What happens when a major power plant shuts down, critical infrastructure collapses, or a large manufacturer ceases production? Cascading effects that impact tens of thousands or even millions of individuals: the events radiate, like an earthquake from its epicenter, causing chaos in the form of unemployment, loss of product, service interruption, and significant delays – resulting in frantic work around with enormous associated costs. This does not have to happen and onsite machining is the potential solution.
Emergency and short notice situations are ideally solved by the use of onsite machining – engineers rapidly deploy portable machining tools to mitigate the disastrous impact of these scenarios – if not prevent their occurrence altogether. The seemingly miraculous function performed by onsite machining operations prevents downtime and the arranging of complicated transportation, stripping, and replacement of machines and parts. Mitigating such arrangements provides significant financial relief without sacrificing machine shop quality – whether on land, at sea, or in sub-sea environments.
Onsite – sometimes referred to as in-site, in-place, or field machining techniques are continually evolving, portable machining processes of additive and subtractive manufacturing. The bedrock of onsite machining rests in traditional machining practices which have origins in ancient antiquity. Onsite machining techniques continue to advance far beyond their foundational roots, however these early machining processes and their contributions – as well as limitations – are directly related to the success and value of onsite machining as an essential service in the modern world.
Table of Contents
Table of Contents
1 Machining Basics
The use of potter’s wheels, lathes, and bow drills date back thousands of years in human history, yet the freehand tool-path of manufacture and craftsmanship began to modernize in the late Middle Ages and during the Age of Enlightenment. With the stage set, manufacturers of goods from the 18th to 20th centuries built and improved machine tools – driven by several key industries such as textiles, clock making, firearms, bicycles, steam engines, automobiles, and aircraft. Early machining spurred the industrial revolution (e.g. John Wilkinson’s boring machine allowed accurately bored cylinders, the final step in making the first commercial engine), paving the way for interchangeable parts, mass production, and the whole of the modern world.
Traditional machining processes form the basis for many of the modern onsite machining procedures. These classic techniques include:
- Broaching – linear or rotary removal of material using a toothed tool
- Boring – enlarging of a previously drilled hole
- Drilling – cutting a circular cross-section in solid materials
- Milling – removal of surface materials with a rotary cutting tool
- Planing – use of a single-point cutting tool relative to a moving workpiece for cutting
- Reaming – precision smoothing and enlarging a previously formed hole
- Sawing – cutting through material using a hard toothed edge and forward motion
- Shaping – use of a single-point cutting tool relative to a stationary workpiece
- Tapping – cutting or forming the female portion of a mating pair
Onsite machining operations utilize these processes and many more with portable machining tools – though principally there are three primary machining operations: drilling, milling, and turning.
1.1 Drilling Operations
Involving a solid material and rotary cutting tool, drilling is an immediately accessible concept, often glanced-over as a constantly innovating and improving technique of machining. Advances in this seemingly straightforward operation are largely responsible for the United States Shale Revolution – an event that dramatically changed the global economic landscape regarding energy production.
There are many drilling processes, selecting an appropriate method depends on the material to be drilled and the type of hole desired, though the end result is almost always a round hole. Typical drilling operations employ a rotating tool, the drill bit, characterized by two or four helical cutting edges. The bit is fed parallel to its rotational axis into the material; swarf is removed by the fluting of the bit as the hole is drilled. Coolant or cutting fluid, may be added to aid in the removal of these chips, particularly when machining is conducted on metal or similar materials. Related to and sometimes accompanying drilling processes are those of boring, counterboring, countersinking, friction drilling, and reaming.
1.2 Milling Operations
Milling, as it relates to modern machining practices, replaced the older technique of rotary filing – both actions involve using circular or rotary cutters to remove material from a workpiece. Milling is a versatile process with a wide variety of possible approaches, depending on the direction, axes, pressure, and cutter head speed, and can be applied on virtually any scale. This degree of variability allows operators to achieve high precision tolerances on a wide variety of materials.
