UNISIG B-Series deep hole drilling machines are capable of drilling to depths of 100 x diameter or greater. But with BTA drill tubes as long as 30 feet spinning at high RPMs, vibration is an inevitable side-effect which can derail the hole concentricity and degrade the surface finish – or worse.
UNISIG B-Series deep hole drilling machines are capable of drilling to depths of 100 x diameter or greater. But with BTA drill tubes as long as 30 feet spinning at high RPMs, vibration is an inevitable side-effect which can derail the hole concentricity and degrade the surface finish – or worse. This is routinely combatted through the use of vibration dampeners, installed at intervals along the length of the drill tube, to support the tube during drilling and reduce the effect of harmonic resonance or vibration.
Vibration dampening assemblies are comprised of heat treated components and precision bearings that clamp around the BTA drill tube (see durable tooling on website). Standard vibration dampeners are manually adjusted prior to drilling via tensioning locknuts on each end of a tapered collet, for a durable and cost-effective solution.
Hydraulic vibration dampeners offer the ability to adjust the dampening effect on the drill tube during drilling operations with an internal hydraulic piston. These dampeners, although a more complex system with a higher price point, offer multiple advantages over standard dampening assemblies:
Micro-adjustments to the clamping pressure are possible with hydraulic vibration dampeners, with finer control ability than the adjusting threads of a traditional dampener allow.
Repeatable clamping set points can be achieved, as the pressure gauge provides a readout to allow the documentation of set points for future setups.
Hydraulic vibration dampeners allow you to adjust the clamping pressure – or release – during the drilling operation. This is extremely helpful in deep-hole drilling operations because harmonics tend to change at different depth-to-diameter ratios, and workpiece material may have hard spots that change the vibration characteristics mid-operation. When multiple dampening devices are being used, this system also allows the release of pressure from individual dampeners when they are no longer needed.
No hand tools are needed to adjust the clamping pressure, allowing the operator to make adjustments quickly and easily.
Hydraulic vibration dampeners can be controlled with a manual screw pump or powered hydraulic unit. A manual pump is a lower-cost system, while still offering all the advantages listed above. For an improved ability to control and adjust the pressure on the drill tube, the dampening assemblies can be actuated by a central hydraulic unit. This allows the operator to make changes at the machine control, and pressure settings can become part of the program on CNC-equipped machines. This is the highest level of control – and repeatability – in vibration dampening technology that UNISIG has installed on B-Series deep hole drilling machines.
At every stage of manufacturing, there is an opportunity for automation. Unfortunately, many manufactures often let perceived barriers keep them from implementing complete machine or process automation. With this mindset, they end up limiting their productivity by automating only one or two aspects of the process or not automating at all.
Conversely, those manufacturers that instead approach automation with an open mind and focus on breaking through barriers that could potentially prevent automation are those that are capable of automating as many stages of manufacturing as possible. These shops consider automation to be a key part of their enterprise-wide strategy, one that encompasses everything from sales, engineering and materials flow to actual machining operations and quality control.
When it comes to automation, most of the time should be spent getting all other manufacturing steps under control. That means making sure machines are robot ready; manufacturing process are robust and reliable to function automatically; and that there are quality checks in place to prevent issues from permeating to other operations within the process. Plus, while eliminating these barriers to automation, shops will often realize that doing so has as much of an impact on productivity as would simply adding a robot.
For one UNISIG customer, careful review and implementation of automation and process optimization resulted in about 150% production increase over previous manual operations without increasing feedrates.
The shop’s recently added automated gundrilling process simplifies completion of large orders with long delivery schedules. Most of the shop’s workflow involves long-term contracts and multi-month purchase orders for 1,000 or more parts. That streamlined workflow thanks to automation makes production planning easy because the company can establish shipping dates and work backward to create the build schedule.
There are opportunities to automate most elements of a company’s manufacturing environment. The impact of well-targeted automation solutions maximizes the overall benefits of process stability and consistency as well as increased output than does simply adding another robot in production. These opportunities are often overlooked – or worse, the lack of automation in less obvious areas deters the integration of further conventional automation.
Before machining a part, for instance, enterprise resource planning (ERP) systems, CAM software and even tools for simulating machines all contribute to automation at the machining stage. The ability to program from engineering model files without having to export from engineering CAD files or filtering through old revisions is often an added bonus, and a welcome quality-of-life improvement from today’s CAD/CAM users.
Through simulation, manufacturers can verify programs to avoid crashes as well as to optimize the machining plan and eliminate unexpected events that impact quality. In turn, this unleashes the true performance potential of modern machine tools that may have otherwise gone unused. Bringing the entire machining process into the digital realm also creates the opportunity for a digital twin that can be stored as a record of the manufacturing process.
Digitally modeling more than the workpiece and tool, such as adding fixtures and machine components, creates new possibilities for improvement along with complete process optimization and further encourages the use of standard libraries beyond just cutting tools. Standardization of tool libraries that include more than dimensions, but also feed and speed tables by material type, for instance, eliminate the need for manually determining such parameters for every part application.
There are also a variety machine features that can contribute to a more automated workflow – including many things individuals wouldn’t ordinarily consider automation. Modular quick-change fixturing and off-line tool setting further automate and reduce setup time, for example. Likewise, in-process inspection cycles confirm part quality during production to ensure uninterrupted operations.
