'Streamline Machining' depicts the benefits achieved from the new control system, software and mechanical developments resulting in up to 40 per cent faster machining cycles.
'Streamline Machining' is a new term adopted by Citizen for its latest generation of CNC sliding head turn/mill centres that depicts the benefits achieved from the new control system, software and mechanical developments resulting in up to 40 per cent faster machining cycles than could be achieved using the same program and tooling on the previous generation machines. At MACH 2006 on NC Engineering Stand 5262, the latest L20-VIII and K12 and K16 citizen machines will be demonstrating the benefits of these new levels of flexibility and the ability to cut with two tools simultaneously at the main and subspindle involving single 'one-hit' cycles. Central to streamline machining is the Citizen software development for the new control systems.

The low-cost Citizen K12 and K16 machines have a special version of the latest Fanuc 31i Series control and the L20-VIII an advanced Mitsubishi 700 control.

Both the K and L ranges can perform with the involvement of up to five-axes with full synchronisation of the main and subspindles, direct spindle indexing that is able to pre-select the reference point of the C-axes even while the spindle decelerates.

This saves valuable time against the previous generation control operating routines that required the spindle to be stationary before the protocol sequence could seek the reference point.

What has to be considered is that many of the Citizen cycles used at customers involve considerable C-axis spindle positioning for cross drilling and milling.

Both machine types have had rapid traverse rates increased by 60 per cent to 32 m/min with the added advantage that acceleration and deceleration rates are improved by a factor of 1.6 on each axis.

By utilising the new shockless acceleration/deceleration curves, each machine is now able to give greater machining consistency with extended tool life and improved levels of surface finish.

Also, as a tool enters a cut, it is now able to overlap with the exiting tool that once again saves non-productive time and reduces any likelihood of vibration or pick-up on a machined surface as the new tool engages with the workpiece.

A further significant factor is idle time reduction on the new machines, especially when thread cutting and tool changing.

Here, the ability of the control to read ahead, enables the pre-emption of simultaneous axis movements.

The Citizen L20-VIII with a 20 mm capacity by 200 mm machining length can carry up to 21 tools with nine driven.

In recent trials a 240 second machining cycle was reduced to 164 secs - a 29 per cent saving.

At a UK customer, Unicut Precision of Welwyn Garden City, an L20-VIII was able to reduce cycle times against a previous L20 installed in the works, by almost a third.

The K12/K16 with 12 mm (1/2 inch) and 16 mm capacity will carry 19 tools with eight driven and compared to the B12 Citizen machine replaced at Tenable Screw of Merton, a K16-VII was able to reduce the cycle time on one part from 55 secs to 36 secs, a 35 per cent saving on each part produced.

Subcontractor Stag currently utilises only half of its single- and multi-spindle auto capacity, as orders for large batches needed to justify their use are becoming increasingly scarce.
Subcontractor, Stourbridge Turning and Grinding (Stag), currently utilises only half of its single- and multi-spindle auto capacity, as orders for large batches needed to justify their use are becoming increasingly scarce, and those that remain tend to go overseas. Since 2001, CNC mill-turning machines, in particular multi-axis sliding-headstock lathes from Star Micronics GB, have been fulfilling contracts for smaller volumes much more cost-effectively. 'They can be set up quickly and are able to produce parts in one visit to the machine, eliminating manual second operations,' explained Stag director, Giles Pargeter.

'As a result, in four years we have reduced our shop floor staff from 23 to 14, which has resulted in significant savings and made us much more competitive.' Between August 2002 and December 2005, Stag invested in four sliding-head bar automatics of 32 mm capacity, one 20 mm machine and a 16 mm model, all from Star.

'After the first lathe was installed, I could not believe how much more profitable manufacture of components became compared with machining them on our cam auto's,' Mr Pargeter enthused.

'It opened up new possibilities for producing higher added-value components that we could not have entertained before.

Nearly all parts undergo prismatic machining operations using live tooling and are machined on the reverse end using the sub spindle.

'Whereas we were selling parts for a few pence at low margins, especially if they needed second operations, suddenly we were turning out complex components in one hit costing several pounds each and making good margins.' Unless a new component is obviously a sliding-head job, Mr Pargeter generally sets it up on a fixed-head lathe if the order is for a small quantity.