The process of milling can be achieved with several machining tools and the selection of an appropriate milling cutter, which is a rotary tool comprised of multiple cutting surfaces. Depending on the workpiece material, rate of material removal, and desired finish, a specific cutter is selected. The operation commences as the cutting tool is advanced perpendicular to its rotational axis, removing material through small, repeated cuts.
Though there are many functions milling can serve, operations are usually classified as face milling or peripheral milling. Face milling is employed to create flat surfaces or flat cavities into the workpiece, while peripheral milling is utilized to cut gear teeth, slots, threads and the like.
1.3 Turning Operations
Congruent with drilling and milling, the process of turning is among the oldest of machining techniques. Turning operations normally involve the use of a lathe to rotate the workpiece while a cutting tool, usually a single-point cutting tool, is applied. While turning, the cutting tool moves on as many as three axes of motion to create the desired diameters or depths. Though simple, this process is capable of producing complex figures that are conical, curved, straight, or grooved by removing chips of material from the workpiece.
Using a lathe and turning techniques allow operators to perform machining tasks similar to those of drilling and milling. Turning applies not only to the external surface of a workpiece, but to the internal surface, as a type of drilling, boring, reaming, or threading.
2 Onsite Machining
One of the most incredible advancements since the Machine Age, responsible for keeping the engine of the world turning, is that of on-site or in-situ machining. These onsite machining techniques use specialized, portable machines and workshops to perform the timely, essential repairs or modifications to facilities and equipment with little if any notice.Modern industries thrive on continuous, rapid production of goods and services to meet the tremendous demands of the global market.
When these products and services come to a halt for any length of time, a cascade effect ensues. Providers and producers temporarily cease working, logistics must be reworked, and the customers are left with increased prices or forced to turn elsewhere to meet their needs.The magnitude of these effects largely depends on the duration of the shutdown. The goal of onsite machining is to reduce downtime to an absolute minimum – many onsite machining techniques completely eliminate downtime (e.g. hot tapping).
Given the focus on portability, there is temptation to assume a lack of quality – after all, portable technologies such as smartphones lack the processing power of a traditional, stationary computer. The natural inclination is to apply similar modes of thinking to in-situ machining services. Contrary to this common and intuitive dichotomy, onsite machining retains the strengths of a stationary workshop while providing solutions in the field which are impossible to carry out with a machine shop.
The nature of onsite machining promotes novel and inventive engineering solutions while carefully observing the foundational aspects of machining. Traditional machining techniques are ingeniously adapted using modern principles of miniaturization, while advances in material sciences allow for the creation of portable machine tools with maximum portability and utility. Ultra-precise measuring using electronic, laser, or mechanically based portable tools – in combination with purpose built software – can match or exceed the accuracy of standard coordinate measuring machines (CMM) without any of the physical limitations associated with a stationary CMM.
2.1 Innovative Adaptation
The need to solve pressing, immediate operational concerns is the genesis of onsite machining practices, an origin which stretches back in history to the late 1800s. Engines onboard locomotives and warships would require onsite reboring of cylinder heads or crankshaft and journal machining. Late 19th century military arsenals were maintained and repaired by these same in-situ machining processes – a role that became essential during the Second World War. Portable machine tools and in place machining techniques have continually advanced, without hesitation, integrating the latest cutting edge technologies for ever more precise, portable, and effective operations.
The effectiveness of these techniques is rooted in their ability to negate downtime and massive transportation projects, while ensuring complete repairs or modifications in the shortest possible time span. Engaging the operations on location, without the need for disassembly, stripping, and transport logistics that might otherwise be required, calls for innovative and customizable solutions. Portable machine tools are often designed with a particular application in mind (e.g. cold cutting, hot tapping, trepanning). Custom in-house fabrication of portable machine tools is a routine phenomenon, often necessary for meeting the nuanced requirements of a given onsite machining operation – though numerous manufacturers of machine tools exist within the industry.
