Multi-Axis Control Helps Supplier Stay Out In Front In Ported Cylinder Heads

M2 Race Systems (Farmingdale, New Jersey) is a niche player in a very fast-paced industry. As a supplier to cylinder head designers and manufacturers, primarily in the racing business, this shop produces CNC ported cylinder heads.

M2 Race Systems was founded in 1997 and currently operates full CAD/CAM programming, CNC machining, bench/dyno testing for cylinder head and engine performance, and in-house welding and finishing departments. M2 uses a variety of multi-axis machining centers that have rotary tables for five-axis part articulation.

As president Ron Mielbrecht explains, “Most of our customers are race engine builders, racing teams or the drivers themselves. We do have some OEM contracts, as well as production and aftermarket work, but we’re specialists in a highly specialized industry. This means the responsiveness and technical skill levels of our suppliers must be absolutely first-class.”

M2 Racing Systems operates a full-service shop, producing big and small block cylinder heads, plus custom work for head designers, engine builders and racing teams.

The majority of the work done at M2 involves aluminum and cast iron five-axis machining. A port shape is digitized on a Renishaw Cyclone, and then it is fed through the Windows NT-based shop network system to one of four CNCs. M2’s spotlight machine tool is a five-axis Fadal 4525 with a Sinumerik 840D controller from Siemens (Alpharetta, Georgia) and Nikken rotary tables. The Siemens control features that company’s ShopMill software, which is designed to allow operators to quickly monitor actual cutting conditions through on-screen graphic imaging of the workpiece and tool path.

“All of our porting work requires simultaneous five-axis machining,” Mr. Mielbrecht explains. “This was the reason we selected the more advanced controller on our latest CNC machine. Occasionally, we manufacture billet throttle bodies and, for such jobs, the speed of the machine and the ability to use the rotary as a live fourth axis make part production much better and faster. Integrating these additional functions on the Siemens controller was simple.

“Typically at M2, all our part programs are in the 15 to 25 megabyte range, so we drip feed everything” he continues. The PC architecture on the machine controls makes integration with the other equipment in this shop much easier as well. The control allows us to run the program directly from the hard drive. The machine is connected directly to the shop network, so accessing a program becomes a routine cut-and-paste operation.”

“Furthermore,” he explains, “the Siemens 840D allows us to tune in the machining parameters, thus creating better machining transitions and quicker run times. It processes information at lightning-fast speed, much better than others we’ve investigated. Though very powerful, it can be run by our operators with only a modest amount of training.”

On the machining center, the control manipulates all aspects of operation, including spindle orientation, five-axis movement, tool changes, table motion and so forth. The data are stored in both the memory of the control and the hard drive of the PC. M2 typically uses one main operating program and calls up several external programs (not sub-routines) that would be much too large to fit into conventional memory.

M2 often runs single parts requiring up to 8 hours of unattended machining.

CNC ported cylinder heads are produced on multi-axis machining centers using the Siemens Sinumerik 840D controller.

Therefore, setup is critical. A part can finish at the end of a day shift, with minimal changeover, another part can be machined overnight. This scenario occurs almost daily, according to the company. Once again, the machine tool control becomes vital to this procedure. As Mr. Mielbrecht reports, “The ability of the control to store so much data locally makes it easy to change the fixture plate and load the next program in 15 minutes or less. The machine carousel holds sufficient tools to do each job, so we don’t need to be concerned. Our older CNC machines could hold only about six tools typically, because the movement of the fixture would contact them in the carousel.”

M2 places particular emphasis on the need for five-axis simultaneous machining, because this method of cutting ports enables all the machining lines to follow the contours of the port shape. This philosophy is also critical to the optimization of airflow for increased horsepower and torque, which is the basis for any head porter’s reputation.

This shop currently supplies CNC ported heads for big and small block Chevrolet, Ford, Chrysler and various import engines. In addition, M2 scan-and-machine services work from port designs at concept stages for custom racing and other applications.

In commenting on the service received from his control supplier, Mr. Mielbrecht observed, “They [Siemens representatives] have been very helpful in getting the machine [Fadal 4525] up and running for us. Any assistance needed has been provided for only the cost of the service contract. It’s great to know they have the desire to help us get the most out of the machine.” He also notes that the control’s Windows-based software is easy to use and helps keep M2’s CNC up-to-speed.

http://www.mmsonline.com/articles/1203bp2.html

Faster Milling Of EDM Electrodes With Retrofit CNC Package

Dana Heckendorf of D. Heck Tool LLC (Thompson, Connecticut), a precision moldmaker working out of his garage, wanted to compete with bigger shops that had Computer Numerical Control (CNC) equipment. This led him to consider retrofitting his manual Kent milling machine with a CNC retrofit package. With a Mitutoyo MillStar CNC from Mitutoyo Corp. (Aurora, Illinois), the shop owner can program the shape of a complex EDM electrode in 45 minutes and mill the part in 30 minutes. According to Mr. Heckendorf, the single electrode does the work of a dozen simpler ones that would take most of a day to mill or grind manually.

"Basically, we've boosted electrode throughput more than seven to one and streamlined our EDM die sinking as well," Mr. Heckendorf says. With two-axis CNC, the moldmaker quickly mills the more intricate electrodes he needs to cut mold cavities faster and with a better finish than before. Faster electrode milling and subsequent cavity cutting trimmed delivery time on what was a six-week job by seven days. "With the MillStar, I'm doing very high quality EDM electrodes in far less time," says Mr. Heckendorf.

D. Heck Tool specializes in prototype and small production molds for plastic parts. Much of the tooling produces tiny medical and switch components. The stainless and tool steel mold frames are generally about 8 inches square by 10 inches high. While mold cavities are usually cut by a Hansvedt 201 CNC EDM, the graphite electrodes used to cut the pockets must be milled.

The smallest electrodes used by D. Heck Tool are just 0.010 inch wide. "I could mill them manually," says Mr. Heckendorf, "but electrodes are very time consuming parts to make manually."

When Mr. Heckendorf started his business three years ago, he thought CNC conversion was the smart way to go. "It's hard to sell mold-making services without talking CNC," he says. "The first question they ask you is, `what do you have for CNC equipment?'"

Sophisticated computer control was a new endeavor for the small shop owner. As a lead moldmaker, Mr. Heckendorf had long made molds with a manual finish grinder and knew nothing about CNC programming. However, the milling machine he'd bought had a bolt-on power feed and Mitutoyo digital readout, so he spoke to his MTI representative about a new CNC retrofit package.

About a year ago, he upgraded his milling machine with the Mitutoyo MillStar control package. The expandable two-axis control promised the right capability, given the type of work to be done and the background of the user. "I knew I wanted a two-axis CNC because I had no hands-on experience programming," says Mr. Heckendorf.

Mr. Heckendorf visited surrounding job shops and tried several CNC packages. "The Mitutoyo package was one of the very few to run through Windows 95, which is an easy operating system to learn," he says. "It's also got good graphics and can be programmed in G-code or plain shop language."

In addition, canned cycles automate routine operations such as hole patterns, lines and arcs. More complex jobs are set up through drop-down menus on the 10-inch color screen. Function keys let the user override the automatic control and change feed rates and other parameters on the fly. Mr. Heckendorf was able to use the control after only four hours of instruction.

Precision EDM electrodes for cutting molds are milled to the shape of the finished plastic part. Customers typically supply Mr. Heckendorf with hard copy drawings of their molded parts. Mr. Heckendorf extrapolates electrode dimensions from the drawings allowing for plastic shrinkage, overburn, and other factors.

Most electrode jobs at D. Heck Tools are programmed in conversational mode. Programs stored in the MillStar memory or on disk also give D. Heck Tool repeatability difficult to achieve with manual operation.

The EDM uses the precision electrodes to cut mold contours within 0.0002 inch. Using more complicated electrodes closer to the shape of the finished part burns away more of the mold cavity faster and leaves better quality finishes.

One complex mold for a speedometer/tachometer case previously required 28 different electrodes that were set up and machined manually. By comparison, a similar gage case mold required just 12 electrodes milled under CNC. As a result, the typical six-week job was shortened by seven working days. For D. Heck Tool, the switch to CNC is paying off in shorter mold delivery times and lower costs.

Time saved in setup also means more effective use of the milling machine. Mr. Heckendorf estimates his milling machine actually ran just four days a month in the days of manual setups. Setup occupied the rest of the time. With CNC operation and stored programs, the same machine now makes chips three weeks a month, a great increase.

For a one-man shop in a competitive market, a CNC retrofit package has proven itself a powerful business advantage. "The control allows me to quote five weeks on a job someone else is quoting nine weeks on. That's what my business is built on," he says.


http://www.mmsonline.com/articles/0599bp1.html

Communicating With The Machine Tool

If you continue to operate a bankrupt company in the same manner, you will continue to be bankrupt." This was the primary thought of Steve Brown before he acquired a failed stretch forming company in Gardena, California. Mr. Brown was President of Camarillo Dynamics, an aerospace machining company.

Mr. Brown merged the two companies into the single Advanced Machine & Stretch forming International, Inc. (AMSI). After making some improvements to the company, he then launched a modernization and equipment refurbishment program designed to improve its standing in machining and stretch forming.

At the center of the equipment list were six Cincinnati Skin Mills with bed lengths of 30 to 70 feet. They were six to 12 years old and had the original Acramatic controllers.

Graham Aerospace, Inc. (Cowansville, Quebec), which had a track record of rebuilding skin mills and fitting them with state-of-the-art controllers, was selected for the AMSI project. A key ingredient of this selection was the company's position as a certified system integrator for the Vickers A2100 machine controller. Graham had recognized that at the heart of the Vickers A2100 controller were dual Intel Pentium powered PCs with the Microsoft NT Operating System. This system allowed Graham to provide customized solutions to specific problems and specific solutions to generalized problems. The A2100 provided a commercial platform that met recognized industry-wide standards and allowed the company to offer value-added implementation of a machine/controller combination.

