CNC waterjet art - Control Waterjet Cutting use state-of-the-art technology to cut materials as diverse as aluminium to granite and glass. Used throughout industry as a method of cutting accurate and fine profiles waterjet technology is still relatively unheard of in the art and design world with only a few pioneering companies proactively offering their services to the craft and design market. One such company is Control Waterjet Cutting. Based in Chesterfield, Derbyshire, Control Waterjet has developed a connection with some leading members of the art and design community through their ability to meet the needs of the artist to maintain the individuality of the creation with the science and engineering that surrounds waterjet technology. While artists strive to harness new technologies to produce their creative visions many are constrained by the mechanical limitations of machines, processes and skill of the engineers. The challenge, inevitably, lies in the relationship between the artists’ vision and the skill of the engineers to translate that vision. Commenting on the connection between the artist and the use of technology, Liz Lemon, a public art sculptor and artist based in Nottingham said, “It is important that the work that is produced retains the individuality that has been incorporated into the design by the artist. This is very important to me. My work, such as the Bolsover Gateway design, includes fine drawings of birds, prehistoric dragonflies and signatures cut out of the steel panels in the gate. This required very delicate craftsmanship. Control Waterjet Cutting’s approach enabled the work to maintain the intricacy and individuality that I had envisaged.” Waterjet technology is a computerised cold cutting technology that can cut most materials such as marble, granite, porcelain, ceramic, vinyl, glass and all metals. It is a clean process that does not heat, harden, or distort metals and is so gentle it can cut glass. A key benefit of the technology is that it can be used for cutting composites and plastics that cannot tolerate heat, mechanical damage or delimitation. This gives the artist the freedom to choose a wide range of mediums. Anything that can be drawn on a computer can be cut by waterjet. Although the skill in the art and design market is the engineers’ ability to translate the artistic vision of the designer or architect, sometimes a pencil drawing or people’s signatures, through a cold programming medium into a sculpture or art form. Waterjet cutting has significant advantages over competing cutting methods, such as routers, plasma torch, laser cutting and electrical discharge machining (EDM). It can cut through materials considered un-machinable by conventional cutting methods. Waterjet cutting technology also has cost advantages over traditional methods. Depending on the material, thickness and intricacy of the cut, the savings compared to traditional cutting methods can be substantial. And many materials like stone, porcelain, and stainless steel cannot economically be cut into complex shapes in any other way. Underlining the unique abilities and application of Control Waterjet Cutting’s techniques, Stewart Ellis, Managing Director of J C Balmforth, a midlands based pattern making and casting company with a long history and heritage, said, “We had a very intricate Melting Clock sculpture that a leading designer wanted us to cast as a limited addition in aluminium. It is a complex design with lots of distortion and cracking. The cutting on the face and body, that gives the cracking effect, presented us with a challenge. We could not use laser cutting due to the thickness of the materials. We could have cut by hand but this would have been very costly. After investigating the alternatives we commissioned Control Waterjet Cutting. They developed the process to cut the clock faces and produced samples. The cutting was very fine and gave us the perfect solution.” Reinforcing Stewart’s findings Johnny White, renowned public and kinetic sculptor said, “We settled on waterjet cutting because of its ability to produce very fine cuts in thin material without distorting the material due to heat being generated. This is very useful as it means we can use the process for developing the most complex designs. Waterjet cutting is a relatively new process with many advantages. I have been using other cutting processes for the past ten years but have moved to waterjet cutting because of the quality of finish and degree of control it offers. When cutting aluminium there is also the added benefit that the cut edge is not porous, so a good seal is achieved when it is anodised. In addition it leaves softer edges that are more aesthetically pleasing with the added bonus that they do not have to be de-burred. We always use Control Waterjet Cutting for our work because of their ability to translate our ideas into practical finished work. They are also very service focused.” he added. The waterjet cutting process is an environmentally friendly solution to many complex cutting operations. The process is clean, does not create dust, grindings, chips, or chemical air pollution. Waterjet carries away the eroded material, practically eliminating dust and does not generate pollutants and fumes associated with other cutting methods. Cutting oils or emulsions are not needed with this process. Explaining why Control Waterjet Cutting specialises in the art and design market, Claire Smith, Managing Director of Waterjet, said, “We have developed this market through understanding the needs of our clients. When there is a difficult and complex job with very fine cutting and technical problems we will provide a no fuss solution. The challenges can be technical with an innovative approach to overcoming the production problems relating to a material or cutting form. We feel our company’s approach to working with our clients’ and the high service levels we give is our edge in this market.” If you have a complex cutting requirement or would like to have further information regarding Waterjet’s capabilities please call Ian Macpherson, Sales Director of Control Waterjet Cutting, on 01246 284000.