When considering the machine tool automation aspect, an automation-ready design is critical to provide a solid foundation for process-wide automation. For deep hole drilling machines, that starts at the core of a machine’s design with its axis plan and spindle movements.
Other automation-ready machine aspects include automatic doors for automation access, communication capabilities in the controls and sensors, and other features and capabilities specifically made to interface with or supplement automation.
In the case of deep hole drilling systems, a shop may manually load a part, but the machine’s underlying design allows it to automatically lift and nest a part into a fixture, set the tool offsets, drill a hole and send it back to the nest for unloading – all with perfect accuracy and repeatability.
For many companies that compete against low-cost offshore suppliers, automation often means survival, but more importantly, it provides a sustainable path to growth and profitability.
Prior to implementing it however, shops must focus on and eliminate or correct any preconceived barriers to automation they may have. In doing so, automation becomes a process and enterprise-wide initiative, from the engineering department and the production floor all the way to the shop’s machine tools.
UNISIG's production cell integrates our UNE 2-spindle gundrilling machine and UNR 2-spindle reaming machine with robotic automation. The cell leads into our R-2A rifling machine for steady, repeatable rifle barrel blank manufacturing at high production.
UNISIG’s production cell integrates our UNE 2-spindle gundrilling machine and UNR 2-spindle reaming machine with robotic automation. The cell leads into our R-2A rifling machine for steady, repeatable rifle barrel blank manufacturing at high production.
The cell includes automated tool handling and machine guarding. Effortless production is furthered with racking systems, inspection, and oil blowoff capabilities.
Match Grade Machine, a specialty manufacturer of standard and custom single shot rifle and pistol barrels, stands out in their industry for their exceptional accuracy and attention to detail, complimented with a proven record for fast delivery to customers' hands.
UNISIG Solution: Firearms Industry Production Cell
Match Grade Machine, a specialty manufacturer of standard and custom single shot rifle and pistol barrels, stands out in their industry for their exceptional accuracy and attention to detail, complimented with a proven record for fast delivery to customers’ hands. The reputation of their products, as well as their high level of customer service and responsiveness, is vital to their long standing success and brand integrity.
Dylan Sip, owner of Match Grade, is always conscious of opportunities to improve his company and advance their balance of brand and product values. Being able to offer top quality barrels, at a competitive price point, with the fastest lead times to market is what has earned them their place in the market. Continue reading ““Taking Control of Barrel Blank Production | Case Study”“
For deep-hole drilling, part-handling might be the most visible automation element, but it’s not necessarily the most impactful. Often, it’s internal process automation that yields the most significant results even with a manually loaded drilling machine.
BY ANTHONY FETTIG, CEO — UNISIG DEEP HOLE DRILLING SYSTEMS
For deep-hole drilling, part-handling might be the most visible automation element, but it’s not necessarily the most impactful. Often, it’s internal process automation that yields the most significant results even with a manually loaded drilling machine.
When it comes to automating deep-hole drilling, there are challenges unique to the process itself. These include fixturing complexities — where maintaining alignment requires elements such as guide bushings and tool supports not present in a conventional lathe or milling machine — and part attributes such as length and weight.
Long parts mean a long drilling cycle time, and maintaining production rates often requires multi-spindle, deep-hole drilling systems. Unfortunately, stopping a two- or four-spindle machine means two or four spindles sit idle until the parts are loaded and unloaded. So, in these instances, the more parts in the machine at one time, the more automation can actually inhibit cycle time while the machine is running.
Solving this problem in multi-spindle machines requires internal automation to achieve the objectives of lean manufacturing and one-piece flow. In-machine loaders singulate processes so that even within a small four-piece batch you maintain one-piece flow. The operator or automation device puts in a part and takes a part out, and the machine does a bit of maneuvering inside to sequence those four parts in such a way as to minimize spindle downtime while maintaining upstream and downstream processes for one-piece flow. For instance, parts could be loaded onto a smart conveyor, indexed, and lifted into chucks for the drilling cycle before robotic unloading on the out-feed side so that there are no bottlenecks to a steady production flow.
Tool life management is another form of internal automation. Getting feedback to the machine enables the deep-hole drilling process to adapt or halt, if necessary, before tools and parts are damaged.
Tool life management is built into a machine’s control, and the machine senses torque thrust and coolant. Chip condition is usually the first indicator of wear, which would otherwise require an operator present to detect, so the machine actually monitors the process and can predict tools starting to wear and identify when they need to be changed. A tool life management system also can count distances drilled and the number of cycles, then prompt a tool change at the appropriate time.
That kind of in-machine automation smooths the path for external automation. As the process builds, highly standardized options for robot-ready machines such as an automatic door, workpiece-present sensors and programmable workpiece fixturing makes it easier to add a robot at a later date. These robot-ready machines also create efficiencies before they’re fully automated. Even with manual loading, the automatic doors and programmable clamping make the process more efficient.
In UNISIG’s experience, an embedded reamer tool changer enables manufacturers to manage significant throughput increases, even with an operator. With this technology, operators can maintain the pace of production loading the machine, while eliminating the task of inserting reaming tools for each cycle. This allows the operator to redirect efforts towards tasks such as additional quality checks and off-machine setups.