The system uses the Microsoft networking features for file sharing and for implementing a common work environment to allow schedulers, Q.A. personnel and management to exchange critical production flow information. The system also has Network File System (NFS) that allows it to communicate directly with the Unix-based CAD/CAM system. The CNC programs can be stored off the machine tool and assigned for execution, eliminating current DNC requirements. This feature also permits remote log-in from the A2100 and access to the CAD/CAM software on the Unix-based workstation. Program changes can be accomplished directly from the shop floor. Video images can be viewed at the A2100 monitor.

The AMSI skin mills are equipped with Renishaw probes and the output is delivered to the Unix workstation for evaluation, decision making, and S.P.C. (Statistical Process Control). The output is automatically placed in the Q.A. system for evaluation and action. True vector probing is then integrated into the machine tool controller allowing it to probe any surface while eliminating the CMM machine process requirement. This has the effect of checking the part directly to the original database stored on the Unix workstation. Other probes can be installed on the machine, and intelligent decisions can automatically be made based on their feedback.

One of the first steps that AMSI took was to implement a CAD/CAM system capable of taking advantage of its new machine and control technology. NCL is a powerful Computer-Aided Manufacturing software package that generates simultaneous two-through five-axis NC tool paths and provides parametric 3D modeling. All geometric modeling and tool path functions are fully associative. A change to the model results in an immediate change to corresponding tool paths.

NCL also supports full parametric programming where a family of parts can be machined by simply filling in a form. The parametric ability of NCL combined with the probing and communication capability of the A2100 allows variables to pass from the control to the CAD/CAM system. Tool diameter and length data can be modified at the control and sent to NCL where the tool path is automatically recalculated and sent back to the control. The same procedure can be used to change fixture setups and even make changes to the part geometry.

NCL/IPV (In-Process Verification) simulates the metal removal process right on the computer screen. It allows verification during the programming cycle instead of at the completion of a program as is usually done traditionally. With the NT communications capability of the A2100, a programmer can make a change, verify it using NCL/IPV and run the new version, all without leaving the machine tool. The operator can also play back the IPV file to become familiar with a new program.

NCCS (Newport Beach, California) has developed a special version of its universal postprocessor, PostWorks, which resides on the A2100 control. Through a joint marketing agreement with NCCS, Graham Aerospace is able to provide PostWorks on all A2100s that it sells. This allows the A2100 to accept generic binary or ASCII CL files from virtually any CAD/CAM system. "Using this technology, our NC programmers no longer have to concern themselves with postprocessing at the CAD/CAM system," says Terri Brown, chairman of the board of AMSI.

Both revenue and profit have significantly increased at AMSI. It is expected that these increases will be even more dramatic as the changes are fully implemented and mature.



http://www.mmsonline.com/articles/0399bp4.html

What is a CNC Machine

What is a CNC Machine? CNC stands for Computer Numeric Control. Sounds complicated, but it isn’t. Years ago, it was just NC, or Numeric Control. Since, they’ve added computers to control the machine.

In the simplest of terms, think of a drill press. It’s a machine that drills holes. But before you can drill the hole, you have to loosen the chuck, install the correct drill bit, drill the hole in the correct place, turn off the drill, and remove the drill bit. Manually, this could be time consuming and cause fatigue over the course of numerous parts. This is a simple example, but throw in some lathe or milling machining and you have a greater chance for error.

With the CNC machine, all of this drilling can be done automatically instead of the manual process listed above. Machining has to be precise, and whether you use a CNC lathe or milling machine, you have to make sure the part is right. The computer takes a lot of the guesswork out of the machining of these parts. In fact, a CNC programmer can sometimes get bored watching the machine do all the work.

But there is more programming for the machine than you would think. The operator has to enter a set of instructions. The programming uses about 50 words and tells the machine how fast, how deep, and location for machining.

What can you do with a CNC machine? In manufacturing, you can use this tool for milling, drilling, reaming, boring and counter boring. You can also groove and thread parts in a CNC turning center. You may have several setups including CNC lathes, CNC drill and tap area, CNC milling, or even CNC grinding.

EDM (electrical discharge machining) can also take advantage of CNC operations. EDM can be either vertical or wire. A vertical EDM machine uses an electrode to make a cavity for a plastic injection-molding machine. A wire EDM machine uses a wire to cut metal for a tooling operation for fabrication. EDM is more closely related to making tooling for other machines, people often overlook the use of CNC with these machines.

CNC machines can also be used with routers in the wood industry. CNC can also be used with lettering and engraving.

I hope this gave you some basic information about what a CNC machine is and what they are used for.


http://cnc-info.blogspot.com

Probes improve CNC machining cycle times

Dunlop Aerospace Braking Systems, a part of Meggitt, is a global organisation that designs, develops and manufactures wheels and brakes for commercial and military aircraft applications. Aircraft production in the UK has experienced steady growth and to meet this demand the hub and flange cell at Dunlop Aerospace purchased three key CNC machines between 1998 and 2000, at that time actively specifying Renishaw probe systems. This has increased process consistency and has also had a marked effect on the manufacturing time.

* Dramatic reductions - Andrew Cartledge, team leader of the hub and flange cell, speaks positively about the decision to employ Renishaw probing systems, 'We've seen improvement both in machining cycle times and the overall set times every time we've introduced a component to the cell'.

'This is critical to our New Product Introduction process (NPI) which we use every time a new wheel is introduced, essentially allowing us to 'design for manufacture'.' * Runners, repeaters and one-offs - orders for wheels fall into three different categories according to the number of batches made each year.

The 'runner' orders are classed as those wheels produced in more than 10 batches a year; 'repeaters' are less than 10 batches a year.

Dunlop Aerospace also supply one-off orders and recently succeeded in a very impressive project to re-manufacture components for the 1950s Canberra.

This involved taking original drawings and re-programming the machining through the modern CNC process.

Cartledge continued, 'NPI involves a process we call Manufacturing Process Approval (MPA) whereby any machining process must be closely analysed to see if it affects the stresses and component strengths of a wheel assembly.

All the main 'runners' and any 'repeaters' that are introduced to the new cell need MPA before production can start.' * Investment in technology and automation - between 1998 and 2000 Dunlop Aerospace chose to spend nearly GBP 2 million on three state of the art multi-axis CNC machines; a multi-axis Mazak Integrex - a turning centre with full C-axis and driven tooling to give milling capability; a Mazak HV800 5-axis horizontal machine centre; and the most recent investment, a Mori-Seiki MT4000, at the time the first of its type in the UK.

* Probe systems make all the difference - the underlying technique made possible by the integration of the probe systems is the ability to identify the component position and material condition, updating and monitoring the deviation in the wheel forgings.

This reduces cutting time, as it eliminates fresh-air cuts - this is because the probe ensures that the critical surfaces of forgings are accurately located and metal cutting starts immediately.

* The importance of one hit machining - during the cutting process stresses are relieved in the material, so one hit machining results in the cutting process achieving greater consistency.

L77 aluminium is the most commonly used material and, with the high cost of each process, it is essential that Dunlop Aerospace keep scrap levels low.

In-process monitoring and tool offset updating ensures process control and minimises scrap.The nature of the aviation industry demands ever-increasing accuracy and quality, ensuring both wheels and brakes can be reliable in all conditions and scenarios.

http://www.manufacturingtalk.com/news/rea/rea422.html

Trade old machine tools for latest CNC models

Trade old machine tools for latest CNC models Trade-in values for used machine tools against new purchases should be available within around 10 min from C Dugard, UK, under its Express Delivery from stock package for CNC machine tools. Trade-in values for used machine tools against new purchases should be available within around 10 min from C Dugard of Hove under its Express Delivery from stock package for Hyundai-Kia and its own Dugard Eagle range of mill/turn centres, lathes, vertical and horizontal machining centres. In addition, due to its expertise in the machine tool market, certain other machines from the extensive turning, milling and grinding products available from C Dugard can be included for fast track pricing.

This capability draws on C Dugard's specialist second-hand machine tool sales operation and worldwide network of distributors that provides a ready market for any traded-in equipment.

Says managing director Eric Dugard: 'Our aim is to provide a 'one stop' solution to customers with the availability of two trucks and crews.

We can quote a sale, price a trade-in, arrange delivery and very often the trade-in price can provide the deposit and part finance for the new installation.

We get a lot of market feedback from our connections around the world and do not have to involve third party machine tool sales companies.

Therefore we can often provide a more competitive and immediate package deal.' Around a third of Dugard Eagle machines are now sold this way and as Eric Dugard points out, the international contacts can prove to be very valuable to customers.

He cites one customer with four Manurin lathes that the UK trade were very reluctant to accept.

'Our distributor in France was able to quickly source an outlet for the French built machines enabling us to painlessly extract the machines and install the new lathes in the customer works within a few days of the order being confirmed.'

http://www.manufacturingtalk.com/news/cdu/cdu160.html

VISI-Series - machining STRATEGIST

Shop Floor Machining Solution machining STRATEGIST is a CAM system designed for high speed machining with built-in logic for use with solid carbide and carbide insert cutters. Developed by the people at Vero International in England, machining STRATEGIST is used in Mold, Tool and Die, Prototype and Pattern shops for generating cutter paths on complex geometry developed in disparate CAD systems such as VISI-Modeling, CATIA, Unigraphics, Pro/Engineer, SolidWorks, and Solid EDGE.



Most popular CAM systems that are used in today's mold shops weren't designed with High Speed Machining in mind. In order to take advantage of today's cutter and machine tool technology, machining STRATEGIST had to be and was designed completely from scratch. Released less than 6 years ago, it is the newest technology on the market today.

