Posts in Manufacturing

Beating the Competition by Not Making Products

Manufacturing

August 4, 2011

An emphasis on process rather than creating products is the goal for some metalworking companies these days. Given that manufacturing jobs are still being outsourced and domestic and overseas markets for U.S. manufactured products are continually shifting, manufacturing companies such as Sandray Precision Grinding Inc. (Rockford, Ill.) err on the side of caution and do secondary operations and advanced technologies for their customers’ parts, instead of creating their own.
Marc Gouker, president of Sandray, says there are no Sandray products. The company’s strategy is to work on their customers’ parts that require multiple, complex secondary operations, skill sets that can’t be found offshore or elsewhere, as well as advanced technologies.
“We do every kind of grinding possible,” Mr. Gouker says. “We do centerless, OD/ID, surface grinding, flash grinding, double disk grinding—you name it, we do it.” The company processes steel, alloys, aluminum, plastic and powdered metal in the markets of aerospace, automotive and off-road vehicles. Multinational manufacturers the company services include John Deere, Caterpillar and Cummins.
Mr. Gouker runs one of the largest grinding operations in the state of Illinois and has been in business since 1961. The company has 48 employees working in two side-by-side plants of 34,000 sq. ft. total and runs two shifts Monday through Friday that add up to 18-hour days.

Focusing on Unique Services

Sandray receives customers’ parts that need to be morphed into something else to be complete. About 99 percent of everything it does requires several operations. “We’ll do a centerless OD job where we actually chuck off the ID—jobs where we’ll stack as many operations into a single setup as possible,” Mr. Gouker says. “We’re pushing hard, especially on our CNC equipment. We may run 200 or fewer parts on a particular order, but we’ll load up as many operations in a single setup as we think we can (sometimes we take the CNC beyond its purported capability), and run the job. A single setup, faster throughput, closer tolerance and finish consistencies, repeatably perfect part characteristics—these are customer expectations.”
Mr. Gouker is guardedly proud of being a successful service provider. He knows that to remain this way, he must stay ahead of the competition. To do this, he has to invest in the latest advanced technology and always be tuned into ways to make his services increasingly more unique, which usually involves more advanced technology investment and a constant rethinking of how to process jobs.

Technology Perspective

With about 40 grinders in house (some domestics, most from the Far East), many manual machines, and an increasing population of CNC machines, Sandray has equipped itself to meet just about any grinding challenge. “We’ve bought 13 or 14 CNC machines over the past 4 to 5 years,” Mr. Gouker says. “I firmly believe in investing in the latest and best. It’s what keeps us ahead of the competition. The trick is that you’ve got to keep investing, keep learning and keep advancing.
“Our position is to continuously buy new technology that allows us to do what our customers require and our competitors can’t quite do. Our motto at Sandray is ‘to meet or exceed customer expectations,’ which we do by emphasizing quality through the elimination of human involvement and variability by the use of advanced technology. If you don’t keep an eye on the future—if you take a break from the competitive battle—the future will blow by you with a vengeance.”

The Lone Studer

One of the company’s latest investments is a Studer S151 (from United Grinding Technologies), a CNC internal cylindrical grinder for individual and small series production.
Mr. Gouker elected to go with the grinder for many reasons. He’d heard about its speed, accuracy and flexibility from other grinding shops and from customers. He also heard about the value of investing in a Studer from Integrated Machinery Systems (Itaska, Ill.) who sold the machine to Sandray in September 2010.
“This is one case where you really do get what you pay for and more,” Mr. Gouker says. “We knew about the machine’s flexibility. What we didn’t know is how to define this flexibility. We’re doing things on the machine that no one told us we could do.”
The pictogramming software allows the operator to string the individual grinding cycles together while the Fanuc 21i-TB control generates the ISO code. StuderGRIND is programming software for special applications such as form and thread grinding and profiling the grinding wheel for complex workpiece forms. The program is created on the PC and transferred directly to the machine control.
“I don’t do programming, but when we purchased the Studer grinder, I had the programming down in less than a half day,” Mr. Gouker says. “The flexibility is astonishing. If you can imagine a part, the shapes and geometries, the S151 will produce the part.”
Mr. Gouker describes a couple of jobs the company produces. One job is a tractor component for John Deere made out of 8620, heat treated to 53 RC. “We’ll grind an ID, come out of the hole, move over and put an indicating line on the OD, all in one setup,” he says.
A second part running on the grinder requires two concentric circles—a 3-inch diameter hole followed by a 0.5-inch diameter hole. “We use the first spindle, which is usually slower than the others, to grind the larger diameter. Then the machine automatically indexes the grinding spindle turret head 180 degrees to the second wheel head, which then grinds the small hole in the bottom of the large hole at a much higher rpm.
“We’re doing a job now on the Studer, which is not set up to do OD grinding,” Mr. Gouker says. “In the middle of the cycle, I stop the chuck, spin it backwards and move out and grind the OD. It’s like grinding an ID, but from the outside.”