However, he estimates that a five-minute fixed-head cycle can typically be carried out on a sliding-head lathe in three minutes, owing to its faster axis travels and shorter tool movements.

He therefore sets up repeat jobs and longer runs on one of his Stars, provided that the component is under 32 mm diameter, as it almost always fulfills the contract more economically and can achieve tighter tolerances as well.

In this connection, he mentioned a square section drive shaft for an engine fuel pump that he machines on a Star SR-20RII to a total tolerance of 15 microns.

Despite the large batch sizes, the customer does not want to put this work overseas, as experience is needed when turning to leave an allowance for growth during subsequent heat treatment and finish grinding.

The manufacturer does not want to risk incorrect shafts from China or India delaying deliveries of its fuel pumps, whereas the supply is much more controllable if it is UK-based.

Many subcontract company owners and directors fear that by the time they retire, foreign competitors will have secured the work that remains in the UK, even the manufacture of highly complex and safety critical components, as the skill level and experience of overseas machinists improve further.

Mr Pargeter takes a more optimistic view of the future of UK subcontracting, however, noting that as components become ever more complex, often requiring design input by the company tasked with machining them, this favours domestic suppliers.

He also predicts that machine tools will become progressively faster and more capable, lessening the advantage of manufacturers in low wage economies.

In ten years' time, the level of wages in those countries will have increased as their citizens demand a higher standard of living.

The combined effect will be to markedly reduce the differential between prices quoted by UK and overseas subcontractors.

Stag is clearly planning its future based on this premise.

It invested £2 million during 2004 on new plant and larger premises more suitable to the smooth flow of production through to delivery of high precision components.

Three of the new Star sliders were delivered directly to the new factory, which runs around the clock, lights-out from 5.00 pm through to 8.00 am, six days a week.

Around 45 per cent of business is in the supply of hydraulic valve components for off-road vehicles, with the remainder spread across a wide range of industries including automotive, agriculture and construction.

Mr Pargeter plans to continue investing and growing the business.

He says that he finds it difficult to break into new customers these days, as most OEMs and first-tier manufacturers are reducing their supplier base and asking the best subcontractors to increase the work that they do.

So he is actively targeting his existing customers to build turnover, and with some success, having increased tenfold the monthly turnover with one manufacturer.

An outdoor lighting manufacturing has improved the appearance and functionality of their product by producing CNC prototypes whose higher accuracy makes it possible to refine their product to a higher degree. In the past, Architectural Area Lighting (AAL) produced prototypes of their lighting fixtures with hand tools but this was time-consuming and inaccuracies hindered the design process. So the company purchased a CNC router that produces prototypes from foam that match the computer aided design (CAD) files used to define the part within a few thousands of an inch. The CNC router typically takes only about 12 hours to produce the prototype and runs by itself without requiring operator attention. "Having an accurate prototype makes it possible to evaluate the design to a higher degree and also lets us validate the fit and functionality of the part," said Cory Landefeld, Product Design Manager for AAL. "The new router paid for itself in less than a year by drastically reducing the time and money we spent prototyping."

Architectural Area Lighting is a leading manufacturer of specification grade, outdoor contemporary and traditional style lighting fixtures. The company specializes in combining relevant aesthetic designs with superior lighting performance to ensure the quality of light matches the quality of the fixture. Some of the company’s typical lighting applications include commercial buildings, retail applications, downtown street lighting, educational facilities and sport complexes. AAL’s products include period and contemporary lighting, floodlights, steplights, wall sconces and bollards. The company design, develops and fabricates their products while die castings are produced by subcontractors.

The ability to design stunningly attractive yet highly functional designs is the key to their success. Using Ashlar’s Cobalt CAD software, designers have been producing increasingly sophisticated 3D geometries that have attracted the attention of architects, specifiers, engineers and building owners. The designers typically conceive and tweak their designs by viewing renderings on their computer screen. "But while the latest computer modeling tools provide a very realistic view of a proposed design, there are many important aspects of the design that are difficult or impossible to evaluate on the screen," said Robert Nankil, Product Designer for AAL. Rendering software is good but it can’t perfectly represent the way that an object appears under actual lighting conditions. We wouldn’t think of investing tend of thousands of dollars to build die cast tooling until we were able to review the actual part. We wouldn’t think of going into production without being able to view a prototype under different light conditions, put a bulb in the product to light it up, and place it into a real-world setting so we can see how it looks. Another reason that prototypes are needed is that many different people in the company play a role in evaluating the design and some are not experienced in the sometimes different art of translating from the screen to the real world. There’s also the issue of evaluating how the casting works with the different accessories and making sure that everything fits together just right."

