Solution for unlimited sanding

Have you ever feel annoyed of your stationary sanding machine?

You can’t use it for the long, far area

You have to bring the material

This lead to the limit ability because you can’t use it for the big material or the fixed thing.

In this case, you should buy a portable belt sander for the unlimited sanding.

What to impress:

– Belt sander is very familiar for the woodworker. Nothing can smooth the wood as fast as a belt sander. And a portable model is the handy form of belt sander that allows you to sanding at anywhere and any surface. Space is no longer the problem anymore.

– The second feature you gonna loves this style of sander is its strength. The portable belt sander provides the strongest motor in sanding machine class. That mean you can clear almost the level of material from the lightest to roughest stock.


Weak point:

The portable belt sander strength is also its weakness. It likes a monster that always in the angry status that can destroy anything in the fastest mo.


But can’t deny portable belt sander is the best choice whenever you need the fast and strong sanding machine. So, what is the solution for the disadvantage? The various speed control can easily solve this problem. It provides the convenient system which can dial to the suitable speed, make sure your materials smooth, finer than ever. One more thing you should remember is never put the sander in one place, you must always move it to avoid wood dents and damage.

Our recommend:

Makita 9903 various speed dial belt sander:

This is the best portable tool I have bought and used for more than 12 years. The professional various belt sander you should choose for any DIY and business projects.

Buy a portable belt sander

Porter cable 371K:

With the small stock requires skill for curved and contour sanding, this product is the perfect choice. With the size only 2 ½ inches by 14-inch and compact design. This belt sander enables to do precisely sanding process in a fast way.

Hitachi SB8V2:

The feature I like most at Hitachi portable belt sander is its cordless model that provides the free-of-limit in use. The dust bag includes helps to protect your health and save time to clean work area.

Finally, any product has its own weak and strong point. Comparing to the stationary belt sander, the portable model has the outstanding point in working area and strength. Really good choice for handy and comfortable benefits.

Putting it together

The past two months have been demanding ones for Nicholas J. Nicholas Jr., the president of Time Inc. Since January, Nicholas, Time chairman Richard Munro and Steven Ross, the chairman of Warner Communications Inc., have been hammering together an arrangement to merge Time and Warner to form the world’s


largest media company. Even so, Nicholas likely found time for one of his favorite diversions–taking apart and putting together household appliances at his West Side Manhattan apartment or at his weekend home on New York state’s Fire Island. “I love to see how things work,” he said. “I’ll tinker with anything.”


Nicholas now will have ample opportunity to do just that as he begins to bridge the sharply contrasting corporate styles of Time and Warner. Under the merger agreement, Time Warner Inc. will be jointly run by Time’s Munro, 58, and Warner’s Ross, 61. But Nicholas, 49, succeeds Munro when he retires in 18 months. And Nicholas will run the company with Ross until the older man steps down five years from now.


Nicholas, who is the son of a first-generation Greek immigrant, is a dramatic contrast to Ross, who cobbled together a group of disparate companies into Kinney Services in the 1960s before taking over Warner Bros. in 1969. Nicholas shuns the limelight and he and his psychologist wife, Llewellyn, rarely socialize. A Republican, he describes himself as a liberal on social issues but a fiscal conservative. Colleagues say that they like him personally and that they admire his strong work ethic, curious nature and genuine interest in the journalism side of Time’s operations. Said Roger Rosenblatt, formerly a Time writer and now the editor of U.S. News & World Report: “It is the Greek-American immigrant in Nicholas rather than the corporate executive that drives him. He asks the same sort of questions that Henry Luce would have asked, but without Luce’s monarchical attitude.”


Although first offered a reporting job at Time, Nicholas–known privately by staffers as “Nick” or “Nicholas Nickleby,” after the central character in the Charles Dickens novel of the same name–has earned his stripes on the business side of the company. Armed with a Harvard master of business administration degree, he joined the company’s controller department in 1964 and held a number of financial posts before joining the cable TV operations in 1974. From there, he worked his way up to become chief financial officer in 1982, before beating out other contenders for the president’s office in 1986.