Water jet cutter
A water jet cutter, also known as a waterjet, is a tool capable of slicing into metal or other materials using a jet of water at high velocity and pressure, or a mixture of water and an abrasive substance. The process is essentially the same as water erosion found in nature but greatly accelerated and concentrated. It is often used during fabrication or manufacture of parts for machinery and other devices. It is the preferred method when the materials being cut are sensitive to the high temperatures generated by other methods. It has found applications in a diverse number of industries from mining to aerospace where it is used for operations such as cutting, shaping, carving, and reaming.
History
In the 1950s, forestry engineer Norman Franz experimented with an early form of water jet cutter to cut lumber. However, the technology did not advance notably until the 1970s when Mohamed Hashish created a technique to add abrasives to the water jet cutter. This and other concepts allowed Yih-Ho Michael Pao to develop commercial "ultrahigh-pressure waterjets and abrasive-waterjets into better tools for industrial cutting, drilling, and milling, especially for the flexible factory automation." Today the water jet is unparalleled in many aspects of cutting and has changed the way many products are manufactured. Many types of water jets exist today, including plain water jets, abrasive water jets, percussive water jets, cavitation jets and hybrid jets.
Operation
In the 1950s, forestry engineer Norman Franz experimented with an early form of water jet cutter to cut lumber. However, the technology did not advance notably until the 1970s when Mohamed Hashish created a technique to add abrasives to the water jet cutter. This and other concepts allowed Yih-Ho Michael Pao to develop commercial "ultrahigh-pressure waterjets and abrasive-waterjets into better tools for industrial cutting, drilling, and milling, especially for the flexible factory automation." Today the water jet is unparalleled in many aspects of cutting and has changed the way many products are manufactured. Many types of water jets exist today, including plain water jets, abrasive water jets, percussive water jets, cavitation jets and hybrid jets.
Benefits
An important benefit of the water jet cutter is the ability to cut material without interfering with the material's inherent structure as there is no "heat-affected zone" or HAZ. Minimizing the effects of heat allows metals to be cut without harming or changing intrinsic properties.
Water jet cutters are also capable of producing rather intricate cuts in material. With specialized software and 3-D machining heads, complex 3-D shapes can be produced.
The kerf, or width, of the cut can be changed by changing parts in the nozzle, as well as the type and size of abrasive. Typical abrasive cuts are made with a kerf in the range of 0.04" to 0.05" (1.016 to 1.27 mm), but can be as narrow as 0.02" (0.508 mm). Non-abrasive cuts are normally 0.007" to 0.013" (0.178 to 0.33 mm), but can be as small as 0.003" (0.076 mm), which is approximately the width of a human hair. These small jets can make very small detail possible in a wide range of applications.
Waterjets are capable of attaining accuracy of 0.005" (0.13 mm), and repeatability of 0.001" (0.03 mm).