Using the latest software development tools, Vero people created a CAM system that generates efficient toolpaths very quickly, while still maintaining unparalleled ease of use. Strategist also takes advantage of multiple processors for more productive programming. But, the biggest advantage of machining STRATEGIST is in it's toolpath generation. Because it maintains a cut stock boundary, it knows exactly where to go to remove stock. It allows use of higher feedrates because toolpaths are created without any sharp corners so cutter deflection is maintained more constant. And all this allows your CNC machines to run faster and more productively with less wear and tear.

Advanced Rest Machining
Steep and shallow areas are machined in a single toolpath with different strategies - steep and shallow machining - for each. Crucially, rest machining can be calculated in areas where the final cutter is smaller than the curvature of the part.

Point ReductionAll machining passes operations now support enhanced point reduction and arc fitting. Arc fitting is enabled by default for those operations where it is likely to have the biggest benefit. In benchmarking, reductions of over 50% in NC file size have been observed.

Horizontal Finish Machining
Horizontal surface machining has been designed to use a flat-based cutter. This strategy will dramatically reduce the time it takes to finish machine the flat areas on a complex 3D mould, and in finish machining pockets in aerospace components.

Rest Roughing
The system will calculate the rest areas of a selected toolpath - areas left on the surface that have been insufficiently machined - generate a stockmodel with this information, and edit passes to it.

This is a good way to generate efficient toolpaths, reducing air-cutting and shortening the machining time.

Morph Machining
Each pass in a morphed "patch" - the toolpath prior to linking - echoes the shape of the one before, while suggesting the shape of the one after. Akin to machining with the flow of a surface but by creating a set of boundaries with control points, the operator can exercise tight control on how a toolpath flows as it is mapped onto the model.

It is now possible to access two advanced machining presets quickly and easily from the menu, consolidating pencil milling and constant surface stepover.

Parallel Pencil Milling PassesA set number of passes are offset from an active boundary or existing single line toolpath.

Tapered cutter support extends to carbide insert button cutters, predominantly used for roughing. To leave a tapered finish, it is critical to rough with taper to leave a material-on condition.



http://cnc-info.blogspot.com/

CNC machinery

Glass CNC, or computer numerical control technology, was first used to modify ordinary glass-engraving machines to render them capable of completely automated engraving. A new sector of glass machine production was thus created.

Since then, CNC machinery has developed to the point where they can perform a complete range of glass processing operations from basic operations like cutting, bevelling, edging, drilling, etc. to controlling the entire glass processing line. CNC technology reduces production costs, minimises waste, increases productivity, improves glass quality and safety. The skilled worker with long years of glass processing experience will be less necessary, as CNC technology guarantees increased glass quality and faster processing speeds. Only fifteen years ago the glass industry was unaware of CNC machines. Nowadays this technology sets new glass standards that could not be otherwise achieved. In the future, CNC machine producers are focusing on meeting market demands by offering machines that are easier to maintain and use. Various CNC machine producers can be found through the selected links.


http://www.glassonweb.com/articles/article/98/

Fagor automation offers CNC systems - Machine tools of Spain: European quality

Conversational 8055i TC/MC CNC's from FAGOR AUTOMATION

The most outstanding feature of FAGOR AUTOMATION's CNC systems is their operating friendliness, simple and intuitive, which gives them a competitive edge widely acknowledged by our customers. There are standard models with ISO and high level programming with the possibility of conversational programming that make them adaptable to both single-part work and long runs.

Conversational CNC's from FAGOR AUTOMATION (8055iTC/MC) may be adapted to the usual work method of a shop and have been designed to make intuitive programming easier for the operator; they have an interactive editor based on operations associated with each one of the processes that make up the machining of a part. The previous graphic simulation helps verify each operation and correct the data entered.

The system is programmed very easily. All the automatic operations have an interactive help, geometry defining area and other areas to set the machining conditions of the roughing and finishing stages with several editing levels or types of cycles with their own screen. This minimizes the preparation time; and any operator, without previous programming knowledge, can operate the CNC and carry out typical operations efficiently.

Its intelligent profile editor, similar to an integrated mini CAD, helps create profiles without the need for complex calculations by directly entering the values and parameters of the part, run a previous simulation and machine the part defined. If the part is too complicated, the preparation may be faster than when using an external CAD-CAM.

Telediagnosis and Setup Assistance On FAGOR AUTOMATION CNC's

FAGOR AUTOMATION has developed the Telediagnosis option to remotely control all the incidences that may occur on the machine.

Just connect the CNC with the PC of the Technical Department via the internet through a modem. This way, the technician, from his work table and at his own PC can remotely manipulate and observe the system status (CNC-drives-motors). This functionality may be used to detect PLC program errors, do a setup, or change parameters (CNC, motors mad drives), saving in travel expenses and labor of the technicians and minimizing machine down time by receiving assistance and error diagnosis immediately.

In order to facilitate the setup, it offers assistance such as the oscilloscope function and the circular geometry test.

The Oscilloscope function shows the response of the axes in time. With this feature, the signals may be seen directly at the CNC. (variables of regulation, path, feedback, etc.) without requiring external devices to check the status and facilitate the adjustments of the machine. The advantage of this feature is that the setup and the troubleshooting of incidences are faster and the diagnosis easier (even remotely) because the signals generated by the oscilloscope may be sent by fax or email.

The Circular Geometry Test may be used to cheek the behavior of the axes when doing a circle by enlarging the measuring errors of the axes. This function helps detect mechanical misadjustments and check the performance of the electronic equipment quickly while saving on additional devices.


http://cnc-info.blogspot.com/2007/01/fagor-automation-offers-cnc-systems.html

Wire EDM Machines: An Overview

While there are many brands and models of Wire EDM machines available today, the three most prominent manufacturers are Elox, Japax, and Mitsubishi.While each of these companies manufacture similar products, there will always be some varying features such as the User-interface with the CNC controller, the numbers of wires, be it a 4-axis or 5-axis Wire EDM machine, type of electrical current (AC vs. DC), and the gauges of wires that can be used.

Another very big difference will be the size of the tank in which the manufacturing is accomplished.Some examples of specifications for one model from each of these companies are:Elox Fanuc Model M - (the Fanuc indicating the type of CNC controller that is a component of the Elox Wire EDM) has an X-axis path of 20”, a Y-axis path of 14”, and a Z-axis path of 10”Japax Wire EDM Model LDM-S - has a Y-axis path 13.8” and capable of machining a work piece with the measurements of 15.7” x 19.7” x 5.9” and a table that moves 7.9” x 13.8”Mitsubishi Wire EDM Model DWC 110 H-1 - has an X-axis of 12”, a Y-axis of 18”, and a Z-axis of 10”Each of these models only represents one of many different models offered by their respective manufacturer.

Variations will be observed from model to model with some differences including the distance that each axis wire can travel, the size of product that can be manufactured and the CNC controller.When selecting a wire EDM machine, one must take into consideration the product that will be manufactured, the degrees of tolerance and variances that are allowed, how detailed the cut will be, and not least importantly, the funds available for purchasing the wire EDM.While Elox, Japax and Mitsubishi are three prominent manufacturers of wire EDM machines, remember that there are also other manufactures of wire EDM machines.


http://cnc-info.blogspot.com/search?updated-max=2007-01-23T01%3A31%3A00-08%3A00

Robotic sorter removes parts from CNC profilers

'Dynamic Robotic Parts Sorting’ automates the removing cut shapes from the skeleton produced on a CNC 2D shape cutting machine so giving unattended material handling for ‘lights-out’ work.

Automated Concepts (ACI) introduces Dynamic Robotic Parts Sorting - DRPS - which automates the tedious task of removing cut shapes from the skeleton produced on a 2D shape cutting machine. DRPS also converts nesting data to robotic paths automatically. Many manufacturers using CNC shape cutting machines automate the sheet handling for loading and unloading the cutting machine.

However, the removal of the shapes from the skeleton in most cases is done manually.

But with ACI’s patent-pending DRPS manufacturers will have a completely automated shape cutting operation that does the following.

* Provides unattended material handling for ‘lights-out’ operation.

* Improves production throughput.

* Offers a seamless process from sheet, nesting and shape cutting to part removal.

* Reduces operating costs.

* Maintains job order integrity.

* Assures an organized and repeatable process.

The DRPS system from Automated Concepts is capable of unloading cut parts by job or offloading cut parts to pallets, shelves or conveyors.

And DRPS easily integrates with manufacturers’ existing CNC cutting operations.

Features of the DRPS system include a multi-axis FANUC robot and controller, application specific grippers, configurable safety systems, stack height collision detection, job order tracking and reporting, and optimized part placement.

http://www.cncmachinesinfo.com/articles/

4×8 Machine design comparison

The Machine Tool Camp 4′x8′ is a light-weight machine. The instructions are detailed but more of a connect-the-dots type deal rather than a tutorial. Metric or imperial is irrelevant here because you would probably order most of your parts from this company.Pros:1. Easy to assemble once you have all the parts (Order from them. Its cheaper and easier.)2. Light-weight so could be moved around, within reason.Cons:1. Light-weight causes vibration during use.2. Light-weight material may deflect (bend or bow) slightly during use.3. Less precision.4. Might be hard to cut aluminum frame members to the tolerances listed.5. I would have liked more of a tutorial in the instructions rather than just connect-the-dots. Instructions need more large pictures.
Cad Cut CNC 4′x8′ Router is a heavy duty machine. It is as close to an industrial machine as you will ever get. The instructions are pretty good with lots of big drawings as well as tutorial. This is a big heavy machine. If you are looking for precision then this is it. I think this one would be easier to do in metric than the other, if you feel you must.Pros:1. Very high precision machine.2. Heavy weight means no vibration during use.3. This machine is stout! No deflection here. No bending of frame or gantry during use.Cons:1. Big heavy machine.2. You must weld frame. (Any cheap stick-welder will do. Mine costs less than $100. It looks pretty easy to do.)3. Takes two people to man-handle some of the pieces during assembly.
And now a few words about the big routers in general.1. You should go to the garage with two yardsticks (meter-sticks?) taped together and see if you really have 6′x11′ clearance somewhere. These machines are really large! You are talking about a permanent fixture that can’t be easily moved. These things are as big as a car!2. Small motors are better. They can still be powerful but the smaller and more lightweight the better. You don’t want to weigh the gantry down with big heavy motors like I have. It’s a headache.3. You should consider if you really have the money for one of the large machines. It adds up. Expect to spend $5000+ US before all is said and done.4. I don’t plan on using Gecko’s for the controllers. I am going to use Rutex because they look like they have more bells and whistles and there is less wiring to be done. In my case, the schematic parts of all the “Plans” are useless. You should consider if you will follow the schematics or not.


http://cnc-info.blogspot.com/

Efficient CNC flexible system transfer saves time and money

Michigan) has been proving to the industry that a U.S. manufacturer can be competitive on cost and quality. The company attributes its success to its investment in manufacturing technology and training.