Now, Nicholas faces the biggest challenge of his 25-year career. Observers say that the success of the new company depends upon whether he can smoothly mesh the distinct corporate cultures of the two companies, which are best exemplified by the men now at the top–Time’s courtly Munro and Warner’s flamboyant Ross. But during a series of meetings with Time employees last week, Nicholas was quick to emphasize that he has no intention of allowing video and entertainment to overshadow the magazine side of the business. Keeping that promise while Time and Warner rearrange their many different operating divisions to create a giant new media conglomerate will be a true test of Nicholas’s ability to put things back together again.

Advising by example

Jeannine Guillevin Wood has often been called the godmother of quebec’s businesswomen. It is a sobriquet that the 61-year-old chairman and chief executive officer of Montreal’s Guillevin International Inc. dismisses with a skeptical chuckle. But she has blazed business trails during a career so remarkable that it has entered boardroom lore in the province and beyond. In 25 years, the silver-haired, five-foot-tall grandmother transformed a small family appliance wholesaler in the city’s east end, inherited from her late husband, into a multimillion-dollar electrical distribution empire spanning Canada and stretching into the United States. “It is true that I was one of the first to show that women could do certain things around here, and for that I am glad,” she said, leaning her arms upon a large desk in a modest ofice in suburban Montreal. “But the battle is not yet completely won, for there are still a few people who will not accept us.” Leaning further across her desk, she added with a note of de termination, “Those kind of people I find it best to ignore.”

business woman


Few colleagues or competitors have managed to ignore Guillevin Wood. The company of which she is chairman, chief executive and principal shareholder is Canada’s third-largest distributor of electrical products and a major vendor of automation, security and safety equipment. It employs 1,300 people in 124 offices, distributing 82,000 products to 33,000 customers. Annual sales in the company year that ended last Jan. 31 exceeded $428 million, profits $5.9 million. Guillevin Wood also sits on the boards of several major concerns, including Hydro Quebec, BCE Inc. and Sun Life of Canada. In October, in the face of a recession, her company expanded in the Maritimes–part of a commitment to Canada-wide growth and community service. Also this year, she became the first woman appointed to the policy committee of the blue-ribbon Business Council on National Issues. “You might say that I have won some recognition,” she concedes.


Guillevin Wood’s life might have taken a far different course. Until 1965, she led an obscure but comfortable existence as a Montreal housewife and mother, content to spend the summers golfing and the winters in Florida. But her first husband, Francois Guillevin, died suddenly, leaving her a 15-year-old daughter to care for, as well as control of the family business. At that time, F. X. Guillevin & Son Ltd. was an electrical wholesaler with 35 employees and annual sales of $1.5 million, mostly from the distribution of household appliances. Rather than sell the business, she decided to take the reins into her own hands. “I had no other choice,” she recalls. “It was a good old family firm with a lot of good employees who had given their lives to the company. How could I let them down?”


It was a brave decision, given that she had no business experience of any kind. But over the next 20 years, she acquired 11 other companies and forged working partnerships with firms in France and the United States to fashion what is now Guillevin International. Along the way, she married businessman Keith Wood. She also gained wider recognition. By 1976, she had been twice named “Man of the Month” by Montreal business organizations. Other accolades followed. “There really is no secret to my success,” she says. “It was just the result of plain old discipline and a lot of hard work.” It is advice that she offers by example to others, male or female–the kind of advice expected from a godmother.

5 Best electric belt sander free you from boring sanding work

These top 5 electric belt sanders are selected from hundred products, which provides modern and innovative in sanding process, helps you feel happy and handy while doing this again-and-again job.