Water jet is considered a "green" technology. Water jets produce no hazardous waste, reducing waste disposal costs. They can cut off large pieces of reusable scrap material that might have been lost using traditional cutting methods. Parts can be closely nested to maximize material use, and the water jet saves material by creating very little kerf. Water jets use very little water (a half gallon to approximately one gallon per minute depending on cutting head orifice size), and the water that is used can be recycled using a closed-looped system. Waste water usually is clean enough to filter and dispose of down a drain. The garnet abrasive is a non-toxic natural substance that can be recycled for repeated use. Garnet usually can be disposed of in a landfill. Water jets also eliminate airborne dust particles, smoke, fumes, and contaminants from cutting materials such as asbestos and fiberglass. This greatly improves the work environment and reduces problems arising from operator exposure.
Versatility
Because the nature of the cutting stream can be easily modified the water jet can be used in nearly every industry; there are many different materials that the water jet can cut. Some of them have unique characteristics that require special attention when cutting.
Materials commonly cut with a water jet include rubber, foam, plastics, composites, stone, tile, metals, food, paper and much more. Materials that cannot be cut with a water jet are tempered glass, diamonds and certain ceramics.
Water jet cuts are not typically limited by the thickness of the material, and are capable of cutting materials over eighteen inches (45 cm) thick. The penetrating power of these tools has led to the exploration of their use as anti-tank weapons but, due to their short range and the advent of composite armour, research was discontinued.
Availability
Commercial water jet cutting systems are available from manufacturers all over the world, in a range of sizes, and with water pumps capable of a range of pressures. Typical water jet cutting machines have a working envelope as small as a few square feet, or up to hundreds of square feet. Ultra-high pressure water pumps are available from as low as 40,000 psi (276 MPa) up to 100,000 psi (689 MPa).
Process
There are six main process characteristics to water jet cutting:
- Uses a high velocity stream of abrasive particles suspended in a stream of Ultra High Pressure Water (30,000 - 90,000 psi) which is produced by a water jet intensifier pump.
- Is used for machining a large array of materials, including heat-sensitive, delicate or very hard materials.
- Produces no heat damage to workpiece surface or edges.
- Nozzles are typically made of sintered boride.
- Produces a taper of less than 1 degree on most cuts, which can be reduced or eliminated entirely by slowing down the cut process.
- Distance of nozzle from workpiece affects the size of the kerf and the removal rate of material. Typical distance is .125".
Temperature is not as much of a factor.
Edge quality
Edge quality for water jet cut parts is defined with the numbers 1 through 5. Lower numbers indicate rougher edge finish; higher numbers are smoother. For thin materials, the difference in cutting speed for Quality 1 could be as much as 3 times faster than the speed for Quality 5. For thicker materials, Quality 1 could be 6 times faster than Quality 5. For example, 4" thick Aluminum Q5 would be 0.72 ipm (18 mm/min) and Q1 would be 4.2 ipm (107 mm/min), 5.8 times faster.
Multi-axis cutting
With recent advances in control and motion technology, 5-axis water jet cutting (abrasive and pure) has become a reality. Where the normal axes on a water jet are named X (back/forth), Y(left/right) and Z (up/down), a 5-axis system will typically add an A axis (angle from perpendicular) and C axes (rotation around the Z-axis). Depending on the cutting head, the maximum cutting angle for the A axis can be anywhere from 55, 60, or in some cases even 90 degrees from vertical. As such, 5-axis cutting opens up a wide range of applications that can be machined on a water jet cutting machine.
A 5-axis cutting head can be used to cut 4-axis parts, where the bottom surface geometries are shifted a certain amount to produce the appropriate angle and the Z-axis remains at one height. This can be useful for applications like weld preparation where a bevel angle needs to be cut on all sides of a part that will later be welded, or for taper compensation purposes where the kerf angle is transferred to the waste material - thus eliminating the taper commonly found on water jet-cut parts. A 5-axis head can cut parts where the Z-axis is also moving along with all the other axis. This full 5-axis cutting could be used for cutting contours on various surfaces of formed parts.
Because of the angles that can be cut, part programs may need to have additional cuts to free the part from the sheet. Attempting toslide a complex part at a severe angle from a plate can be difficult without appropriate relief cuts.
Content courtesy by Wikipedia.
