Customers are transferable if the manufacturing skills can be proven and maintained. When new operators come in and fire everybody and then try to hire people back for less money, they are courting disaster. Even if the judgment they make is that the previous management was a bunch of bozos, adding layers of chaos to the existing complexities of revolving ownership is arrogant and dumb. Usually old companies in manufacturing do not fail because the workers were paid too much, but because they were unmotivated and poorly managed. If workers understand the expectations of the owners and know the negative consequences of not meeting them they will generally produce.

I talk to auctioneers who look at lots of deals of machining firms and they tell me that few viable companies sell for asset value these days. In 2012, a skilled workforce and motivated management team has real value – not Silicon Valley kind of numbers, but significantly more than two years ago – before the world started to turn.

Source: Today’s Machining World

Audacity is vital and ubiquitous in the machining industry. Machinists constantly brag to me that their latest setup has never been done in a particular way before. I walk into shops and engineers beam as they show off the homemade machines they’ve concocted.

Audacious personalities are often found among the most successful entrepreneurs as well. Groupon believed that retailers would be willing to offer their products at over 50 percent off to the masses and that millions of consumers would bite. Paypal believed it could make people pay for items in a way that had never done before and pay a fee for the privilege. Online brokerage firms turned the trading institution upside down by allowing traders to pay $10 per trade without calling a broker. Screw Machine World (Today’s Machining World) believed it could produce a revolutionary trade magazine for the machining industry, something interesting and readable versus the tried-and-true traditional stale trade rag. We were naive to think that advertisers would instantly flock to us for our high quality, despite our refusal to run their advertorial submissions. Had we known how hard it would be to make money in publishing, we probably wouldn’t have tried it and I wouldn’t be posting this blog.

Naiveté is an enabler of audacious ideas. Often it’s easier to try new things when you haven’t ever seen “the way it’s always been done,” or at least haven’t seen the way things have always been done for very long. That may be one reason younger people often have the fresh revolutionary ideas, while the so-called seasoned experts get stuck just doing what’s worked in the past. Historically most societies have preached conformity. Schools, religious institutions, corporations and assembly lines usually like to discourage audaciousness. Kind of sad, but the world can only take so many audacious SOBs, right? Are you one?

Source: Today’s Machining World

Please inform TAITRA  of your interest in meeting any of the companies in the visiting delegation by forwarding the format attached.

TNPCB has decided to issue Show cause notices & take action to disconnect EB power to units who have failed to take action. This process will begin from the coming week.

On behalf of Unit holders, AIEMA has requested TNPCB to give units another two weeks (Till 18-05-2012)  and  hold proceedings to enable Unit Holders to quickly take action & avoid the inconvenience of facing legal hassle

AIEMA  requests Unit holders to go through attached copy of the email sent by CAAIIUC (sent twice to all units by them), and furnish requested data within three days This data is required to study possibility of organizing some central collection facilities to help the units to simplify their disposal process. Units are requested to  immediately file their applications to Care Center, TNPCB at Annasalai Chennai, independently for obtaining approval for storage, Handling & disposal of Solid Hazardous wastes.

M Balachandran
Hon Gen Secretary

• Amb.Indl Estate South Phase
• Vellala Street
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• Ambattur First & Second Main Road
• Southern Avenue Road
• Reddy Street &  South Reddy Street
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We need to make multiple passes back and forth to clean a part, but we need to compensate for brush wear. Cutter compensation has so many stops and starts and weird movement limitations regarding rotation direction and feed direction. There has to a better way.

Done Compensating

Dear Done,
I too have experienced irritation when dealing with cutter compensation. There may be another way, but it depends on your machine.

Some machines have what are called “common variables.” They are variables you can use for part counting, tool life tracking, or other uses. How the machine uses these variables is defined by the program.

I used variables in a similar situation on a RoboDrill machine with a Fanuc control.

My repetitious move was to be along the X axis, so I needed to define the location of the surface on the Y axis. This was programmed in a G57. If I called up the G57 and Y zero, the machine would bring the wheel to a location where the edge of a new wheel would lightly touch the part surface if moved across the part. When the brush wears, it no longer performs adequately.