Efficiency and precision are the hallmarks of any on-site machining operation, as they are designed to shorten the timescale associated with costly repairs. The failure of even a single component in an industrial production facility can halt production for lengthy periods of time, as traditional methods of disassembly and transport would dictate. Though pioneered for circumstances requiring immediate solutions, the benefits of onsite machining extend far beyond urgent repairs. Anticipated maintenance and repair operations are advantaged by in place machining, on the basis of maintaining the highest degree of efficiency possible (or simply continued operation) for a given facility, nullifying complicated and time consuming transportation and logistics contingencies.
Removing the physical, spatial constraints of a machine shop allows for machining operations of a peculiar and sometimes fantastic nature. A simple, portable magnetic base drill allows for onsite machining with the precision and power of a stationary drill press – whether upside down, at odd angles, or operating in subsea conditions. The very compact cold cutting machine is a highly portable machine tool, designed to cut and bevel piping and pipelines without generating heat or sparks, which perfectly demonstrates the innovative use of materials and methods common to onsite machining practices.
2.2 Onsite Machining Solutions Across Multiple Industries
Hundreds of industries make everyday use of onsite machining – whether the refurbishment is scheduled or unexpected. An enormous range of scientific, industrial, military, and domestic industries rely on the large variety of in place machining techniques to continue their operations.
Onsite machining is routinely used for these sites and industries:
- Aerospace and Defense
- Aluminum and Steel Production
- Engine Power and Propulsion
- Fossil, Nuclear, and Hydroelectric Power
- Marine/Maritime Vessels
- Material Production and Manufacturing
- Moveable Structures
- Mining and Aggregates
- Nuclear Decommissioning
- Oil and Gas
- Onshore and Offshore Infrastructure
- Packaging and Paper
- Port Facilities
- Pressure Vessels
- Wind Power
Eliminating logistical headaches and reducing downtime equates to significant financial savings for those who call on the expert teams available for onsite machining. Far from being a compromise to standard techniques, these technical solutions are the highest quality available, designed to solve the toughest problems that present the most demanding tolerance requirements.
The portable and adaptable nature of on-site machining makes it well placed for solving difficult scenarios across industries, that would otherwise be impossible – stated another way – onsite machining is the miracle worker of the modern world. Though in place machining holds a position of high esteem within the modern, mechanized world, each of the dozens of techniques employed requires a number of considerations for equipment, location, and on-site variables to ensure a swift and efficient procedure.
2.3 Readying for Onsite Machining Operations
Preparing for an onsite machining operation falls to the experienced engineers, machinists, and crew members, who evaluate site conditions and requirements with the client. Appropriate consideration is given to the site, job requirements, safety, and standards that will govern the operation. Case by case considerations are essential to the process of onsite machining; classic machining techniques such as drilling, milling, and turning can be applied in a myriad of ways, though one site (e.g. pipeline cutting) may call for a particular approach – cutting with or without heat.
Industries often differ greatly in the techniques and tools required for onsite machining. From one industry to the next, safety concerns, work materials, and specific tolerances can vary considerably. These variances are fluently accommodated by skilled and experienced crews who are familiar with a broad range of industry standards.
Safety concerns are a primary consideration for onsite machining operations, and may vary from site to site as much as tools and techniques. Routine maintenance operations such as flange facing or flange milling – the process of machining flange mating surfaces to form a leak-proof seal on assembly – carry very different concerns from that of hot tapping, for example. Hot tapping is the onsite machining process that ties into live a pressure vessel or pipe system. The safety precautions taken during a hot tapping operation are extreme by comparison – given the pipeline or pressure vessel may contain combustible or hazardous materials – as the site is much less forgiving. Regardless of the particular onsite machining operation, detailed planning and meticulous execution must be observed from start to finish. As the decades have advanced, electronic technologies have significantly aided both planning and executing onsite machining operations.
