D features, managing a wide range of part sizes, and short lead times on small quantities and new designs with no room for error. Compounding these challenges is the pressure to keep up with the rapid pace of demand and technology.

But there’s a way to overcome those obstacles: Do better work with technology designed specifically for complex mold making.

Our USC-M series Milling and Drilling Centers allow you to drill faster and mill better with a single machine and fewer setups. These Milling and Drilling Centers meet the challenges of milling and gundrilling all types of metals with either a single universal combination spindle or dedicated milling and drilling spindles. Utilizing high performance spindles that provide exceptional rigidity and power transmission, these machines deliver high-torque milling capability for aggressive metal removal and shorter cycle times. Additionally, 5-axis positioning enables mold manufacturers to tackle complex geometries with exacting precision in a single setup.

Many manufacturers claim to provide milling and drilling in a single machine, but the truth is those hybrid machines neither mill nor drill well enough to make a significant difference in either operation. In effect, one process is an afterthought of the other. Our USC-M series, however, was designed from the beginning to be a single machine with superior milling and drilling performance and accuracy. State-of-the-art milling technology is embedded into a machine that has the power, thrust, speed and process monitoring competitors thought would be difficult to attain, or simply not possible.

In addition to superior quality and accuracy, the pay-off for single setup milling and drilling is efficiency and an improved bottom line. Mold makers cut delivery times to their customers with faster setups and production along with reduced overall labor costs. Once they move away from mold making operations with two machines, most of our customers find they can’t afford to manufacture without a USC-M-series Milling and Drilling Center.

The benefits of milling better and drilling faster with USC-M series machines do not stop at the spindle. There are intangible benefits as well. UNISIG USC-M series Milling and Drilling Centers allow mold manufacturers to approach their work differently and explore different approaches to mold making. With the entire manufacturing process streamlined, customers find their engineers and design teams enjoy more freedom and flexibility with the expanded capabilities. Finishing and assembly are faster because the design is more efficient, and manufacturers can do things effortlessly that were a struggle previously.

Ultimately, it’s about setting the bar high and keeping it there. UNISIG sets a standard looked up to by the competition. It’s a state-of-the-art mindset that takes mold finishing to a new level with a machine that allows you to mill better and drill faster.

Learn more about UNISIG solutions for Mold manufacturing.

25

Apr

Effective Medical Instrument Gundrilling

Most conventional machine tool OEMs can help medical manufacturers produce highly complex and precise components such as surgical implants and tools. However, only an experienced and capable gundrilling machine OEM with a deep understanding of the challenges of stringent medical part drilling requirements can supply a truly effective solution.

For today’s medical parts, UNISIG makes impossible holes possible with reliable, highly productive and automated gundrilling processes. Such solutions allow medical manufacturers to overcome the challenges of medical parts and meet demands for higher volumes and cost reductions, while they also improve part quality and ease the pressures of labor issues where there’s either not enough of it or it costs more.

Our combination of integrated solutions and technical expertise cures your medical gundrilling headaches and allows you to produce very difficult holes, especially when dealing with:

  • Small holes with extreme depth-to-diameter ratios and tight tolerances
  • Difficult materials such as stainless steel, Inconel® and titanium
  • Thin-walled parts
  • Irregular OD parts that require multi-step operations

Not just any gundrilling system provider can drill the impossible hole. It takes a commitment to research, continuous improvement and collaboration. In fact, having an OEM to collaborate with you to solve complex problems can give you the confidence to incorporate gundrilling into your medical part production and use it to its full potential.

Once up and running, your in-house gundrilling capabilities will eliminate the hassles and extended lead times associated with outsourcing this work. Plus, when paired with Swiss-style turning machine cells often used in medical part production, in-house gundrilling will help improve throughput.

Overcoming the challenges of gundrilling medical parts is only half the battle. The other half requires continuous, reliable precision for thousands upon thousands of parts – and for the entire life of your gundrilling machine. At UNISIG, we consistently achieve those tight tolerances with our UNE6 series machines engineered with the utmost precision in mind, our specialized workholding for medical instruments and intelligent machine controls.

Well-targeted automation solutions can further enhance the benefits of gundrilling, especially in terms of process consistency and stability while also increasing the output of existing workforces. For many medical shops, automation is a game changer – and can provide the means for survival against the competition as well as a sustainable path to growth and profitability.

UNISIG’s automation-ready gundrilling machine design ensures a solid foundation for reliable, process-wide automation. Additionally, flexible workholding configurations such as our lantern chuck and other peripheral components make robotic integration even easier for medical gundrilling applications.