To compensate for the change in wheel diameter we need to modify the Y position. I chose to use variable 514 for the wear compensation. In the following program excerpt, the program calls up the work shift, subtracts wear value 514 from the Y zero position, stores the result in 524, then moves the part to the new Y location stored in 524. Using the variable in this manner allows the machine to move in both the X+ and X- directions without stopping the spindle. This method can be used for any side of the part with minor changes to the program and math.

G57X0Y0
#524=0-#514
Y#524
G0Z-30.0
G1X100.0 F250.0
X0
X100.0
X0
X100.0

There are some risks involved with this method. For example, if a mistake is made when entering the value into the variable cell, a machine crash could result. An easy solution to this problem is to have the program check the value of the variable against a predetermined min/max value before making any tool move.
In the program example below, the value in cell 514 is checked to make sure it is between zero and 7.01. If the variable check is false, the program jumps to block 778, which stops the program and prints the following message to the screen: #514 OUT OF RANGE

Locate near top of program:
IF[#514GT7.01]GOTO778
IF[#514LT0]GOTO778

Locate after the M30:
N778#3006=1(#514 OUT OF RANGE)

The method as detailed above requires the machine operator to maintain the proper amount of variable value required for acceptable performance results. An automatic method is also possible, but only if the tool wear is predictable and consistent. In the example below, the value in cell 514 is incremented by 8 microns each time the program runs. The increment value can be whatever the expected wear-value per part is. This method also allows the machine operator to override this value by changing the 514 value manually.

#534=#514+.008
#524=0-#534
#514=#534
Y#524

The common variables and math functions can be used for many things. Read your machine manual or contact your machine service company for more information on your machine.

A longer more detailed version of this “Shop Doc” can be found at www.todaysmachiningworld.com.

Mark Bos
Robert Bosch Fuel Systems

Mark Bos is a manufacturing process engineer with Robert Bosch Fuel Systems in Grand Rapids, Mich.

Source: Today’s Machining World

In the 1950s, Dr. Norman Franz, a forestry engineer, was trying to find new ways to cut trees for lumber. He dropped heavy weights into water, forcing water through a tiny hole. He achieved short bursts of very high pressures (often many times higher than those currently used), which enabled him to cut wood and other materials. Unfortunately, he had difficulty creating continuous high pressures and never actually invented production lumber cutter; however, he proved that a focused beam of water at very high velocity had great cutting power. In the 1970s the first commercial use of waterjet emerged for cutting corrugated cardboard. Eventually, waterjets came to be used for cutting disposable diapers, tissue paper and automotive interiors. In the early 1980s, abrasive-waterjet was developed for cutting harder materials like metal and glass.

How the waterjet process works

A waterjet uses the same principle to cut through a sheet of metal as a power washer uses for getting rid of dirt and rust, but a waterjet’s stream of water is 30 times the pressure produced by a power washer. Abrasive waterjet, or abrasivejet, is used for cutting metals to produce components for a variety of functions, such as components for tool and die sets, titanium parts for the aerospace industry and customized parts for motorcycles (like the ones seen on American Chopper). For Chicago Waterjet, one of the most common jobs is roughing out IDODs (Inner diameter/outer diameter materials), which their clients can then finish turn. That way clients don’t have to saw cut out of a piece of round stock and then turn it themselves; this makes the material cheaper and the process faster. Although Chicago Waterjet produces volumes as high as 10,000 pieces, a typical job for them ranges from five to fifty pieces.

Abrasivejet, which can be hundreds or even thousands of times more powerful than pure waterjet, uses water fortified with abrasive particles, generally composed of garnet, a very hard yet inexpensive stone. The water mixture is channeled through a narrow jeweled nozzle of .03-.04 diameter, at anywhere from 2,200 – 2,600 mph, with water pressure generally between 40 – 60 thousand pounds per square inch. An abrasivejet has the capability of cutting within .002 of an inch (sometimes more precisely). Unlike a pure waterjet, which cuts material with water, an abrasivejet’s water abrasive additive is what actually cuts the material. With a pump producing 55 KPSI (an average setting), an abrasivejet can cut a half inch sheet of titanium at the rate of 15 linear inches per minute.