1/ Porter-Cable 362V deliver various speed:

porter cable 362v

In an accidental time, I have read the 4 x 24 belt sander reviews and found the Porter-Cable 362V. Actually, this is not my first sander, but it the one that last longest until now. This sander has the big size 4-inch by 24-inch to ensure any materials, any kind of jobs can be solved in easy and simple way. You can smooth and get the finest surface wood or metal by the mobility and powerful mechanism 1,500 SFPM 12 Amp.

2/ Makita– No.1 Portable Belt Sander Brand, Model 9403:

makita 9403

There’is no down Makita always the best choice if you are looking a professional handheld belt sander to use any place for your shop and serious job. The wonderful thing this sander provides is not only the versatile in use but also the quiet operator and super durable component of running for many years. Another 4-inch sander you should consider.

3/ SKIL 3376-01:

skil 3376

Besides portable belt sander, the bench top belt sander proves its advantage by giving the sturdy construction, less vibration and more accuracy. And the SKIL 3376-01 is one in many stationary belt sanders I want to recommend for you guy. Not too cumbrous like others competitors, this product has the handy and well-built appearance. The tension spring adjustment increases the safe in the higher quality. Moreover, the bevel table top are capable of tilting from 45- 90 degrees allows sanding in different angles of materials.

4/ Rockwell RK7866:

The second bench top belt sander in my favorite list is Rockwell RK7866 model. The special feature from this sander is highlight easy to change belt and use also. Some belt sanders usually throw down from the machine while sanding. So the tracking and tension of the product are really essential. And I like this sander lots by this factor and I think you will.

5/ WEN 6502:

The last and the best in the sort of belt disc sander of many passion woodworking and metalworking: WEN 6502. This is high the top product in both prices, quality, service and convenience. At first, the façade of this sander allows you to use in the horizon, vertical and any angle from 0- 90 degrees. This feature provides great advantage to finish your sanding in any projects, even making knives, blades.

Finally, this list of top 5 electric sanders can be brief in the enormous market out there. However, you have a lot of sources, compliments, and reviews before deciding what product you really need. Never buy wrong. That’s all I hope.

Don’t forget food secret- part 2


How do they print the “M & M” on M & Ms chocolate candies?


The company will only say the letters are printed by machine, by a process like offset printing, Feldman reports. Many pharmaceutical companies use a similar process to print their logo on pills. (M & M, incidentally, stands for Mars and Murrie, the founders of the company.)


And why are there more brown M & Ms than other colors? It’s because market researchers found that’s what people want.


Reg. Penna. Dept. Agr.


Why are packaged bakery goods registered with the Pennsylvania Department of Agriculture?


Pennsylvania requires that every baked-goods company selling products in the state must be inspected and licensed to ensure cleanliness and honest weight. They’re not trying to impose their standards on the rest of us; it just costs more to make special packages for one state, so the firms mark all packages “Reg. Penna. Dept. Agr.”


Why doesn’t a drink of water help when your mouth burns from eating spicy hot food?

food part 2

The reason is because oil and water don’t mix, says Cecil Adams in The Straight Dope. The fiery spices in many Mexican, Indian, and Asian dishes are oil-based. They blend with the oil in the food, and when you eat it, the peppery oil coats your mouth and tongue. Water simply flows over the surface. If you’re desperate, drink whole milk (not skim) instead; the butterfat dilutes the spicy oil.


Or eat something bland and starchy along with spicy food, like rice or mashed potatoes, which will absorb some of the oil.


Were Puffed Rice and Puffed Wheat cereal really “shot from guns”?


It’s an old advertising slogan for Puffed Rice and Puffed Wheat, and it’s not too far wrong. The cereal is in a cylinder, under intense pressure and heat; then the cap on the cylinder is released, and the cereal shoots out and puffs up. It sounds like a cannon shot. It’s called explosion puffing.


Now researchers at the U.S. Department of Agriculture are using the same technique to dry vegetables and fruits, such as strawberries. The puff-dried foods absorb water better and have more flavor. Someday we may have puffed fruit on our puffed cereal.