To meet quality and volume requirements from a customer who hoped to increase the torque and load-bearing capabilities of its full-size pickup trucks and SUVs, AAM engineers developed a process to produce a new rear differential gear carrier. It was the largest the company had ever produced, at 118 pounds.
The process initially used a series of large horizontal machining centers (HMCs) to meet the demand for the 11.5-inch carrier. Then, using the same process, fixtures and tooling, AAM ramped up using aCNC Flexible System Transfer (FST) line from Heller Machine Tools (Troy, Michigan) when volumes went from 35,000 to 240,000 parts annually. The process and the equipment permitted the plant to respond quickly and cost-effectively to the change in demand while consistently achieving quality goals.
In developing the carrier design, AAM paid special attention to details that would positively affect the part's perceived noise, vibration or harshness characteristics, and would thereby provide an advantage to customers in the pickup truck and SUV market.

Once the parts were designed, the company conducted simultaneous engineering programs with three machine tool companies to evaluate each vendor's approach to its manufacturing challenge. In each case, AAM was interested in flexible manufacturing cells to handle relatively low initial production volumes. The company also looked for machine tool vendors that used Hirth couplings on their rotary tables, which AAM felt would help it meet critical tolerances. The purpose was to prove that the critical dimensions could be consistent on a machining center.
Carrier housings and differential case housings are two important axle components, which AAM machines and supplies to its customers. These parts have been produced by a number of different machining processes: for example, carrier housings were machined on single-spindle horizontal machining centers and dedicated transfer lines, as well asCNC lilt-and-carry transfer lines. The differential case housing was produced on single-spindle HMCs and lathes.

Rather than using 11 to 12 HMCs to produce the housings, AAM invested in a single Heller EST. In the experience of its Three Rivers facility, the FST has proven to be a reliable high production system and to be more cost-effective than HMCs. According to AAM, the FST has the benefits of using less floor space (in this case, about 30 percent less) and has capital costs of up to 25 percent less than conventional transfer lines.

The facility uses the 14-station FST to machine the 11.5-inch carrier housings. These operations include face milling, drilling pan holes, and machining pads for end-cap seating and rough-boring the axle tube bores. The FST then completes the boring process, maintaining the perpendicularity of bores in the carrier. Each bore is completed in three passes. Once the part is finished, it is unloaded and put on a conveyor to a robot-loaded machining center cell, where the remaining holes are drilled and tapped in the carriers. Empty fixtures in the FST are returned via an overhead conveyor to a washer and then back to the load station.



http://cnc-info.blogspot.com/search?updated-min=2006-01-01T00%3A00%3A00-08%3A00&updated-max=2007-01-01T00%3A00%3A00-08%3A00&max-results=50

Build your own CNC machine

Ready for some hard core gadget creation? If you thought your dremel tool was handy before, in today's How-To we'll start building our own CNC machine. Aside from the geek factor, it can be handy for making things like PC boards without chemicals or maybe some little styrofoam voodoo heads of all your enemies, uh friends.

Gentlemen, start your soldering irons.

Computer controlled mills have been around for a long time. If you just want to buy oneone,

Sherline makes mills that are ready to go (pictured is their CNC ready model -- just add your own motors and controller). But then again, if you wanted to buy one, you probably wouldn't be reading this, now would you? A CNC machine is a lot like a precision drill press with a table that moves in two directions -- seeing a commercial unit like the one above should help you visualize the end goal. We'll be making ours from scrounged, recycled, and adapted parts; today we'll be going over the basic parts we'll need to build our own.



Parts Hunting
For Part 1 of the How-To, we'll go over all the major components of the project and get started with the controller.
The major components of the DIY CNC machine:

• Stepper motors
• drive positioning screw
• 3 Axis stepper motor controller
• Linear slides

The most important component to determine the construction of your milling machine is the motor. Motors can be purchased from surplus houses, but the cheapest place to get them is from old dot matrix printers. Apple Imagewriters are one of our favorite sources. They contain multiple stepper motors, and the primary is pretty beefy. As a bonus, just about every dot matrix printer has a hardened steel rod that can be useful for our nefarious goals.

A stepper motor is an odd beast. Most motors spin when power is applied, stepper motors contain multiple coils. If the coils are energized in the proper order, the motor will rotate a small amount (a step). We'll take full advantage of the nature of stepper motors with this project. To simplify your life later on, you'll want to find stepper motors with more than four wires. Four wire motors are usually Bipolar motors. They produce more torque, but end up complicating the control circuit. The preferred type of motor for the frugal hobbiest is Unipolar. These usually have five or six wires, and they're pretty easy to work with.

Most stepper motors are labeled. The major points of interest include the voltage, resistance and the number of degrees per step. Knowing the number of degrees per step is vital for configuring the software to properly control the machine later on. For a three axis machine, at the very least you'll want the X and Y axis to both have identical motors. It's not the end of the world if they don't match, but it's more of a pain later on.

The drive screw is the next piece of our project. Commercial units use linear ball screws or linear gears. The commercial parts aren't cheap, but you can get away with some 1/4-inch threaded rod from the hardware store. Instead of anti-backlash nuts, we'll use these handy 1-inch long 1/4-inch nuts. Just about every hardware store has them, and they produce very little play. Try out the hardware at the store because defects in the nut or rod will produce drag that's easily noticeable by spinning the nut on the rod.

To couple the rod to the motor shaft, we'll use vinyl tubing with a pair of collars. The tubing is 1/4-inch inner diameter and prevents binding by allowing some play between the rod and the motor. You can get suitable collars from a model airplane store (The hardware store had some, but they were overpriced). Alternatively, you can make your own like we did from nylon bushings and hex screws.

Finally, we'll need some linear slides. One easy out is to purchase a used or surplus XY table that's built just for this purpose. Custom designs can be built using ball bearings. Above is the linear rail that
ShopBot uses. They machine the edge of a piece of steel and use this cool angled roller bearing.

We built this linear slide from a 1/2-inch steel rod and multiple bearing surfaces. It works, but we don't recommend building it if you value your sanity.

Once uou've bought or salvaged a set of motors, you'll need a controller. The controller provides the interface to the computer, drives the motors and can provide some simple feedback to the computer. The stepper controller has to be powerful enough to drive the motors you've selected. We sifted through lots of stepper controller designs looking for one that presented the best value.

In the end we found this design for a relatively simple parallel port interface that originally appeared in a 1994 issue of Nuts and Volts. Today, the expensive UCN5804B is only available as a surplus item, but now the entire controller can be built for about $22-$30 in parts. (If you use a heavier motor like the ones from the Imagewriter, you might need to add some separate power transistors.)

The parts list at the link is a bit outdated, here's our updated shopping list.

• 3 - UCN5804B -alltronics.com
• 12 - 1N49355 Diodes - Part 625-1N4935 from Mouser.com
• 2 - .01uF Capacitors - Part 581-SR155C103KAT from Mouser.com
• 1 - 10uF Capacitor - Part 140-HTRL25V10-TB from Mouser.com
• 3 - 4.7k Resistor Network 652-4608X-101-4.7K from Mouser.com (Has an extra resistor, but works fine)
• 1 - D-Sub 25 pin Male - Mouser, RadioShack, etc.
• 1 - Barrel power connector - Whatever works for your power supply. (We used a spare 12V power brick)
• Stranded Cat-5 is sufficient for wiring
• Terminals and male headers are optional, see the page for the circuit.
• Heat sinks for the 5804Bs are needed. We used some aluminum channel.
• Copper clad PC board (We stock up on ebay every so often)
• Etching solution - Ferric Chloride, etc.

We made our own board using the template from the web page. We used similar techniques to the one in part 4 of our iPod Superdock How-To. We reversed the pdf image using Gimp, and printed it onto a laserprinter transparency. This method doesn't create as nice of a trace as the paper, but it's speedier. Clean the board, and keep the paper backing between the plastic and the iron. Once the toner is ironed, just cool it with water and peel.

We etched the board using Ferric Chloride from RadioShack in a disposable Zip-Lock container. It needs to be warm and agitated to work well. The acid and hydrogen peroxide solution etches way faster.

We drilled the board with our drill press and tungsten carbide bits from Drill Bit City. We had to refer to the placement schematic several times to make sure we drilled everything right. Getting the pins holes aligned for the 5804s is a challenge!

If you want to do a toner transfer of the placement mask, do it before drilling the holes. Otherwise the surface is too uneven to allow a good transfer. If you screw it up like we did, you can cheat. Just print the mask onto a transparency and burn holes for the components with a soldering iron. It works surprisingly well.