One of the biggest challenges when using a waterjet or abrasivejet is limiting taper. Typically, no matter what thickness or material one is cutting on waterjet, a taper of approximately .005-.007 of an inch per side will result. However, in recent years, an articulating head has been developed, which can reduce taper to well under .001 per side for most applications.

Waterjet is also advantageous because it allows a maximum yield of any given material. Because the kerf is only .030-.040 wide, parts can be nested very closely. Also, waterjet produces no hazardous remains. The water is clean enough to go down the drain, and the abrasive substances along with the minute byproduct of the cut material (small particles) are suitable for landfill. Unfortunately, the water/garnet mixture must constantly be replaced because it is not cost effective to clean and dry the garnet, and the water is not pure enough to be reused without a purification process.

Computer Setup

Sophisticated, networked computer controls make designing a job and programming a machine easy and fast. There is no universal G code as with most conventional CNC machines. The geometric design, along with other specifications based on the type of material, quantity, etc. for the desired product are entered into a Windows based program modeled after an AutoCAD system. The specifications are sent to Windows-based controls on the waterjet machine through a network connection. There is no need to program a computer on the machine, nor is it necessary to carry the program to a machine on a floppy disc. Each waterjet manufacturer has its own user friendly software. Pat Hill of Chicago Waterjet says, “[With this software] all I do is basically tell [the machine] how to apply a tool path to any given geometry, and the machine does the rest. You can be at home on your couch with a laptop with the software, and you will know exactly how long it is going to take you to do a certain job.”

Maintenance

The biggest drawback to manufacturing with waterjets is the maintenance the machines require. Because of the extreme stress the water pressure puts on the machinery, the pumps, seals for pumps, and nozzles all need to be rebuilt or replaced over time. Chicago Waterjet estimates that after 400 hours, they take the machines apart and rebuild them. Because they are unsure when parts will break down, there always has to be someone monitoring the machines, which means lights-out operation is impossible. However, Chicago Waterjet is able to run their machines 24 hours a day, 7 days a week.

As thickness of material increases, the time needed for the waterjet cutting process increases exponentially. Chicago Waterjet advises that if the material thickness exceeds six to seven inches, it is probably best to use a different method, such as wire EDM. Wire EDM is also more accurate and better for a product’s straightness and surface finish but is significantly slower than waterjet. Chicago Waterjet admits wire EDMs are half as expensive to run as waterjets and have the advantage of lights-out machining. For Chicago Waterjet just to run the machines, the operation cost alone is almost $30.00 per hour, not including manpower. Wire EDM is limited to conductive metals, while you can cut almost anything on a waterjet, including a “sandwhich” of different materials stacked on top of each other (see image on right).

Lasers are usually prefered on thinner steels (generally 3/16” to 1/4”) because of their cutting power and because one can use secondary work tables, enabling new metal sheets to slide into position almost instantly after the previous sheet is used up. Waterjets have only one work table. However, lasers cannot cut reflective metals, which makes cutting polished stainless steel a problem. Lasers also  generally cannot cut aluminum because of noxious gasses that the procedure produces (unless the laser has an exhaust system). Finally, lasers produce pieces with a work hardened edge, while waterjets produce parts with smooth edges that are not heat-affected.

Diverse Applications

Waterjets are often used to make lettered signs, create sculpture, remove materials inside train tunnels, cut shapes into bullet-proof glass or cut patterns in stone for floor designs. Waterjet was even utilized to cut into the hull of the submarine, Kursk, to recover the bodies of the Russian crew. If you can imagine the same machine cutting bullet-proof glass and long sheets of diapers with water, you can begin to understand what a versatile tool it is for the market today.

Source: Today’s Machining World

Dear Sirs,

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