Floating Raisins


How do they keep raisins from falling to the bottom of the cereal box?


Unpopped popcorn kernels fall to the bottom of the bowl, Feldman points out. In cereal, however, raisins are added after the box is more than half full. Then, when the box is jostled in shipping, the raisins get distributed through the cereal.


How do they grow seedless grapes?


By planting a piece of stem from a full-grown seedless grapevine. That’s the only way a plant without seeds can reproduce itself. Seedless grapes originated somewhere in the Middle East thousands of years ago, presumably from a genetic mutation, Caroline Sutton tells us in How Do They Do That? Raisins made from seedless grapes are mentioned in the Bible. The green Thompson seedless grapes we have today, she says, are descended from the first seedless grapevine, as cuttings were transplanted from one vineyard to another over the centuries.


. . . and what about the Thermos?


The Thermos, sometimes called a vacuum bottle, is designed to prevent the transfer of heat between the contents–hot or cold–and their surroundings.


It has a double-walled glass bottle inside, with a near-vacuum between the glass walls, and a cork stopper. Glass and cork conduct almost no heat at all. Because heat can only be transferred through a vacuum by radiation, the glass is lined with a silvery coating that reflects heat and doesn’t absorb it.


The Thermos is a scientific spinoff, invented by a researcher for his work. Sometimes this kind of lab and kitchen crossover goes the other way. The blender, invented for mixing milkshakes, is now used in laboratory research.

Mysteries of food science

There’s a story about the man who was amazed and puzzled by the portable vacuum bottle.

food q&a


“It keeps hot things hot,” he said, “and it keeps cold things cold.” He shook his head.


“But how does it know?” he asked.


People wonder about a lot of things like that. Here are some of their puzzles–and the answers.


What about those electric Lifesavers?


Take some Wint-O-Green Lifesavers into a darkened room with a mirror, and watch your reflection when you start to crunch. If the air is dry, you’ll see tiny flashes of light.


The effect is called triboulminescence. When sugar crystals are crushed, there is a discharge of static electricity–a kind of microlightning. The wintergreen flavoring absorbs this lightning and then emits it again. Wintergreen Necco Wafers do this too. Other flavors emit some light, but it’s very faint.


Green Eggs


Why are some eggs white and others brown or even green?


The color of the shell depends on the breed of hen. It doesn’t affect the taste or nutrition of the egg. Most people like white eggs, which are laid by White Leghorn hens. New Englanders prefer brown eggs, which are laid by Rhode Island Red, Plymouth, and New Hampshire hens.


A South American breed called the Araucana lays eggs with blue and green shells. Health food stores sometimes have them.


Why are hamburger buns thinner on the bottom?


According to David Feldman, author of Why Do Clocks Run Clockwise and Other Imponderables, most buns are baked in pans 1/2-inch deep. In baking, the top of the bun puffs up about 3/4-inch. It’s hard to make a clean slice through the puffy top, so the buns are sliced at the top of the 1/2-inch base of the pan. It’s because the bottom of the bun is so thin that it can get soggy. Eating a juicy hamburger? Just turn it over so the top of the bun is on the bottom.


Why do we get 10 hot dogs in a package but only eight hot dog buns in a package?


Hot dogs used to be sold loose at the butcher shop instead of packaged at the grocery, Feldman tells us. When they started packaging hot dogs in the 1940s, putting 10 together made a nice one-pound package.

Found this post interesting. Don’t miss the next part of it.


Hog dog buns, and other sandwich rolls, were always baked in pans that held eight rolls. This seems to be the reason buns come in packages of eight.

3 x 21 Belt Sander, 3 x 18, and 4 x 24, Which one is better?

If your hobby is creating new stuff, love DIY things especially wood stock, metal and furniture. Then, at least you had once in life doing sanding step and understand how much hard and time this job take. That why I and many woodworkers usually use sanders as the very useful tools to saving time and effort in abrasive work. In the range of sanders, I like to use the belt sander most because of its strength, power and time-consuming function. But it’s a little hard at first to choose the belt size for your plan. That’s why today I’m gonna analytic the basic info between 3 x 21 belt sander, 3 x 18, and 4 x 24 size.

