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Rather than spend thousands of dollars on new machinery, consider CNC retrofitting, which can provide accuracy similar to new machinery at a fraction of the cost.

If you are experiencing excessive machine down time with a machine that is mechanically sound, perhaps it’s the control system that is obsolete.

Rather than tossing your old machine and getting a new one — which can be a costly endeavor — consider retrofitting the computer numerical control (CNC). This process entails the replacement of the CNC, servo motors and drives, spindle system and associated wiring.

Retrofit costs are typically between one-third and two-thirds the cost of a new machine, according to an American Machinist Webcast. It also avoids the “hidden costs” of new equipment such as transportation, tooling, training and start-up times.

Steve Colasanti, systems integrator at Dual Electric & Refrigeration Services, agrees, saying in a recent case study at Modern Machine Shop:

The cost of upgrading a machine tool to almost new is typically a fraction of the cost of buying new. If you have a solid machine base to work with, retrofitting machines with digital CNC and servo technology can yield large decreases in cycle time while providing accuracy similar to that of new machinery.

According to the Webcast, along with being less costly than new machinery, other benefits of a CNC retrofit include:

* Typically a 20 percent increase in performance due to the faster CNCs, higher-speed motors and machining technologies;
* Machine electricity usage reduction by as much as 50 percent;
* Increased plant capacity because of smaller CNCs;
* Improved mean-time to repair and mean-time between failures; and
* Better data accessibility and support through upgraded Ethernet communications.

To determine the full value of a retrofit, the Webcast instructs shop owners to perform a standard return on investment (ROI) analysis of the anticipated revenue improvements and the savings from cost reductions in conjunction with all quoted and hidden costs of the project.

While the benefits are appealing, there remain a few key considerations to keep in mind before committing to a retrofitting project. One of these is that benefits will be delivered only by upgrading the servo and spindle system to a high-speed digital interface as well. “It does not matter how fast the CNC can process blocks of part program data if the servo and spindle systems cannot keep up,” according to American Machinist earlier this year.

When you’ve decided to commit to the project, the first step is to investigate the mechanics of the machine and determine the feasibility of a digital upgrade, Modern Machine Shop suggests. “Proper inertial matching calculations for each axis drive system is essential to peak high speed operation,” Colasanti adds. Next, the retrofitting project manager must get an understanding of the electrical system so the retrofitted CNC can be integrated properly.

Once the viability of a retrofit has been established, it’s time to select a retrofitter or retrofit kit provider. A retrofitter selects the CNC and determines the correct-sized drive systems, writes the programmable machine controller (PMC) ladder, mounts and wires electrical components and motors, sets the machine parameters and does basic servo tuning, Bruce Vernyi at American Machinist writes.

Due to their numerous responsibilities directly tied to the success of the retrofit, it is important to be extremely selective when selecting a retrofit partner. The American Machinist Webcast suggests machine shop owners:

* Establish their potential partner’s competency in machine type;
* Ask for documentation of quality;
* Ask for references;
* Get multiple quotes; and
* Make apple-to-apple comparisons.

Some red flags to watch out for when appraising the quotations are a disproportionately low price, smaller servos or spindle systems and a poorly detailed quote.

Once you’ve chosen your partner, make sure to specify the exact CNC model you need and want, plus all the optional contents and additional enhancements you require, the Webcast presenter adds.

http://news.thomasnet.com/IMT/archives/

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VERICUT simulates actual cutting toolpaths in a fully modelled
environment to highlight collisions or clashes, off the machine.

The system already has interfaces for Catia V4, catia V5, Siemens NX, PTC Pro-Mfg, MasterCAM, EdgeCAM and GibbsCAM, while CADCAM companies Delcam (PowerMill), Open Mind (HyperMill) and Missler (Topsolidcam) have all written their own interfaces.
CGTech is now working on interfaces for Surfcam, SolidCAM, Planit AlphaCAM and Camworks, Machinery has learned.