In the past, AAL technicians produced a prototype of the design from foam using a lathe and hand tools. One problem with this approach is that producing a complicated prototype could easily tie up a skilled person for a week. And since the company has switched to the Techno router, their designs have continued to get more and more complex to the point that it would take considerably longer, perhaps up to a month, to produce some of them. Accuracy has always been a critical concern in producing the prototypes because of thin wall thickness. But it was never possible to achieve the desired level of accuracy with hand-built prototypes. "The details just weren’t there which made it difficult to evaluate the designs to the level that we would have liked," said Andy McMillan, Product Designer. "Another problem was that the accuracy wasn’t good enough to assemble the prototype with the accessories to see how everything fit together and worked as an assembly. Because of these problems, there were some cases where we had to make expensive changes to the mold and other cases where we realized after the product came out that we could have made improvements if we had been able to view a more accurate prototype."

The design group jointly came to the conclusion that a more accurate prototyping tool would help them take their product development efforts to the next level. "We considered several different options," Landefeld said. "Stereo lithography had the accuracy we wanted but the machines that were within our price range did not have the envelope that we needed, which is 18 inches by 18 inches. We looked at some CNC machining centers but the machines that were large enough for our parts were very expensive, over $100,000 in most cases. Next, we looked at a couple of CNC routers, machine tools with the flexibility and accuracy of a machining center but which are designed for cutting softer materials such as wood, plastics and foam. We quickly discovered that these machines had the envelope that we need and that the price was in an area that we could afford. Of the two that we considered, the Techno machine was clearly superior in terms of the accuracy it could provide. We also liked the fact that the Techno came as part of a complete package that included all of the software that we needed to get up and running. Finally, the price was right, under $30,000 for the full package."

The Techno machine is constructed on steel stress-relieved bases with hardened steel linear ways. Its shaft-and-bearing system produces very smooth, play-free motion and is an extremely rigid system that produces high-quality cuts. The machine also uses anti-backlash ball screws. These screws have excellent power transmission due to the rolling ball contact between the nut and screws. This type of contact ensures low friction, low wear, and long life. The ball screws also make it possible to produce wooden parts to the machine resolution of 0.0005 inch. Instead of being ball screw-driven, the less expensive machines use rack and pinion gearing, which has too much play to make accurate cuts in small areas. Also this type of gearing wears out quickly in the dusty environment of a carpentry shop. The other main difference we found between the Techno machine and the others was that the Techno uses a servo motor to control cutting motion while other machines use stepper motors, which can give a stair-step cutting effect. With a smoother cut, sanding and finishing time is kept to an absolute minimum.

With the new machine, AAL designers can now produce prototypes that are as accurate as the finished parts while occupying less than an hour of time on the part of the design staff. The designers export the design from Cobalt in the IGES, STL or DXF neutral file format. They then import the file into the Visual Mill software provided with the Techno Router. With this package, it is a relatively simple process to define the surfaces that will be machined and generate tool paths. Normally, the part is completed in two different setups, one machining the inside and the other the outside of the part. Then the operator sets up the part, starts the machine and is free to go back to their job until it is ready for the second setup. The complicated fixtures produced by the AAL typically take about 8 to 12 hours to machine.

When the part is done, the technician removes it from the machine, performs some minor cleanup, paints it and assembles it with other components that make up the complete product, including a light bulb.

An innovative industrial design firm used out-of-the-box thinking and found a way to produce prototypes at about half the cost of methods used by most firms. Not only was the initial purchase price of a gantry router less than one-fourth that of stereolithography apparatus (SLA) or CNC milling machines, day-to-day operating expenses are significantly less as well. The router's working area is larger than that of conventional milling machines, and it delivers more aesthetically pleasing surfaces than SLA. In another example of the firm's innovative thinking, the router also serves as a coordinate measuring machine. The benefits to the firm's clients are a shorter design cycle, faster turn-arond, the ability to evaluate more design options and lower costs.