Why is belt size important in sanding?

belt sandpaper size
Belt sandpaper size

If the belt sander can compare as a body, then the belt is the soul of the machine. It’s the most important part in the belt sander that directly contact and grind the materials. Thus, picking the right belt sander is really hard, and choose the right belt size and sand grit even harder.

First, let’s talk about a number of belt size. This tool provides a wide range of size that can make any customers confused from ½- inch to more than 6-inch. The reason why belt sander has so much size comes from the different type portable and stationary machine and various usage of users.

What similar and different in these size?

In the numerous size of belt sander, the most popular size is 3 and 4-inch. These 2 sizes are capable of finishing almost sanding mission such as refinishing floor, abrasion wood, smooth the materials. But, does it all use as same as any type of 3 and 4-inch belt sander? Of course not, they also have the different function and these following tips will help you choose the most suitable one for your projects.

3 x 18 belt sander:

3 x 18 belt sander

This type of tool provides the 3-inch in width and 18-inch in length, which almost is under $100 belt sander in market. These sanders also can deliver the good enough powerful motor and speed to smooth and abrade the light of stock. But it can’t work and even get damage while using with hard wood or rough materials. And in this case, the size just the sign you notice that this kind of belt just uses for easy abrasion work.

3 x 21 belt sander:

Unlike the 3 x 18, the 3 x 21 belt sander in the market appears with super strong motor, high speed and good balance for easily clear any materials even the toughest one. So you don’t have to worry if the sanding job takes too much time from you. However, the bad side is it can destroy your stock just in second. So be careful and combine your great skill with the right tool.

4 x 24 belt sander:

4 x 24 belt sander

This size has the same function of 3 x 21 belt sander but bigger. That’s why if you need a tool that can abrade not only efficient but also faster, this size is for you.


It’s hard at the first to choose the right size and material belt sandpaper for your sanding machine. But, it saves a ton of time and money after that. All the 3-inch and 4-inch belt sander can easy to pick and use, don’t worry. Just learn and experience.

The spirit of boats

Down-East boat builder Bud McIntosh is dead now. But those white oak frames he installed in 1935 still touch the life of Bruce Sodervick, an artist and sailor living in upstate New York. Sodervick watched a McIntosh-built double-ender slowly decline and die in a weedy boatyard corner near his home. Finally he could stand it no longer. He bought the boat.


It’s natural that the classic wood sailboats of a generation ago should attract Sodervick. He has gained national recognition for his sculptures of frames, stems, keelsons and sheet clamps that pay homage to the spirit of boats; his work has been displayed in New York City galleries, in Paris, Toronto, North Carolina, Nebraska, and Tennessee. Libraries, yacht clubs, private collectors and city parks also harbor his “boat spirits.”

viking ship

The world of art, he says, is a peculiar business filled with whimsy, occasional hype and vagaries of fashion that are very different from the rigorous discipline of boatbuilding.


“Marine art is grouped into two types: marine wildlife/illustrational painting and historical replicas,” Sodervick explained. “I can’t do models or replica art. It drives me nuts! Why not just make it a little bigger so you can sail it?


“What causes this feeling, this uplift you get from simply looking at a boat? I see people keep an old wood boat in their yard and just let it go down and down and finally rot away. Why do they keep it? I think it has to do with a world of emotion and feeling that comes from boats and water. It’s something that none of the rest of their modern world is about…this spiritual power is certainly something worth creating about.”


Because they’re not replicas, Sodervick’s skeletal representations of boat “bones” confuse some people. And the interpretations of various art critics around the country notwithstanding, they were not meant to represent shipwrecks, death or decay–at least not most of the time. What this artist-sailor wants is for his work to capture the feeling, the spirit of adventure, and the ageless lure of open water as seen over the prow of a staunch little ship.