While automation helps ease labor issues, today’s medical part manufacturers still face numerous challenges, from stiff competition and constantly increasing production demands to cost control. However, drilling deep holes in tough medical components is one industry challenge that is forever improved thanks to UNISIG, a company that makes drilling the impossible holes possible.

07

Mar

Our proven process:
How UNISIG leverages experience and expertise to solve customer challenges

For over 40 years, we’ve helped our customers achieve success in deep hole drilling, providing them with the machines, automation and support they need to be competitive and profitable.

We have found that the initial energy we and our customers spend at the beginning of a quoting process pays off throughout the entire project, from inception to installation. We take a systemized approach not only during this critical phase but also throughout the entire sales process. This ensures there are no surprises and that our customers know exactly what they can expect when starting discussions with UNISIG about their gundrilling and deep hole drilling needs.

This is our approach at UNISIG:

1.) We listen to our customers, ask questions and understand what they need.

This may seem obvious, but often the temptation is there to just skip to a quote because we think we know what is needed after a brief discussion. Sometimes that is true, when the application is straightforward and familiar, or it is something we have a packaged solution for.  We always try to make the quoting process quick and efficient, but there are times when the application deserves a more in-depth conversation. Our salespeople and engineers listen very carefully and often pick up on small details – a specific tolerance, material condition, process requirement or a future need for flexibility – that may change our recommendations.

When it makes sense, our experienced sales team or engineers will visit a customer to see what is needed firsthand. Whether a site visit or just a virtual meeting, this initial investment of time to clarify the need saves the customer money and provides them a truly valuable solution.

2.) We first identify a standard solution from our product line that can be applied at the lowest cost and shortest delivery possible.

At UNISIG, our product development mindset is to systemize solutions from our experience in many different industries, make them automation ready and embed application flexibility whenever possible. We invest millions of dollars annually in our product line and related spare parts, giving us a strong starting point for new applications. Our standard product line encompasses much more than machines, including standard automation, workholding, accessories and tooling that we can offer as part of the solution.

Once we have identified a standard machine as a starting point, our engineers seek out smart, practical ways to meet the customer’s application needs. The goal is to innovate within the machining operation planning, work holding or automation, as opposed to engineering a completely special solution without first exhausting opportunities to solve problems with standard products.

For our customers, this approach provides them a reliable, standard machine that can be used for many years and that has the built-in flexibility for easy re-tooling to adapt to future needs.  For us, initially working within the boundaries of our catalog cultivates new ideas that can then be applied to improve our standard products as well as help us direct future research and development budgets.

 3.) If a standard solution isn’t available, we consider a customized solution and we stand behind it.

UNISIG is very good at building customized machines, and we do so often. Once we and our customers agree that a special solution is needed, we move forward with a great deal of confidence and experience. We start by evaluating how we might approach the design using standard modules or proven concepts, thus eliminating long debug cycles and/or high costs. Then we use our mechanical and electrical engineering disciplines to virtually test the new machine before we build it.

One of the key reasons our customers are confident moving forward with a UNISIG custom machine is that they know we will stand behind it and that we have substantial capabilities to ensure it always exceeds their production expectations. We approach these special projects with the mindset that a custom machine will be used for decades in production, which is why we provide the same documentation and long-term technical support for all our machines whether standard or custom.

4.) If a commodity solution is readily available, we recommend that rather than upsell a machine the customer doesn’t need.

We build machines that can gundrill or BTA drill deep holes that are impossible to drill on machining centers.  Even if it may be possible to drill some deep holes on a CNC machining center, our machines have the power, speed, dimensional accuracy, spindle density, coolant systems and process control that will improve productivity, tool life and reliability. Typically, though, when a customer comes to UNISIG with a specific part need, at that point they’ve most likely already struggled with a conventional machine and realized that a deep hole drilling machine is obviously the way to go.

However, our team knows how to identify whether or not an application would truly benefit from a UNISIG solution. When it wouldn’t, we will suggest viable alternatives. It’s not that we don’t want to sell a machine. But the fact is that our experience has shown that at some point the alternative-solution direction becomes obvious, and we want to make that apparent early on in the process so as to avoid wasting a lot of our customer’s time.

 

Our customers expect the best from us, and we believe that our proven process ensures we never disappoint. Our goal is to leverage our core values to serve our customers as best we can and build strong, productive relationships for years to come.

Please contact us to discuss your application.