Anderson Design is a general-purpose industrial design house with clients in a variety of industries including toys, tools, appliances, heavy machinery, and medical equipment. The company has achieved a consistent record of solving challenging product design problems. Its services range from conceptual design, to focus group research, to engineering, to purchasing and manufacturing support. Many companies choose Anderson Design for its "one-stop shopping" breadth of capabilities. Clients include Becton Dickinson, Black & Decker, Johnson & Johnson, Fisher-Price, Rubbermaid, and Coleman, among others.

Preparing prototype models for client review is a critical part of the product development process at Anderson Design. Until recently, this was done by hand using urethane foam. The company had no way of generating models from its Pro/ENGINEER CAD data unless it went to an outside service. When the decision was made to bring this capability in-house, company officials investigated a variety of options.

Anderson Design first considered SLA, a commonly used method of producing prototype models, but determined that it had several drawbacks. First, it was not suitable for all parts. Aesthetically critical parts with complex surfaces, for example, couldn't be produced with SLA since this technology makes tiny steps or facets in a curved surface. Second, the least expensive SLA system cost about $100,000. Third, that system had only a 12-inch by 12-inch by 10-inch high working area. Many of Anderson Design's projects would require parts made in sections and bonded together. This is a time-intensive and costly option. Finally, because operating expenses are high, SLA models cost nearly twice as much to produce as foam models.

The firm also considered a traditional CNC machine. These machines, made by companies such as Bridgeport, start at $50,000, not including the CNC programming software. To get a model with a large-enough working area, Anderson Design would have had to buy one of the larger machines costing at least twice that.

Then a chance encounter in an industrial directory led the company in a different direction. The ad described a new breed of gantry router that interfaced with CAD systems, had a large cutting area, and a low price. Anderson Design ended up purchasing that machine, the Techno Series III from Techno-Isel, New Hyde Park, New York. The price was less than $19,000 and operated from CNC programming software, Mastercam, from CNC Software, Tolland, Connecticut. Its working area of 24 inches by 36 inches with a Z-axis height of 6 inches was large enough for most of the firm's projects. And it could handle all the materials they needed to cut.

After purchasing the Techno machine and related equipment such as clamps, tools for installing clamps, lighting, vacuum systems, cutting tools, and software, the total cost of bringing automated model production in-house was approximately $40,000. Within three days of installing the Techno system, Anderson Design was billing clients for work done on it. This was largely because the Mastercam software was easy to learn. Although originally designed for metal working, Mastercam is also well-suited for industrial design models because of its ability to generate the most complex contours with little programming effort. Mastercam includes IGES, DXF and CADL converters so that geometry can be uploaded from many CAD systems including Anderson Design's Pro/ENGINEER.

Although the Techno machine was designed for production routing and drilling on a wide variety of materials including wood, plastic, MDF, solid surfacing materials, and nonferrous metals, so far Anderson Design has used it mostly for cutting models out of seven-pound or 15-pound density polyurethane foam, or #35 or #65 Ren Shape. Typically, 4-inch thick sheets of 4-foot by 8-foot foam are used, although a few polycarbonate parts have also been made.

The machine's 0.0020 inch resolution and repeatability and 0.003 inch absolute accuracy ensure that the foam models are faithful representation of the designs created on the computer. This is critical in an industrial design application since the models must give the client an accurate likeness of the eventual end product. The Techno machine's accuracy is the result of several

features inherent to the table, such as the use of ball screws and servo motors. For example, anti-backlash ball screws permit play-free motion that makes it possible to produce accurate circles and inlays. The ballscrews have excellent power transmission due to the rolling ball contact between the nut and screw. This rolling contact also ensures longer life and greater rigidity during the life of the system because of the reduced wear as compared to ACME screws and nuts, which have a sliding friction contact.

The resolution of the Techno machine has allowed Anderson Design to use the system in unanticipated ways. Many of firm's projects involve products that must interface with products already on the market. These products may not be made by Anderson Design's client, which means that the industrial design team doesn't have access to the documentation or CAD files that define them. In these situations, the designers go out and buy the product and then figure out how to design an interface to it. 3D digitizing offers one method of capturing the surfaces of the product for use in the CAD system, but Anderson Design has found most digitizing techniques to be impractical. Laser reflective scanning, for instance, generates too much information for the designer to work with since it captures thousands of x, y, and z coordinates. It is impossible to fit a surface through all these points, so much of the data is eventually discarded.