Boats predated art in Sodervick’s life by many years, and boats remain a wellspring of creativity for him. “I was a farm kid. Our farm would flood every spring, and every spring we’d go down to the river and collect some free boats. My brothers fixed them up and the ones they didn’t use just lay around. I think I was about 5 when I did my first ‘restoration.’ I poured in some tar to seal her up and then took her down to the cornfield and poled around.


“Then,” he said with a smile, “I discovered the sail!” After that, as Sodervick sailed his scow down to the field’s lee end and walked it upwind again, he was hooked for life.


Art came into his life a lot later, with degrees from Indiana and Southern Illinois Universities. Since 1971 Sodervick has been moored to the faculty of Rochester Institute of Technology and has done most of his sailing on one or another of the Great Lakes.


As a hobby he also has revived a veritable fleet of old Lake Ontario woodies including a 28-foot Yugoslavian-built “Viking,” a 33-foot Chris Craft cruiser, an old gaff ketch built in 1910, and most recently the Bud McIntosh-built double-ender.


A number of Sodervick’s earlier works involved the same carpentry skills he employs in the boatbuilding and repair hobby. Bevels, joinery and steam-bent frames made the inspiration for his wood sculptures obvious. But Sodervick has since moved away from such literal attempts to celebrate the feeling of boats.


Recently he has tried to capture the boat spirit in a more abstract fashion using glass. He employs a variety of techniques including casting, blowing and “slumping” (a process whereby a plate of glass is not quite completely melted down into a mold, leaving a few lumps and irregularities). Sometimes Sodervick combines glass with stone, bronze or other material to create what he calls a “totem.”


He places the bronze or copper backbone, knees and ribs atop a column of stone or cast glass full of swirls and bubbles like clear, frozen water because he likes his works suspended, floating, lifted up like a boat afloat. He does not like to see his sculptures displayed lying on the ground like a bit of sea wrack or a pile of beached whale bones. “I’m trying to exalt the spirit…it’s like that lift you get when you first see open water before you.” Or, he adds with a smile, “like that feeling you get when you first see your boat waiting for you at the dock or mooring. It gives you a strengthening of spirit. I’m trying to catch that soul-strengthening image.”


One dramatic Sodervick work is an 18-foot ship sculpture overlooking Lake Ontario on the State University campus at Oswego. “The Gales of November Remembered” consists of four-by-fours bolted together much as you would build up the deadwood of a large wood boat. Sodervick then sheathed the work as an old-time sailing vessel would be covered in copper. Atop the pillar is a stylistic sailing ship.


It’s not coincidence that, as many art critics have pointed out, Sodervick’s boat sculptures often bear a strong resemblance to the skeletal remains of living creatures. “In a boatyard it’s hard not to feel a bent and worn keel in one’s own backbone,” he says. No doubt that kinship with worn structures is particularly keen at the end of a day of boat repair.


Though he doesn’t create replicas, Sodervick does try to make his work authentic, and puts the same effort and care into a sculpture as he does in renewing 29 steam-bent oak frames, replacing a garboard or laying a new deck.


As of this writing, Sodervick has worked for a year and a half on his latest boat restoration. He has completely reribbed her port side, replaced shear clamp and floors, and now is tackling the sadly rotted decks and a multitude of other tasks large and small. He’s aiming for a 1994 launch and a summer of shakedown cruising around Lake Ontario, then a much more ambitious trek to Lake Superior, Lake Michigan and Georgian Bay. But the call of salt water is strong. In the end, Sodervick will probably take his old Atkins back “home” to the sea, maybe even back Down East to the place of her birth.