Next time we'll start building the actual machine and show you how to build some simple and effective slide systems. For now, here's a teaser of what's coming! Good luck!




http://www.engadget.com/2006/06/29/how-to-build-your-own-cnc-machine-part-1/

Lovati Fratelli and new GIANT-83

Founded in 1939, the LOVATI Fratelli Company has manufactured shape edging, bevelling and companion equipment for over 60 years, pioneering today’s automated glass fabrication production.

These machines are specifically designed to meet the stringent requirements of heavy production with superior performance and minimal maintenance, and they are sold all over the world.

For processing shaped glasses, LOVATI Fratelli manufactures a wide range of machines, which starts from simple manual and semiautomatic machines up to the most sophisticated CNC machines.

GIANT-83: The biggest CNC ever produced

Numerical control machine to grind and polish the bevel and the edge on shaped glasses with internal and external curves, straight line edges and mitred corners.

GIANT-83 has 5 axis with linear and circular interpolation of axis X, Y, Z, A for head rotation and B for spindle inclination. The A axis can rotate 360" in continuous mode.

In addition to grinding and polishing of the bevel and the edge, this machine can also perform holes, pin and screw inserts, internal and external milling and routing.

By using angular groups (optional) the machine can make sawing and grooving on shapes.

On the spindle it is possible to stack 1 bevelling wheel or 2 diamond wheels and 1 polishing wheel for grinding and polishing the edge.

More than one glass sheet can be positioned on the working table.

GIANT-83 can process glasses up to 8.300 x 3.210 mm!

The machine is equipped with a particularly strong and powerful head (14 kW) which can have a maximum inclination of 90 degrees (horizontal position).

This characteristic allows to grind the bevel and the flat edge on high thickness glass with any type of required inclination and by using cup wheels instead of peripheral wheels.

The high power of the spindle and the strength and rigidity of the machine whole structure allows to work glass or stone up to a maximum thickness of 100 mm.

The working table can be divided in two sections, each one equipped with 12 positions tool station, with automatic selection for tool withdrawal and deposit.

- CAD-CAM Software

- Teleassistance by modem

- Special bevel polishing system with felt and cerium oxide




http://www.glassonweb.com/articles/article/371/?myKeyword=cnc%20machines

CNC Complements Machine's Abilities

When designing its new Twin Series line of dualspindle production machines, DMG America wanted to incorporate a CNC that would help the machine to give users benefits before, during and after machining cycles.To accomplish this, DMG engineers wanted a control that would run seamlessly in conjunction with the machining center's complex hardware and software packages. They opted for the Sinumerik 840D powerline CNC from Siemens Machine Tool Business .

DMG's extensive software and tool presetter packages for the Twin Series feed data to the Siemens CNC for expanded efficiencies during set up and for predictive maintenance. The machining centers save time and programming costs from the initial stages by enabling users to visualize, on screen with DMG's Programmer 3D turning software, the entire machining process before a tool touches the first workpiece. They can also simulate all machine movements and tool positions, resulting in as much as a 50 percent reduction in setup time. In addition, compiled software data instantly transfers to the CNC, with minimal operator involvement and no programming time.

In process, the Siemens CNC uses its five-axis interpolation and threetool strategy to perform the complex operations in an error-free mode, says DMG engineers. Furthermore, processing speeds are not diminished by automation add-ons for the CNC. These add-ons can include automated workpiece pickup and disposal with a bar-loading magazine, automatic offloading to an integrated conveyor and a fully integrated part-handling system for loading and unloading chuck pieces.

Mark Page, senior applications engineer at DMG says the Siemens control lets him and his customers do what they need to do to integrate software. "It simply allows us more flexibility in programming before the operation, during the entire machining and part-handling sequence and after the job is done, in terms of validation, data transfer and predictive maintenance," he says.

The 840D powerline features a high-performance, industrial PC, 15-in. TFT screen, fast network connections for accessing all data in real time, even to a remote location or on-line service center, on-board diagnostics, error displays in plain text and an ergonomic graphical user interface. The CNC accommodates up to 31 axes and 10 channels.


http://www.americanmachinist.com/304/Issue/Article/False/24780/Issue

CNC machining center features 35hp spindle motor

Taiwan – Awea Mehanronic Co. Ltd is offering model BL4018S, a CNC horizontal boring machining center equipped with a 35hp spindle motor.

The model has a spindle speed of 2,400rpm and a maximum torque of 1,300Nm. It also has a 40-tool magazine with a maximum tool diameter of 250mm, length of 400mm and weight of 15kg. The lubrication and coolant tanks can contain 6 and 200L, respectively.

The product weighs 40.5 metric tons and is fitted with a 1,400x1,600mm table that can carry a load of 6 metric tons.

The x-, y-, z- and w-axes are 4,000, 1,800, 1,000 and 600mm, respectively. The rapid traverse is 10,000mm, for the x-, y- and z-axes, and 5,000mm for the w-axis. The positioning accuracy is ±0.01mm per full stroke and the repeatability is 0.003mm.

Price is given on direct inquiry. There is no minimum order requirement. Delivery is within 90 days after receipt of an L/C.


http://www.globalsources.com/gsol/I/CNC-machine/a/9000000078571.htm

High Speed Machining Software—Mastercam/CNC Software

The company will showcase the new Mastercam Version 8 CAM tools. A highlight is a set of new software tools for high speed machining (HSM). HSM is a new approach to cutting workpieces; the goal is smooth motion with very few sharp corners, allowing for fast, shallow cuts. Combining this specific tool motion with high spindle speeds, high speed machining delivers faster turnaround and a superior finish.

The company offers a suite of fully associative high speed functions, including smooth tool motion on and off the part--Mastercam will move the tool in a smooth are off the workpiece to avoid any sharp angles; variable Z-level cuts--HSM commonly involves finishing a part using Z-level cuts only, and this software can automatically vary the Z-level step-down for a more consistent material removal; continuous Z-level looping--it can loop the tool off of and onto the part between each Z-level cut, eliminating sharp step-down motion; channeling--by using small, continuous looping motions for certain pocketing operations, the software helps eliminate potentially harmful tool burial; ramp contouring--users are able to cut even deep contours with a single, continuous ramp motion, eliminating sharp corners; circle milling--this eases the tool into the material in a circular motion before cutting in a smooth, spiral patterns; and high speed facing--the software provides a special facing routine optimized for high spe ed machines.

The software includes dozens of new features designed to simplify both basic and complex programming. Examples include full associativity in all products, open pocket machining, automated circle milling, faster surface and solid modeling and multi-surface, five-axis cutting.



http://cnc-info.blogspot.com/

CNC Grinding Machine optimizes CBN in shaft production

Designed for volume production of round and non-round shaft parts, Zeus M has grinding length to 950 mm, max diameter of 430 mm, and center height of 220 mm. Product handles workpieces up to 80 kg and combines cylindrical, non-round, plunge, and high-speed peel grinding (HSP) in one machine. It employs polymer Granitan machine bed, galvanic-bond and ceramic-bond CBN grinding wheels, and 130 mm rotary diamond dressing.

MIAMISBURG, OH - United Grinding Technologies, Inc. (UGT) announces the Zeus M, the latest high-performance CNC universal grinding machine for round and non-round shaft parts from Studer Schaudt.
The Zeus M is designed for volume production of camshafts, crankshafts and gear shafts, as well as steering assembly parts, eccentric shafts, axle components, turbo rotors and others. With a grinding length up to 950 mm, a maximum diameter 430 mm, and a center height of 220 mm, the Zeus M handles workpieces weighing up to 80 kg. The Zeus M combines cylindrical, non-round, plunge and high-speed peel grinding (HSP) all in one machine.
A polymer Granitan machine bed provides optimum vibration dampening and thermal stability. The sliding Z-axis with digitally controlled ball screw drive and X-plus Z-axis with hydrostatic guideways offer ultra-precise axes positioning and repeatability for precision shaft grinding. High-frequency motor spindles combined with galvanic-bond and ceramic-bond CBN grinding wheels from 70 mm to 650 mm diameter enable constant circumferential grinding wheel speed of up to 200 m/sec.


http://cnc-info.blogspot.com/

Move over machine tools here come robots

There is a classic failure to communicate in the machine shop. Robots run on brand-specific languages all their own, while conventional CNC machine tools read G-code generated through CAM software. But what if a robot's control was programmed to read G-code directly from a CAD/CAM program?

That robot could gain the functionalities of a CNC machine tool, including full 5-axis contour surface-machining capabilities, and it could be programmed in minutes to work on any 3- or 5-axis workpiece. Current technology typically requires hours, or even days of programming before a robot is ready to work. In addition, machining cells that included such robots could provide a low-cost alternative to machining centers and routers for secondary part operations and could eliminate the work-envelope constraints of those machines when dealing with large components.

Programming Plus Inc. says its Robotic Machining Cell turns this "what if" scenario into a reality. The robotic machining cell hinges on software developed by the New Berlin, Wisc., company that smoothly translates CAM-generated G-code that is ready for a 5-axis machine tool into usable code for a 6-axis robot. No other company in the world has accomplished that, says Tim Brooks, robotic sales engineer at PPI. Programming Plus specializes in CAD/CAM, DNC and shop floor automation.

Programming Plus uses Delcam Power-Mill software to generate G-code for Kuka Robotics robots in its robotic machining cells (RMCs). Since the cells function like machine tools, operators can turn the robot's spindle on and off, change rpms, and override speeds and feeds. Until now, such functions could not be done, says Brooks, because they were not within a robot's control.

Shops typically use conventional robots equipped with spindles for trimming, cutting and deburring around part profiles. But these shops must "teach" robots by moving them to multiple points around parts, and the more complex the part, the longer teaching takes. And teaching robots to go from one part to a different one requires even more teaching. Robots in a robotic machining cell move from one part to the next without having to be taught, and do so with less than 30 minutes of preparation time, no matter what the level of part complexity.