Anderson Design found a better way to get surface data into its CAD system. They modified the Techno machine to function as a coordinate measuring machine. After securing an object to the machine's table, just as if it were going to be milled or routed, an operator manually moves the machine's crosshead until a flexible touch probe positioned in the tool holder touches the object. The machine's display shows the x, y, and z position of the probe at that point. This value is recorded manually and after the designer has captured a number of points, they are entered into the CAD system.

The benefit of this technique is that a designer has complete control over the number of coordinates that are recorded. Anderson Design has found that between 70 and 80 planned points give a better indication of the surface than the thousands of points that are captured with a laser scanner. Once the 70 or 80 points are indicated in the CAD system, the designer uses them to guide the creation of the existing object's surfaces. This use of the Techno machine once saved Anderson Design six months, the time they would have needed to go through the legal process to get drawings for a particular product. They simply bought the product and captured its coordinates in three days.

In approximately 300 hours of operation, Anderson has had no problems with the Techno machine. This is partly due to the strength and rigidity of the table, which is constructed from extruded aluminum profiles that provide easy clamping capability. The machine also has four ground and hardened steel shafts and eight recirculating bearings in each axis. This shaft and bearing system produces very smooth play-free motion and an extremely rigid system that produces high-quality cuts. Anderson Design has also required no technical support since acquiring the machine. For this company, PC-based CNC has proved to be an affordable, practical, and accurate option for the production of industrial design prototypes, as well as a good coordinate measuring machine from time to time. To the firm's clients this means shorter lead-times, lower costs and, most important, better designs.

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CNC machines are used in a variety of industrial settings and in woodworking shops. Most are out of the price range for the individual user, but can be purchased used for about half the price. These machines increase speed and accuracy when doing large jobs or repetitive tasks.

How CNC Machines Work

CNC machines are used in a variety of industry, manufacturing processes and woodworking shops. CNC routers are used for drilling holes. Some machines have the capability of holding several tools. This allows them to perform more than one operation at a time. They save time and improve accuracy.

CNC stands for Computer Numerated Control. This technology was first seen in the 1970s. The machines need to be programmed and set up properly before operation. Once the initial set up is completed, they are fairly easy to operate and keep running.
In CNC routers, they can be programmed to drill holes in an automatic fashion. This is faster and more accurate over several pieces than in manual drilling. The results are more uniform. This method is very beneficial for larger jobs that require a lot of drilling. Manual drilling can become tiring and when the operator becomes tired, the results can become inconsistent.

Types of CNC Machines

A CNC lathe is a good piece of equipment for cutting wood. These come in models ranging from fifteen to forty horsepower. The amount of power you need depends on the amount of wood you will use with the lathe. The best models operate in several different modes, from completely manual to all CNC. This allows you to tailor the machine’s operation for each project.

A Bridgeport mill is the best in milling technology. Mills are used in many industries, both large and small shops. They are efficient and reliable. Bridgeport mills are built to last a lifetime. However, they are very expensive. The price is out of the range that most people can afford.

The CNC mill is a specialty piece of equipment. It uses computer programming and robotics for accurate operation. The results are more accurate than any person could ever achieve. For this reason, Bridgeport mills are often used in the airline industry. Once the specs are entered, the CNC decides which tools need to be used and automatically changes the tools as needed.
Engraving equipment is made to engrave a variety of materials including glass, stone, metal, wood, composites and many others. The machines mark and engrave with more accuracy than could ever be achieved by hand. Everything from large signs to small lettering can be done, depending on your needs.

Buying Used units

CNC equipment is very expensive and out of the price range of most people. Buying used CNC electronics is an affordable option for some people. You can save nearly 50% or more on some equipment. Be careful when buying used, you want to be sure the equipment is in good condition.
A better option is to look for refurbished equipment. These machines have been inspected at the factory. Any broken or damaged components are replaced. In many cases, the machine is painted and new decals are applied. It’s like getting a new machine for a significantly reduced price. Often, you will get a one year warranty with reconditioned equipment. This gives you time to be sure it is working properly and if not, you can get it fixed for free.