You can see CGTech VERICUT at CADCAM Matters, to be held at Donington Park on 18 November. See www.cadcammatters.co.uk.

http://www.machinery.co.uk/article/20422/More-CAD-interfaces-for-VERICUT-under-development.aspx

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In a subcontrator’s view, its latest mill/turn centre stands out for its powered tooling ability to mill and drill and in particular, through the added flexibility from its two Y-axis cross feeds.

With seven Citizen CNC sliding head automatic lathes already fully occupied and capacity filling fast on the most recent pair of Citizen L32 mill/turn centres installed at HPC (Services) of Ilkeston in Derbyshire, managing director Paul Cobb decided a detailed review had to be made of the type of components and in particular, the amount of milling required in the future.

Only then he maintains, would he make the decision to look for extra machines.

As a very timely result he explains: “We decided to go along to the NC Engineering open house and see first-hand what Citizen could provide.

Our review had already highlighted how milling was becoming more and more important on ‘one-hit’ cycles so high levels of milling and turning flexibility had to be at the top of our agenda.” In Cobb’s view, the new Series 3 version of the M32-V stood out for its powered tooling capability to mill and drill and in particular, through the added flexibility from its two Y-axis cross feeds, one to the turret and second to the gang tool slide.

“So we bought one,” he says “as well as a Citizen L20-VIII.” Cobb describes how his setters cannot believe how the metalcutting efficiency has improved with the new M32.

He says: “We are getting parts from the machine at least 25 per cent and, in some cases almost a third, faster which is proving very beneficial in helping to meet cost-down targets of certain of our customers.” The new M32 machine has not only freed up capacity on the existing Citizen L32s at HPC by enabling more complex work to be transferred resulting in shorter cycle times, there is more.

As he outlines: “With the additional Y-axis we can very quickly electronically adjust tool centre height bringing it exactly on centre line which speeds up our setting.

In-cycle tool change is now much quicker with the new Citizen tool holders you just program a Y-axis move of the turret sideways to the next tool and save an index.” However when it comes to milling - the prime motivator for the purchase, “We can get a lot of very complex milling and drilling performed on a component in the subspindle for free, in terms of cycle time, while still machining away at the main spindle.” The fact that setters no longer have to contend with polar interpolation to produce a flat on a part, for instance, is another bonus.

“We just come in from the side with the tool and mill across the job with the added advantage of using the bottom of the cutter and not the edges.” Maintains Cobb: “We reckon the latest Citizen M32 is the most highly developed machine of its type for producing the class of parts we make up to 32mm diameter.

More and more we are exploiting the machine’s configuration of tooling and axes to machine not only brass and stainless steel components but also aluminium and plastics.” Very effective cutting cycles that could never have been considered before include taking large cuts, up to 10mm deep, by simultaneous twin turning the same diameter from 25mm down to 15mm in stainless steel at 0.12 mm/rev.

Previously, multiple single cuts at 0.03mm/rev would have been taken so the new method has saved over one minute floor to floor time on one component alone.

Then there is the added bonus of reduced idle times from the faster processing of the new control which reduce cycles further.

“When you have a batch of several thousand to run - these are savings really worth making,” he says.

Cobb then adds comments on the latest specification LNS Express 332 barfeed fitted to the sliding head machine.

“Changeover is much quicker and the split block arrangement is far superior to other barfeed designs giving better support to the bar and enabling higher, up to 8,000 revs/min spindle speeds, to be used without any vibration.” HPC employs 50 people and has seen order books swelling month on month from customers in the luxury goods, printing and domestic appliance sectors.

By setting the business to provide a prototyping service, this now accounts for about 10 per cent of the business.

Production and sub-assembly services, as well as a strong design for manufacture consultancy and component development capability, has meant a build-up of a very loyal partnership with a relatively small band of regular customers.

But central to the philosophy of the business is Cobb’s contract machining component superstore theory.