Onsite measurements were initially confined to mechanical means; rapid innovations, in several technology oriented disciplines, have created ultra-precise and portable measuring equipment. Onsite inspection, measurement, and alignment processes achieve degrees of accuracy previously thought impossible with modern tools. In-situ measurements are collected using miniaturized electronic, optical, and laser instrumentation. The resulting data is compiled, recorded, and processed by specialized computer software. These techniques meet or exceed the standards of a stationary coordinate measuring machine. Modern technological advancements continue to dramatically change the preparatory and operational phases of onsite machining. Numerical control machining has revolutionized machining as a whole, while 3D printing (a form of additive machining) has the potential to define the next era of manufacturing, production, and repair.
3 Automated Onsite Machining
Numerical control (NC) machining is a form of automating machining, which has its roots in the 1940s and 50s technology of punched tape. NC machining, though useful to begin with, proved a quantum leap forward in both additive (3D printing) and subtractive manufacturing when augmented by analog – and later digital – computers. This form of automated machining necessitates minimal involvement from a manual operator. Mills, lathes, cutters, electric discharge machining, drills, grinders, submerged arc welders, and dozens of other machining processes are easily automated by this powerful and efficient advancement in machining technology.
3.1 Computer Numerical Control (CNC) Onsite Machining
Far outstripping the productive capability of fabricated pattern guides and manually controlled machining, modern CNC machining combines several technologies to machine workpieces without the aid of a manual operator. A maneuverable, motorized tool and platform are controlled by a computer processor. Computer aided design (CAD) files are translated into various code formats, which the CNC machine executes to machine the workpiece material.
CNC machining is commonplace in modern industrial manufacturing; as the use of NC machining has spread, the ability to program and control portable machine tools has increased. Virtually any industrial process involving a series of movements and operations can be guided by CNC systems. Onsite CNC machining operations include:
- CNC Boring
- CNC Cutters (Water Jet, Plasma, etc.)
- CNC Drilling
- CNC Finishing
- CNC Grinding
- CNC Lathes
- CNC Milling
- CNC Submerged Arc Welding
3.2 3D Printing
3D Printing is a computer controlled machining process used to create three dimensional objects by adding material together, usually one ‘sheet’ or layer at a time. Though limited to a narrow range of applications in its infancy, 3D printing has reached astonishing levels of precision machining with a broad array of materials.
Using computer aided design (CAD) files and digital 3D models, this type of additive manufacturing can produce minutely detailed shapes, parts, and work pieces. Traditional 3D printing is closely associated with fused filament fabrication, using plastics and polymers for manufacturing.
The growing use of metal powder bed fusion indicates the transformative possibility of reliably printing metal parts with precise tolerances. It is increasingly likely that this technology will receive extensive use in the near future of onsite machining processes.
4 Onsite Machining: Future Tech
CNC machining and 3D printing are revolutionary technologies in their own right, yet are facing even more recent technology developments. As technology improves, the rate of technological development improves; rather than additive increases – as those throughout most of history were – current technology multiplies and momentum compounds. This rate of growth is predicted to exceed multiplicative growth, and venture into the territory of exponential increase – with the advent of generative, era-defining, sciences such as nanotechnology and robotics.
Robotics and nanotechnology are hotly debated topics in STEM and medical fields for several reasons – primarily because of their nature as radically transformative technologies with near limitless application. A mere decade ago these fields were largely confined to theoretical discussions and work of science fiction; present day industries are being redefined by the introduction of these technologies, though they are still in relative infancy. The ‘future tech’ of robotics and nanotechnology are actively employed in present day machining processes around the globe – their role is certain to dramatically reshape many fields of human endeavor – direct involvement in the processes of onsite machining is a short step away.
4.1 Robot Machining
Known for their versatility, complex machine paths, typically large workspaces, and rapid production, robots have earned a place in industry. Industrial manufacturing has used robots for more than a decade for several tasks, namely: assembly, handling, machine tending, machining, spray painting, and welding. There can be no doubt that robots will continue to see broad usage in industrial applications, yet there is a snag.