If an operator is unsatisfied with a robot's cutting path in a robotic machining cell, he can change the cutting path in the CAM system or he can manually teach the change and insert it into the toolpath, resave the program, and run it. Also, since robotic machining cells use Delcam's PowerMill software, shops can conduct robot and part-machining simulations to check for possible collisions and obstructions, and do gouge checking prior to running a program. In addition, Brooks says his company's software soon will let shops monitor robots, via cameras, from remote locations over the Internet.

Programming Plus' software offers shops another benefit: resolving problems of singularity. Singularity occurs when all of a robot's axes approach being in line with zero. They increase their speed to keep up, they get to a point where they are moving too fast and, in a way, they lock up and stop. The condition is similar to constant surface footage on a lathe. The problem is that shops can not predict where singularity will happen.

Fortunately, as the robotic machining cell software transfers G-code to a robot, it evaluates the program for physical configurations that might cause singularity. If any are found, the software modifies the program to eliminate them.

Most shops do not associate 5-axis contour surface machining with robots primarily because it would take a great deal of time to teach a robot all the necessary data points. Instead, shops use CNC machine tools. If the parts are large, they are split into multiple pieces that fit on the machines and reassembled after cutting. Alternatively, shops will remove machine panels and doors to mount the portion of the workpiece that needs cutting on the machine, while the rest of the part hangs out or over the sides.

Shops with robotic machining cells can work on whole parts in single setups because the cells do not have exactly defined work areas as machining centers do. Parts can rest on a shop floor or they can be clamped to workholding tables and, as long as the setup is within the robot's reach, they can be machined. In some instances, the robot's reach can extend to 25 ft.

The current ideal application for a robotic machining cell is one that involves large, complex parts to be machined on a 4- or 5-axis machining center that are made of soft materials such as plastics, fiberglass, carbon-fiber composites and the materials used in prototyping. However, Brooks expects to see his company's robotic machining cells being used to machine soft metals by the end of this year.

When it comes to machining metals, there are two factors that hold back most robots: accuracy and torque. Today's robots, on average, are accurate to about 0.004 in. Although most metal parts require precision machining, there are applications in which robot accuracy is acceptable, such as rough machining parts to prepare them for finish cutting on CNC machine tools.

The increased torque that robots require to machine soft metals can be had with more-powerful spindles, but robots have to be strong and rigid enough to handle those spindles, Brooks notes.

Programming Plus uses Kuka robots in its robotic machining cells, and Joe Campbell, director of strategic alliances at Kuka, says several technologies support robot machining. For instance, companies such as Kuka now build robots more mechanically stiff and rigid than they ever have been.

Tighter tolerances in gear trains reduce robot backlash, while finite element analysis and computer simulation tools have helped to remove flex from robot castings. Robots are more intelligent and display tight motion control, and builders can map their inaccuracies better than they were able to in the past.

"We now have a robot platform worthy of machining operations," says Campbell, "It may not sound like much, but considering the mass of a machine tool as compared with that of a robot, today's robots are quite rigid and strong."

Kuka offers a handful of robots for machining, including its KR60-HA, KR210 and KR240 models. The KR60s are currently Kuka's most accurate robots because they feature matched gear sets and other assembly-process techniques that calibrate them for high accuracy. Campbell explains that there is a tradeoff between the material a robot removes and the level of precision it can hold when machining hard materials. A shop that cleans mold marks and flash from die-cast motorcycle wheels, for example, might use a CNC machine tool, but that operation is perfect for robots because it requires precision and minor amounts of material removal. On the other hand, he says that cutting keyways in hard stock is not an ideal application for a robot. " Robots could not do most work that is done on machine tools. But, there are a lot of shops using CNC machines for secondary processes that robots are perfectly capable of doing," says Campbell.

KR210 and KR240 Kuka robot models handle big payloads. And, while milling spindles are not all that heavy, the robots pack ample motor power to maintain position when traveling along cutting paths. "Machine tool builders talk about spindle horsepower. We in the robot business focus on payload capabilities," Campbell says.

The Kuka robots used by Programming Plus easily carry 30- and 40-horsepower spindles. Kuka's strongest robot hefts payloads weighing up to 1,100 lbs. within its 25-ft. reach, and the company is working on even bigger models that Campbell says will open up more possibilities in material-removal applications. Other Kuka prototype models currently in testing feature low travel speeds but extremely high torque and rigidity to further enhance robotic material removal.

In machining applications, robots often use force and torque sensors that allow them to "feel" incongruence or imperfections in surfaces and remove a minimal amount of material to correct them. For example, to blend two surfaces, a robot automatically adjusts the applied torque and force to help it to avoid damaging the surface or removing too much material from the part. Force and torque sensors integrate into a robot's wrist, and the robot controller oversees their operation. Those sensors and the controller combine to allow users to specify the direction in which the robot will apply force, Campbell says.

A typical robotic machining cell consists of a robot with a 5- to 10-horsepower spindle, a covered toolchanger rack that holds 10 tools, a device for determining a loaded tool's length and a laser system that locates workpieces for easy part-to-part setups. Spindle size depends on the application.

A Programming Plus-system robot can change tools automatically. Campbell says toolchanging on the robot side is common, and the company's standard millhead toolchanger is straightforward and simple. This capability makes cell robots self-loading. They remove their milling tool, load a part into the cell, re-attach the tool and cut the part.

"The motivation we hear from customers interested in a RMC is throughput. Most CNC machine tools, unless automated, have low utilization rates, meaning their mill heads are not turning all the time because of setup time and other non-cutting activities. Our robotic machining cells, on the other hand, easily accommodate multiple parts within their work envelopes, allowing one robot to move from part to part for significant throughput at less capital investment," Campbell says.

http://www.americanmachinist.com/304/Issue/Article/False/13386/

CNC band saw has four operating modes

POWER machinery has released to the shark 332 CNC FE electrohydraulic automatic band sawing machine with microprocessor, which can operate in automatic, semiautomatic, semiautomatic/dynamic or manual mode.

The 332 CNC FE electrohydraulic automatic band sawing machine.

It is a CNC machine with multi microprocessor control to manage both the length of the part to be cut as well as the cutting bow itself. It is possible to obtain as many as 32 different lots on the same bar - each of different lengths and quantities.

The 332’s numerical display has 48 characters read on 16 lines to enable the operator to visualise parameters including band speed, the number of cuts programmed and carried out, band thickness, length fed in each stroke, cutting time, amperemeter, band tensioning and general diagnostics.

The unit has a digital read out displaying band tension and an automatic adaptive shearing stress control system that automatically manages the feed rate according to the cutting load.

As a safety feature the machine will automatically shut down in case the band should stop rotating or snap.

The top and bottom of position of the bow can be quickly adjusted, according to the dimensions of the material that has to be cut - this is set with a push of a button on the control panel.

The rotating table has replaceable wear strips in the cutting zone and swings easily due to the large 420mm diameter table mounted on roller bearings.

In semi-automatic cycle, the vice closes when the motor starts, the head goes down to execute the cut, the motor stops and the head returns to position - the vice then opens. Regulation of the head stroke is easily set according to dimensions of material that has to be cut.

The semi-automatic dynamic mode is a versatile feature that allows the operator to quickly bring the blade down to the material manually, then with a click of the trigger within the handle activating the semi-automatic cycle. This allows the machine to make odd cuts without the need to program any parameters.

Automatic style has multiple programming options:

* In single cycle it carries out one only program of pieces that are the same length. Once the number of cuts set has been reached the cycle stops to separate the pieces cut in that lot and an acoustic/flashing alarm is given out.

* Continuous cycle carries out all the chosen program cuts of different lengths, on the same bar, in sequence.

* Single programming carries out a cycle that is programmed directly on the display. The utility step can be used during any cycle: it carries out the face cuts in the bar and makes the first cut and then stop so that the operator may measure the piece cut.

The control display is simple, yet comprehensive. Forty characters read on 16 lines displaying technological parameters such as band speed, number of cuts programmed and carried out, band thickness, length fed in each stroke, cutting time, amperemeter, band tensioning, diagnostics and/or caution messages. The machine can be configured in multiple languages.

The unit’s feeding system operates using a screw/nut with re-circulating balls and stepper motor.

The saw has precision stops for cuts at 0°, 45°, 60° left and 45° right.

A coolant tank sits inside the steel base with two electric pumps so it can lubricate band. As an option, the machine can be fitted or retrofitted with a motorised chip evacuator.



http://www.ferret.com.au/articles/bf/0c03dabf.asp

National Tooling and Machining Association Partners with SourceHorizon, Inc. to Form New Online Marketplace

Greensboro, NC & Ft. Washington MD September 1, 2004 — The National Tooling and Machining Association (NTMA) has announced that it has forged a strategic partnership with SourceHorizon, Inc., one of the nation’s leading online matchmakers between the buyers and suppliers of custom made-to-order parts.

Under the terms of the agreement, the NTMA, representing 1,800 companies and SourceHorizon have created a secure, online marketplace for manufacturing buyers to quickly identify, qualify and negotiate with custom manufacturers. The new marketplace which can be found at www.SourceNTMA.com focuses on adding value and offers a unique blend of information, technology and expertise. The site enables manufacturing buyers to access a pre-qualified supplier base, collaborate during the Request for Quote process and tap into critical services like project management and engineering support on demand. The site enables U.S. custom manufacturers access to new opportunities and other critical information which will help them become more responsive, efficient and profitable. SourceNTMA.com further distinguishes itself in its “pay-for-results” approach to supplier pricing. After a one-time registration fee, qualified suppliers pay a commission on opportunities awarded through the marketplace. NTMA member companies receive significantly discounted pricing. To participate, manufacturers must register online as a supplier, providing specifics about their business, equipment and expertise. After registering, SourceHorizon collects feedback from the supplier’s existing customer base enabling the company to leverage its existing reputation for quality and service into a powerful online marketing tool. To register, manufacturers should log on to www.SourceNTMA.com and follow the simple instructions. Buyer participation in the marketplace is free.