Although it means risk because completed parts are held in the finish parts store for customers to simply call-off when required, it has created three major advantages.

Firstly, customers can enjoy a next day delivery service which pretty well eliminates panic jobs, the scourge of production schedules, but most important, allows Cobb and his team to plan for maximum machine utilisation and efficiency of changeover.

In short, HPC’s machines are producing through three shifts a day over a six days a week with changeovers performed when it is convenient to them! “The spin-off,” maintains Cobb, “is that we are generating profits from sales of over GBP 5 million a year that are ploughed back in the business and we are steadily installing new equipment.” In the first half of 2003, GBP 500,000 was spent, the end of the year a further GBP 550,000 was committed which included both the new Citizens.

For 2004, similar investment plans have been laid and funded in order to maintain ‘The edge’ over competitors in the UK and especially those from overseas that are trying to attract supply contracts against lower pricing.

“If we can maintain a competitive edge through technology and help customers with ‘cost down’ programmes we have found they would rather buy from a known UK source they can work very closely with and one that fully understands the requirements.

It is not all price wars - the benefits of trust in a supplier still holds water providing the supplier does not get complacent and begins to let customers down.”.

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As part of a recent new facilities investment, NC Engineering has purchased an ESAB Suprarex SXE-P1 high-precision cutting system with plasma-arc unit, fume extraction table and Columbus software.

This is providing many benefits in terms of improved product quality, higher productivity and less rework.

NC Engineering was drawn to the advantage of modern plasma-arc that now rivals lasers in terms of quality of cut and surface finish, precision cutting and minimal dross.

It also has the advantage of lower investment costs.

Most plates processed by NC Engineering are 5m long and range in thickness from 2-30mm.

The Suprarex machine was therefore specified with a cutting capability of 32mm and a bed size of 12 x 3m, which enables a plate to be cut on one end of the machine at the same time as profiled components are being unloaded from the other end.

While the vast majority of plates are mild steel, small quantities of galvanised plates are also processed.

To minimise the risk of dust and to comply with all current legislation, NC Engineering specified a filter bed as an alternative to a more costly water table.

As part of the package, ESAB also supplied a copy of its Columbus part processing software, which works well in combination with NC Engineering’s existing 2D/3D CAD software.

The Columbus Data Manager readily imported the 5-6000 standard part files and 5-600 standard nests that NC Engineering has developed over a number of years for its products.

When remnants are being used, the auto-nesting facility within Columbus is useful for maximising material utilisation and minimising waste.

Gordon Moffitt, the assistant works manager, said: ‘The Suprarex has given us a step-change in quality and speed in comparison with the older machine.

‘The software is also significantly better in terms of managing the database of parts and nests.

‘Currently the machine is operating 12-13 hours per day and is proving to be extremely reliable and making a major contribution to our productivity.’.

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ESAB Cutting Systems’s m3 plasma-arc cutting machine can now both cut and mark material with the same plasma torch, offering higher productivity from a simple-to-use system.

Users can now carry out high-speed, low-cost standard plasma cutting, precision cutting and marking, or just thick plate cutting - all with a single PT-36 Plasma torch.

200, 300, 400 and 600A systems are available with the facility to upgrade at any time.

The m3 system consists of the Plasma power supply, PT-36 Plasma torch, m3 flow control and quick-change consumables.

The m3 system has both ‘quality’ and ‘production’ cutting modes and can produce precision cuts on material as thin as 2mm and production standard cuts on material up to 160mm without any sacrifice of quality.

The plasma-arcv system produces a consistently superior cut face with low dross and requires minimal secondary operations.

The m3 plasma-arc system is also highly suited to bevelling operations, as the PT-36 torch design has high standards of concentricity and accuracy, leading to more consistent bevel angles and part size.

The torch is also robust with heavier, thicker nozzles, cups, shields and retainers suited to demanding bevelling applications.