Machining applications involving relatively soft materials (foam, plastic, wood, some light metals) are easily worked by robots. Harder materials (aluminum alloys, bronze, copper, ceramics, steel, titanium, etc.) result in significantly reduced precision. The lack of rigidity or stiffness of a robot – when compared with traditional machine tools – is a distinct disadvantage, as the tool moves upon contact with harder materials. The resulting inaccuracies of machining on hard materials is a limitation for robots, when contrasted with traditional machine tools.
Robots encounter difficulties when faced with harder materials, yet still present a number of advantages in the realm of machining. The robot can be moved from one task to another, performing milling, drilling, and turning operations while utilizing 6 degrees of freedom (CNC machines generally have 3 to 4). Complex designs are much easier to achieve with a robot, provided the materials are of an amenable hardness.
Confined primarily to machining for softer-material industrial applications, robots will require further refinement to work in many onsite machining applications. The ability to handle sophisticated designs and maintain flexibility is a valuable and highly sought after aspect of robot machining, sure to draw the eye of many talented engineers and developers for future use.
4.2 Ultra-Precise Machining with Nanotechnology
Nanotechnology involves engaging matter on the nanoscale – in the range of 1 to 100 nanometers. A nanometer is one billionth of a meter; for comparison, a human hair has a width of approximately 80,000 to 100,000 nanometers. A single atom of Gold is nearly one third of a nanometer. While the scale is difficult to imagine, the reality is that scientists and engineers have rapidly progressed the ability to engage materials in this unimaginably tiny domain.
Ultra-precise machining at the nanoscale has been possible for at least a decade and is now employed in several industries: automotive, biotechnology, electronics, medical, ultra precision optics, and watchmaking. CNC Diamond Turning Lathes – with up to 5 axes – can perform milling, turning, grinding, and finishing on the nanoscale. These incredible machines work with a wide variety of materials and are even capable of achieving finishes on a sub-nanometer scale. Though nanoscale machining may be a considerable distance from the front lines of onsite machining practices, it’s only a matter of time before these techniques are applied to a much wider variety of materials.
5 Typical On Site Machining Services At A Glance
- Alignment and Measurement
- Annealing and Hardness Removal
- Cold Cast Iron Repair
- Cold Cutting
- Cold Tapping
- Crankshaft Repair and Machining (Crankshaft Turning)
- Onsite CNC Machining
- Deep Hole Drilling
- Onsite Drilling
- Flange Facing
- Hot Tapping
- Journal Turning
- Key Cutting (Shaft Key Cutting)
- Leak Sealing
- Line Boring and Reaming
- Onsite Milling
- Stud Removal
- Tyre Grinding
- Tube Testing
- Onsite Valve Repair
- Onsite Welding
6 Mechanical Miracle Worker of Today and Tomorrow
Advances across multiple fields of technology and science allow for incredibly advanced highly portable machine tools, capable of repairing and reviving the worn components and machines essential to day to day operation in virtually every field of modernized, scalable human endeavor. Performing this service leaves little doubt that onsite machining will remain an absolute staple of industry for the foreseeable future – just as classic machining processes date back to the dawn of historical records.
Onsite machining services will only increase in safety, efficiency, and effectiveness as science, technology, and engineering continue to make advances. Leaps in technology, such as those of CNC machining and 3D printing demonstrate this. Future technologies rest on the threshold, awaiting further development and showing great promise.
6.1 Further Reading
For More Onsite Machining Processes
Hot Tapping – Successful Pipeline Tapping
Hot Tapping and Line Stopping Overview
Mirage Machines Portable Performance Blog
Robot Machining and More – RoboDK Blog
6.2 Related Videos
The History of Numerically Controlled Machine Tool – NC and CNC
The 1751 Machine that Made Everything