“Our partnership with SourceHorizon on behalf of NTMA members is consistent with our goal of helping our members expand their markets and generate new business opportunities. SourceHorizon offers a unique business-to-business marketing program that will give our members a competitive option in attracting new business in today’s globally competitive marketplace,” said Tom Garcia, NTMA Director of Global Industry Marketing and Meetings.

SourceNTMA.com will be powered by SourceHorizon’s proprietary marketplace technology. The company owns multiple web properties including www.SourceAuthority.com which focuses on U.S. manufacturing. SourceHorizon’s principals, Perry Gathings and Brian Self, said that the new marketplace was founded on the belief that SourceNTMA.com should provide equal value to both buyers and suppliers, enabling both parties to achieve their business goals. “It is an easy and cost effective way to buy and sell services,” said Perry Gathings. “With SourceNTMA.com, suppliers have the opportunity to get exposure to manufacturing buyers at the very moment they need their services. With a ‘pay-only-for-results’ pricing model, imagine the cost-savings SourceNTMA.com can provide. Any time a manufacturer can cut basic expenses the savings go straight to the bottom line.” Self said, “Custom manufacturers who have invested in basic computer and internet technology will be able to easily participate.”

Summarizing their thoughts, Brian Self stated, “We are proud to have been selected as a strategic partner of the NTMA. We look forward to working closely with them to develop new, cost-effective tools that strengthen their members’ businesses and in turn strengthen American manufacturing.”

http://www.cncmachinesinfo.com/articles/category/cnc-tools/

HMC VIPER-grinds and mills turbine blade

On a Makino A55 machining centre, three separate demonstrations at UK Makino agent's technology centre in Coventry, underlined the flexibility of the machine as a platform for producing components by grinding and other metal cutting operations in very few set-ups, or even one hit. Five-axis machining of a nickel alloy compressor blade involved grinding a radial dovetail root form followed by a combination of grinding and finish milling of a small-radius scallop, which the grinding wheel was unable to access. Total cycle time was 5.5 min.

Conventionally, blades are first ground and then set up for a second operation on a machining centre.

Savings in handling, fixturing and cycle time are considerable with the Makino solution.

The second component demonstration involved grinding the fir tree root form for a high-pressure turbine blade from solid nickel alloy in a cycle time of 3.5 min.

Normally, such components are ground from a closer-to-form forging on a dedicated grinder.

The most usual production process for this popular aerospace component is in a 'Nagare' cell comprising, say, 10 separate machines tended by five operators to clamp every part once on each machine.

On a Makino VIPER machining centre, parts generally come off complete in two operations, drastically reducing production costs.

Grinding of a radial seal slot, 2.6mm wide by 7.3mm deep over a 200mm chordal length, formed the third demonstration.

Instead of being produced in Inconel, the part was of a less expensive steel, which in this application is more challenging to grind.

Two small, aluminium oxide wheels were used, rather than traditional cubic boron nitride, one for the outside radius and another for the inside radius to achieve perpendicular groove sides.

Dressing was by NC profiling, avoiding the expense and long lead time of full-form dressing (ideal for fast-make situations).

Two-axis control of the grinding wheel plus B-axis positioning of the component achieved the required contouring of the slot.

Another aspect of this demonstration was the manual-assist loader at the front of the machine.

Components were fixtured outside the machining area and transferred with minimal effort to a zero point fixture on the table ready for machining.


http://www.manufacturingtalk.com/news/ncm/ncm166.html

Replacement Feedback Transducers for CNC Machines

Micronor has introduced its MR200 series Feedback Transducers for new equipment designs as well as replacements for machinery no longer supported by the original equipment CNC machine manufacturers. Feedback units can incorporate any combination of encoders, resolvers, potentiometers, tachometers, rotary limit switches, as well as special interface or control electronics. These feedback elements are readily integrated with precision low or zero backlash gearing in application-specific, compatible packaging. Plug-and-play replacements are available for obsolete units. Machine applications exist across many industries including CNC machine centers, industrial robotics, food processing, medical products, packaging, heavy manufacturing, paper converting and military/aerospace.


http://www.ecnmag.com/article/

Machine shopping

Obviously, shops in the market for a milling, turning, or multitasking machine want the best system for their money. They also want machines that can handle their applications. But beyond these are several other important considerations — some general and some specific to each machine type. By asking the right questions, shops can better sort through their options to make the best choice for their particular operations.


Price is typically the first thing shops examine. However, any financial evaluation should consider the long-term cost of a machine and not just the initial sticker price. "How much is it?" and "How much will you discount?" aren't good opening questions, advises one turning machine OEM.

Instead the end user should begin by showing the OEM/distributor sales engineer parts and part drawings, if possible. According to Bill Jacobson, president of Romi USA, these drawings provide valuable information to help the sales engineer select the right machine. If the sales engineer is unable to help, the OEM should have technical-support personnel that can. The OEM's ability to provide innovative ways for making a customer's parts is crucial in obtaining optimum machine throughput.

Once a shop sets its sights on a certain model, it should ensure the machine is available. If there is a wait, ask if the machine will be delivered in a reasonable time frame, or take several months or longer.

Regarding service and support, shops should question if an authorized distributor is nearby to set up, service, and support the new machine and if repair/service parts are readily available and affordable. Generally, shops want operator training to be part of the package and free telephone assistance for solving everyday problems in operations and conversational programming.

In addition to these issues, buyers should check into the duration of the machine's warranty and where warranty work comes from. If a supplier is unwilling to warrant its product for a year or more, Jacobson recommends finding one that does.

Milling machines
How should shop owners prepare for purchasing a vertical milling machine (VMC) that best fits their individual applications?

Haas Automation of Oxnard, Calif., suggests shops start by determining the reason for buying the machine. Is it a first machine for a start-up shop or a first step into CNC machining? Is the machine intended to expand shop capacity or improve capability to take on new jobs? After sorting through these questions, it's time to go shopping.

VMCs come in all shapes and sizes, and models range from bare-bones 3-axis machines not much larger than a refrigerator to 5-axis behemoths that occupy a good portion of floorspace. What the average shop owner is looking for, however, probably lies somewhere in between. And for most, a standard C-frame VMC fits the bill.

But, warns Makino in Mason, Ohio, some traditional C-frame machines may incorporate structural and axis configurations with over-hung elements, stacked axes, and thin structural elements. These, combined with long unsupported cantilevered distances, can negatively affect stiffness, rigidity, and dynamic distortion, causing vibration and chatter. Such instabilities, inertial factors, and bending movements during cutting degrade surface finish and accuracy, along with cutting speeds and feeds, depths of cut, cycle times, tool life, and machine productivity.

VMC shoppers need to ask at what Y-axis travel a machine shows noticeable side-thrust deflection. This depends, says Fadal of Chatsworth, Calif., on the tolerance of parts. Open-toleranced parts may not show side-thrust deflection unless it causes extreme lost motion, while tight-toleranced parts show minimal lost motion from side-thrust deflection. Tool chatter is one symptom of side-thrust deflection.

What shops need is a heavy cast iron construction and an axis configuration that provides stiffness, rigidity, thermal stability, accuracy, and full-axis-travel support.

Machine designs should have minimal distances to the cutting edge, no axis stackup and overhang, and a table center of gravity within the guideways for good reach over the table without sacrificing stiffness. Ballscrew size, pitch, and servomotor capability also impact machine accuracy, axis thrust, stiffness, rigidity, and cutting performance.

While shopping for a VMC, shops will inevitably face the age-old boxways-versus-linear-guides decision. Mention linear guides, and fast cutting feeds and low friction comes to mind. On the other hand, boxways conjure up thoughts of slow cutting feeds along with deep, heavy cuts. But this mindset is changing because today's linear guideways are more rigid, and new coatings are delivering faster feeds for boxway machines.

Another key machine-design issue with VMCs centers on chip and coolant containment. Fully enclosed splashguards prevent flying chips and coolant from escaping during high-speed machining. However, a full enclosure must provide easy access to the machine table for loading and unloading. This includes overhead crane accessibility, closeness to the control, and a comfortable table height and reach for manual loading.

VMC spindles also have a great impact on machining quality. They come in a variety of styles, but it's crucial that they be stiff and rigid. Shops want spindles that not only minimize vibration but also control thermal change that impacts spindle growth and accuracy.

Design factors that impact a spin-dle's stiffness, rigidity, chatter, and cutting performance include number, size, type, and location of bearings, preloading techniques, balance, and sensitivity to vibration.

With VMCs, the two most common spindle-taper sizes are 40 and 50. According to Ron Kilgore, machining centers product manager, of Daewoo in West Caldwell, N.J., smaller 40-taper spindles usually come in high-rpm models for lighter faster cuts, while the strong and rigid 50-taper spindles are the choice for heavy cutting. But the line between the two is blurring, he adds.

New face and taper-contact systems make today's 40-taper spindles more rigid for heavy cuts. Conversely, new bearing configurations are boosting the speeds of 50-taper spindles. But how much speed is enough?

While spindle speeds in the 30,000 and 40,000-rpm range are available, the most versatile, says Kilgore, is an 8,000-rpm spindle. These handle heavy cuts and, although not the fastest, they do deliver light, fast cuts.

Above 8,000 rpm, a shop is looking at about a 12,000-rpm spindle, which most likely has ceramic bearings. These spindles offer high rpm, but cannot take the heavy cuts an 8,000-rpm spindle can. The main thing to remember for those with experience on lower-rpm machines, advises Kilgore, is that the higher the rpm, the more delicate the spindle. Also, higher-rpm spindles have limited lives, some as short as 2 yr — and some spindle lives are quoted in hr/run time.