The m3 system is fully integrated with the Vision CNC Controller, simplifying plasma-arc setup and operation.

This also allows fully automatic process switching from cutting to marking mode.

The operator simply selects the material type and thickness and the Vision CNC automatically selects and mixes the optimal start, cut and shield gas combination.

Process parameters for most plasma-arc cutting and marking applications are preloaded in the Vision CNC and custom parameter files can be easily created as needed.

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Hypertherm has announced the availability in Europe of Silverplus electrodes for its Hyperformance systems.

On average, Silverplus doubles electrode life in many applications.

Hypertherm is offering Silverplus in 130, 200, and 260A.

The electrodes are created by fusing a solid silver tip to a copper electrode base and then inserting a hafnium pin into the tip.

The hafnium wear rate is reduced because silver disperses heat better than copper.

A special bond between the hafnium and silver enables more consistent wear rates, deeper pit depths and more robustness to ramp down errors and hard failures.

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EMC Engineering, a North West-based company, has chosen Kerf Developments to supply a high-definition plasma-arc cutting system.

Directors Dave Swift and Kevin Schofield formed E M C Engineering in 2006 with the objective of building a company that could supply welded assemblies at competitive prices.

As a new-start operation they had no option but to put out their component parts to local laser and plasma-arc cutting sub-contractors.

As their customer base and workloads began to grow they found it more difficult to have the parts that they needed delivered when they needed them and at a competitive price.

Having both experienced plasma-arc cutting with previous employers, they considered the possibility of investing in a profiling machine and bringing the work back in house.

Dave Swift said: ‘When looking for a machine we were conscious that there had been significant developments in the plasma market over the past three to four years, particularly on cut quality.

‘We needed a high-speed machine that could produce components that required minimum rework after coming off the machine.

‘As a new-start company we were also having to work to a budget.

‘After considering several alternatives, we selected a high definition plasma-arc cutting system from Kerf Developments.

‘We looked at the sample parts that their machine was able to cut, we looked at their support and service capabilities and last but not least we spoke with several of their existing customers.

‘The feedback that we received about the support that they offer was very complimentary and reassuring for us.

‘The RUR machine that we purchased is fitted with a 200A Kaliburn plasma unit and is configured so that we can cut one plate while other plates are loaded or unloaded on other areas of the machine.

‘The throughput and quality of the parts from 3mm- through to 30mm-thick mild steel have exceeded our expectations.

‘We have also used the machine to cut channels, I beams and box sections, which has been a considerable bonus for us’.

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Odon Equestrian turned to Kerf Developments to supply the plasma-arc cutting equipment that is helping the manufacturer of equestrian equipment improve efficiency and cost.

Kerf has supplied the County Cork-based company with a RUR plasma cutter, which Odon will use in the fabrication of its products, including horse walkers, lunging rings and training equipment.

The RUR profile cutting machine is designed specifically for users with high production demand.

The machine frame is constructed from a mild steel fabricated design, ultrasonically stress relieved and manufactured to highly accurate tolerances.

The cutter itself is driven through twin side rack and pinion drives by servo motors and planetary gearboxes, which are digitally synchronised, while the rail system is manufactured using a precision ground bar mounted on a box section, which is fitted on to thick walled fabricated track stands.

With the RUR range of machines, users are able to configure machine widths and lengths to suit their own requirements.

This allows for larger plate sizes and gives the RUR the capability to load/unload and cut plates simultaneously in order to minimise downtime.

The RUR range is available for conventional and high-definition plasma, and can be configured with combined plasma-arc and oxy-fuel gas heads.

David O’Donoghue, managing director of Odon, said: ‘At Odon, we are renowned for our quality, bespoke and ‘off-the-peg’ equestrian stabling, training and care equipment.

‘The RUR plasma-arc cutter supplied by Kerf has not only helped us maintain and enhance this high quality, but has also increased our production, helping us serve more customers and enhancing the profitability of the company.’.

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