Abrasive-water jet job shop thrives

Los Angeles job shop uses multiheaded, five-axis abrasive waterjets to cut aircraft composites, metals

Water jet Machine:

water jet machiningTHE HYDRO-ABRASIVE MACHINING Division of Plasma Cutting Service in Los Angeles is one of the first American job shops to jump into five–axis abrasive–waterjet machining to serve the prime aerospace contractors and others. Their two ASI Robotic Systems (Clawson, Mich, and Jeffersonville, Ind) gantry systems each sport a three-axis head and a five–axis head. Both heads are capable of cutting composites heat–free and cleanly with finishes in the RMS 32–125 range.


Formed in 1947, the company has logged a lot of experience with this technology since it cuts composites and metals for many customers. Now the abrasive–waterjet work accounts for about 75% of the business of the roughly 20-person job shop, nicely complementing their plasma–cutting business. It was also one of the first in the LA area to offer job–shop plasma–arc cutting in 1978. Pcs put in its first abrasive waterjet cutting head in 1986 when it retrofitted twin X–Y Flow Systems (Kent, Wash) PASER abrasive–waterjet heads onto an MG Cutting Systems (Menomonee Falls, Wisc) plasma–arc system.


It’s first ASI five–axis abrasive–waterjet system, with a working area of about 22–ft long x 10–ft wide, went in 1 1/2 years ago, and the second one, which is a bit larger, is new. The older, retrofitted abrasive jet has the capacity to cut through 6–in.–thick titanium. “The cut’s not pretty, but the machine did cut it,” said Michael Woolman, PCS vice president and sales manager. He says that the two ASI Robotic Systems machines have Model 9XD-55 double intensifiers from Flow and the capacity to cut titanium to 8 or 9 in. thick, but for acceptable edge quality, the limit is probably half of that.


“The tolerance capability of the abrasive waterjet depends on the thickness of the work,” notes Woolman, “with [plus or minus]0.005 in. possible in 0.250–in.–thick materials and [plus or minus]0.015 in. in some 1.0–in.–thick materials. Cuts above 1–in. thick are prone to significant taper in the cut.”


Speed is not usually the issue when customers turn to abrasive waterjet–but avoiding a heat–affected zone (HAZ) is. Woolman reports that abrasive waterjet “can be eight times faster than wire EDM but from five to 200 times slower than plasma cutting.”


Plasma cutting of 1.25–in.–thick Income 718 is about 20 times faster than abrasive–waterjet machining. But plasma leaves a significant HAZ which must be milled off in a subsequent operation, so, to make the speed of plasma pay off, a company needs to be able to remove the HAZ for under $50 a part. Otherwise the slower abrasive waterjet is better since there is no second machining operation required. Plasma also requires that extra material be used because: 1) kerf is from 0.200 to 0.750 in., whereas with the abrasive waterjet, kerf is typically from 0.030 to 0.060 in., and 2) so that the HAZ can be milled off. “Sometimes the material savings with abrasive waterjet over plasma can be 20% or more.”


“In most materials, and employing the new PASER II nozzles, we can guarantee a 65–RMS finish. We can do even better by going to a finer–grit abrasive, but that slows down the machine, and the machine is expensive to run.” The machine rate for five–axis work, including programming time, is in the range of $250 per hour. At that rate, companies come to PCS with their really difficult applications. These include formed wing spars and aircraft structural components needing profiling or holes.


Comparing the new cutting heads to the older ones, Woolman states that the PASER II system “gets a better quality cut than the PASER I, employing half the garnet abrasive because of the improved mixing valve. The wear life of the nozzle has been improved by a factor of from 5 to 20 times or more. We can now continuously cut, without changing nozzles, a 1100–in.–long spiral in 7/8–in.–thick steel in 15 hr. Surface finishes on cuts are 30–40% better.”


“Any metal can be cut with abrasive waterjet,” continues Woolman. Some of the unusual metals cut with abrasive waterjet at PCS include high–silicon aluminum, Inconel 718, tungsten carbide to 1/4–in. thick, and the new intermetallic titanium aluminide.