For thermal control, VMCs may incorporate large-capacity heat-dissipating spindle chillers that maintain temperatures of spindle bearings and motor areas to minimize spindle-growth effects on part surface finish and accuracy. Some faster-rpm spindles feature core cooling, under-race lubrication, and closed-loop oil-temperature control.

In addition to spindle speed, VMC productivity features such as rapid-traverse rates, cutting feedrates, toolchange time, and spindle spool-up/spool-down times impact part cycle times. Choosing the best machine speeds depends on the material mix of a shop's parts, tooling required, and its idea of how to best produce the part in the least amount of time or at the lowest cost.

"Removing material faster is usually the goal of any machine buyer," says Kilgore, "But, in some instances, a slower feed and heavier cut could outproduce a lighter, faster one."

"A VMC must be considered relative to the field of application," remarks Mal Sudhakar, general manager at Mikron Bostomatic in Holliston, Mass. "A machine useful for high-speed positioning in an automotive application, for instance, is not necessarily of significance for high-speed contouring in a die/mold application."

As with any other type of machine tool, there are basic questions shops need to ask concerning a VMC control. What type of control is it? Is it widely used, reliable, and easy to operate? And is it powerful enough?

Ease of CNC upgrade, according to Fadal, is also a desirable benefit. Removing an entire CNC can be costly, forcing shops to purchase a new machine to get the speed, features, and/or capability of a new control.

Fadal suggests shops ask if the machine's CNC is upgradeable. If so, what elements of the control change out, how labor-intensive is it, does it take a day or a few hours, and can a local distributor perform the upgrade? What are the measurable benefits of speed increases and programming functionality, and what is the true CPU MHz speed?

Once a shop sets its sights on a particular VMC, the next step is considering options to further increase machine performance and better tailor it to suit specific shop applications. Beyond simply finding reasonably priced options, shops should check if the manufacturer offers packages at reduced prices or requires that options be purchased separately.

Haas suggests VMC shoppers consider these useful options: programmable coolant nozzles, chip-auger systems, 4th and 5th-axis rotary tables, and automatic toolchangers (ATCs).

To evaluate a VMC's ATC, recommends Makino, shops investigate how complicated it is. Also, is it reliable, and what size tools can it handle?

In addition to ATCs, VMC buyers should consider pallet changing, suggests Makino. It says that pallet changing dramatically increases VMC productivity by upping spindle use and recommends that the machine control and automatic-pallet-changer pushbutton station should support setup of multiple pallets of work as well as the actual production operation from the front of the machine.

Turning
Tim Rashleger, COO, of Milltronics Mfg. Co. in Waconia, Minn., recommends shops answer some preliminary questions to choose a production-style lathe:

* What swing is required above the bed?
* What is the necessary spindle-bore size and automatic chuck size or collet system?
* Does the lathe need a barfeeder, spindle orient, tool presetter, and parts catcher?
* Should the machine have live tooling — stationary spindle or contouring type — and a tailstock?

Dave Hayes, lathe product manager, of Haas suggests shops focus on the parts they will run to navigate through such lathe-buying issues as horsepower, chuck size, speed, and through-hole size. "A good choice is a machine with the capacity to handle 70% or more of a shop's parts," he says. More casting-type parts require high torque, while shops doing a lot of barfeeding work should zero in on machine through-hole size, spindle type, and speed.

There are basically two styles of production-lathe bases to choose from, conventional slant bed and flat bed (or wedge-style). Slant-bed bases are built up to a slant (45°, 30°, or 60°) that holds a crossrail and turret. A wedge-type lathe's turret and crosslides are mounted at an angle on a wedge block/carriage that moves on rails. "While there are pros and cons with both designs," says Hayes, "they both work."

Whether a slant bed or wedge type, a lathe's base must be a rigid, fairly heavy structure. "Cast iron alone, in some cases," says Richard Lewis, marketing operations manager for Hardinge in Elmira, N.Y., "is sufficient, but in high-accuracy applications, it may not be enough." This is why some OEMs incorporate polymer composites in their lathe bases or reinforce a cast iron base with the material for vibration dampening and thermal stability.

A sturdy machine base also better handles speed. According to Brian Ferguson, turnkey operations manager at Hardinge, high-speed lathe spindles are becoming more popular. While OEMs provide spindles with plenty of torque, a lot of shops are switching from high torque to high speed. The reason is that tooling innovations and through-tool coolant make for increased cutting speeds, so shops looking for a new turning machine may want to consider a spindle that can keep up.

Because lathe spindles hold workpieces, as opposed to cutting tools, they must be rigid, easily adjusted, have good TIR, and be quickly changed over. In addition, spindle designs should not reduce work-envelope space or create excessive overhang.

Lathe spindles secure workpieces using chucks and collets, and the key to increased machine production is a spindle that quickly and easily switches from one to the other. For using collets, most lathes require mounting some sort of adapter in the spindle, but there are those that don't.

In these jaw-chuck/collet-ready spindles, collets seat directly in the spindle and close to the bearings, so there's less overhang. Also, these spindles quickly changeover to accept a variety of workholding collets and chucks. This ability, along with the right tooling and machine-turret style, contributes to how fast and easy a lathe sets up, says Jeff Thomason, an applications engineer at Hardinge. Lathe shoppers must also determine whether or not their machines need tailstocks, and if so, if they should pick a manual or programmable type. Programmable tail-stocks are recommended for shops doing a lot of shaft, end, and steadyrest work.

Programming at the machine is a big issue with turning, and most OEMs have addressed this with features such as 3D graphics/templates, tutorials that walk operators through part programming, and software that that permits machines to operate as either manual or CNC lathes.

Such controls and software are useful for inexperienced operators and those reluctant to try CNC. "In a nutshell," advises Hayes of Haas, "shops should consider a conversational-type control that links manual and CNC programming."

Multitasking
Before heading off to shop for a mill-turn machine, Gerald Owen, product manager of integrated technology at Mori Seiki in Irving, Tex., says shops must have a clear understanding of their production goals. Is the focus on leadtime or mass production? Answering this question is crucial because in some mass-production applications, such as in an automotive shop, a mill-turn machine may not serve overall production needs. And vice versa — shops planning to use the machine as a 2-axis lathe with live tooling are not maximizing the machine's full potential. Therefore, they may want to re-think purchasing an integrated machine.

"A shop owner has to ask himself: Am I setting up for 1 hr and running three parts for a total time of 1 hr, 15 min, or am I trying to produce a million parts at 3 min/piece?" explains Owen. If the majority of time is spent on setup rather than production, then an integrated machine makes more sense, he advises.

Once a shop determines it could benefit from a mill-turn machine, it has to pick the appropriate size, and that is based on as many of the shop's different parts as possible.

"Selecting a machine size based on only one part or job is not always the best way to go," warns Owen.

According to Hardinge's Ferguson, shoppers should also compare capability to machine footprint. For instance, a shop with a part requiring milling and turning wants to complete both sides of the part. So the shop purchases a mill-turn machine that includes a milling head, toolchange system, and other "goodies" for flexibility. However, adding that flexibility may have doubled the size of the required machine as compared to one sporting a turret housing with fixed live tooling. "Keep in mind what a footprint for flexibility is going to cost," advises Ferguson.

However, mill-turn machines with B-axis milling heads do offer one important benefit. With them, mill-turn machines operate as 5-axis milling machines. Because the heads work as a milling spindle and as a toolholder for turning and boring, parts are completed in one setup, and the spindles easily handle off-center milling and compound-angle cuts.

But how does a shop decide whether or not it needs a mill-turn machine with a B-axis spindle head? The decision, according to Thomason of Hardinge, is application dependent. Parts with angled milling, drilling, boring, or tapping are obviously good candidates for a B-axis spindle. In addition, if the emphasis is on overall productivity as opposed to cycle time, a B-axis machine is a wise choice. That's because, while cycle times are longer, cost per part decreases due to less required labor.

If short cycle times are important, most OEMs recommend a 4- axis, twin-spindle mill-turn machine with a Y axis. But keep in mind, these machines don't provide the programmable angular capability of a B-axis head.

Parts with secondary operations and those that run from barstock are well suited for a twin or sub-spindle mill-turn machine. Subspindles deliver matching or slightly less power than main spindles. They sport an additional axis for moving in to meet the main spindle, which allows for machining part backsides and part transfer. Teamed with twin turrets (upper and lower), twin spindles can work on two parts simultaneously.

Lower turrets, says Mori Seiki's Owen, can increase machine productivity as much as 30%, depending on the part. A lower turret with live tooling shortens chip-to-chip times and keeps machines in the cut.

All these turrets and spindles mean more programmable axes. "Some mill-turn machines can have up to nine programmable axes, so programming is a different mindset as compared to a 2-axis lathe," says Owen. He recommends shops deal with an OEM that makes this programming transition easy through support and features such as conversational programming, interference-check software, and CAM post-processors. They should also supply software transfer of programs across ethernet connections to quickly and easily load programs into the machine.

Mill-turn machines let shops change from job to job and quickly adapt to new applications. Going from a 2-axis-turning part to one requiring 5-axis machining-center-type work is no problem for today's mill-turn machines. And their large tool-storage capacities — over 100 tools for some machines — make such job changeovers even faster, so shops can switch back and forth between small-lot/short-run and large-batch/long-term jobs.

Most OEMs agree that prospective mill-turn owners should shop for a machine and tooling at the same time, instead of as an afterthought. This is because mill-turn machine performance is extremely dependent on the right tooling. Shops should consult cutting tool companies that will study the shop's mill-turn applications and recommend tooling that is rigid, quick changing, and applies to a range of operations.



http://www.americanmachinist.com/304/Issue/Article/False/9194/