The shop cuts at least 25% nonmetallics, and there have been many successes and a few failures. Some successes include PEEK (polyetheretherketone) used in radar domes and various metal-matrix composites. “We could cut sheets of compressed boron fibers, but not well because the hardness of the boron is close to that of the garnet abrasive. We were unable to cut ceramic armor tile, which is usually cut with diamond saws.”


Mike Woolman says that the programming of five–axis abrasive waterjet is a bit different from programming five–axis milling because there are different operating parameters, and feedrate adjustments are required at different points. For their five–axis NC programming, the company uses NCL software from Numerical Control Computer Sciences, Irvine, Calif. NCL supports five–axis simultaneous circular interpolation, will control the feed rate at any point along the cut, and maintains a programmed standoff distance at all times. NCL will also “project” 2–D geometry onto a curved surface and then machine the contour normal to the part surface.


Two recent jobs


One job for MIT involved cutting a prototype of a coil for a fusion reactor from 7/8–in.–thick steel. The production model will be a sandwich with an interior of copper bonded to the top and bottom layers of Inconel 625. The prototype design went through several changes, and programming the 54–in.–dia irregular spiral took at least 20 hr. Cutting time for the 1100–in. path on the ASI abrasive–waterjet machine was 15 hr. The kerf width was 0.060 in. [plus or minus]0.010 in., and the surface finish was about 65–[Mu]in.


A job that saved a major aerospace prime contractor a lot of money and won the company a commendation from their customer involved cutting an 18–in.–dia hatch and a 3–in.–dia access hole in a series of filament–wound composite tubes of graphite epoxy. The tubes were 36 in. dia x 48 in. long x 0.160 in. thick. One of the previous methods required making five tubes for every four needed, and cutting four hatch covers from the fifth tube and sacrificing the remainder. Another method used a semimanual waterjet process but did not achieve a close–tolerance or good edge quality.


The abrasive waterjet process replaced routing and eliminated the need for the costly fifth tube because PCS was able to achieve tolerances of [plus or minus]0.005 in. around the full contour of the hatches and access holes. The job only required a tolerance of [plus or minus]0.030 in. A surface finish of 32–to 125–in. RMS was maintained.

Abrasive water jet process advances

Abrasive waterjetA series of product enhancements are available for abrasive waterjet (AWJ) cutting systems that address recent shortcomings, according to a report by K. Zaring, G. Erichsen, and C. Bumham, all of Flow Int’l Corp (Kent, Wash), presented at the Sixth American Water Jet Conference (Houston) in August.

In the last couple of years the areas of improvement include: * Rate of wear of the consumable parts of the system, especially of the mixing tube. The tube, which formerly had to be changed every two hours, can now be run for a full shift and still be within several thousandths of an inch tolerance compared to the start of the shift. “This translates to less downtime per shift, higher throughput potential, and tighter cut part tolerances.” * Catcher-tank technology, with the emergence of the self-cleaning catcher. A self-cleaning catcher has a properly sloping bottom that allows spent abrasive and kerf materials to settle and be removed from the tank along with water. The mixture is then sent through a separation device, the water pumped back into the tank, and the solids dropped into a waiting drum for disposal.

image002When the drum becomes full, it is removed and replaced with another, minimizing system downtime for sludge removal. * An “abrasive loss-of-flow” switch is now available as part of the abrasive feed system to detect interruption of abrasive flow. This can trigger a shutdown or sound a warning and is said to be “invaluable when cutting laminated or brittle parts.” * A dehazing device is now available that will minimize the surface “frosting” created during AWJ machining. It works by surrounding the high-pressure waterjet with a low-pressure water stream that eliminates the low-powered shroud surrounding the AWJ high pressure stream. The dehazer is useful in cutting materials with a shiny surface such as brass or glass. * A computer software program called Flowpro provides AWJ cutting data for commonly cut materials from 0.060 to 2.0 in. thick. It allows users to add their own experience to the database, and will calculate cost-per-inch once the user inputs labor, power, water, pump, and abrasive costs.