Excellent Service

“I get impeccable service from IMS,” Mr. Gouker says. “I have the IMS service guy’s phone number right on the machine. I can call him anytime from 6 a.m. when I get in until 5 p.m. He’ll either pick up the phone on the first ring, or he’ll call me back in 5 to 6 minutes. It’s absolutely full support, which is very important when you run as many different jobs as we do, and deadlines get shorter and shorter.”
Mr. Gouker says the grinder is the only Swiss grinder in house, and it’s the only machine he’s bought through IMS. “Right now, the machine is still new to us. We’ll get error messages and don’t really know what we’re doing,” he says. “All I have to do is get IMS on the phone, explain the error message or problem, and they can walk me through the situation right on the phone. If that doesn’t work, they send someone out right away. Service like that in this day and age is a real blessing—having someone at your side who knows your machine inside and out and is available to you almost at any given moment.”

Fighting Back

Mr. Gouker admits there were many shops that did not survive the Great Recession because some weren’t positioned to survive and were not strategically diversified. Many had relied on one or two long-time customers doing basic parts—parts their long-time customers soon found beneficial to outsource for cheaper labor. This, then, left them with few options: Buy new advanced technology to make them more diversified and open to more complex jobs, sell the business, merge with another company, or shut the doors and walk away. This applied to shops that made products as well—raw material going in one end of the plant and finished parts coming out of the other.
“We have centered ourselves on diversification from the beginning,” Mr. Gouker says. “We believe the path to success lies in the investment in advanced technology and its creative use. We intend to buy more Studers over time to replace our manual machines and to become more attractive to customers who need multiple operations that we can do in a single setup.”
Mr. Gouker shares some sympathy with those who fell during the Great Recession. His larger point is to invest in the best, and then slug it out with the competition.
“Grinding has always been a very competitive business, even before the recession,” Mr. Gouker says. “However, for those determined, there is always a way through. Position yourself so you can do something your competitors cannot, which involves technology and imagination. Then fight—fight like it’s October 2007.”

 

Name your Lathe

Manufacturing

January 28, 2011

There are many different categories of lathes. Some of the major categories are listed below.

Woodworking Lathes: Woodworking lathes are the oldest variety. All other varieties are descended from these simple lathes. An adjustable horizontal metal rail – the tool rest – between the material and the operator accommodates the positioning of shaping tools, which are usually hand-held. With wood, it is common practice to press and slide sandpaper against the still-spinning object after shaping to smooth the surface made with the metal shaping tools.

Metalworking Lathes: In a metalworking lathe, metal is removed from the workpiece using a hardened cutting tool, which is usually fixed to a solid moveable mounting, either a toolpost or a turret, which is then moved against the workpiece using hand-wheels and/or computer controlled motors. These (cutting) tools come in a wide range of sizes and shapes depending upon their application.

Cue Lathes: Cue lathes function similar to turning and spinning lathes allowing for a perfectly radially-symmetrical cut for billiard cues. They can also be used to refinish cues that have been worn over the years.

Glassworking Lathes: Glassworking lathes are similar in design to other lathes, but differ markedly in how the workpiece is modified. Glassworking lathes slowly rotate a hollow glass vessel over a fixed or variable temperature flame. The source of the flame may be either hand-held, or mounted to a banjo/cross slide that can be moved along the lathe bed. The flame serves to soften the glass being worked, so that the glass in a specific area of the workpiece becomes malleable, and subject to forming either by inflation (“glassblowing”), or by deformation with a heat resistant tool. Such lathes usually have two headstocks with chucks holding the work, arranged so that they both rotate together in unison. Air can be introduced through the headstock chuck spindle for glassblowing. The tools to deform the glass and tubes to blow (inflate) the glass are usually handheld.

Metal Spinning Lathes: In metal spinning, a disk of sheet metal is held perpendicularly to the main axis of the lathe, and tools with polished tips (spoons) are hand held, but levered by hand against fixed posts, to develop large amounts of torque/pressure that deform the spinning sheet of metal. Metal spinning lathes are almost as simple as woodturning lathes (and, at this point, lathes being used for metal spinning almost always are woodworking lathes).

Ornamental turning Lathes: The ornamental turning lathe was developed around the same time as the industrial screw-cutting lathe in the nineteenth century. It was used not for making practical objects, but for decorative work – ornamental turning. By using accessories such as the horizontal and vertical cutting frames, eccentric chuck and elliptical chuck, solids of extraordinary complexity may be produced by various generative procedures.

Reducing Lathe: A reducing lathe is a specialized lathe that is designed with this feature, and which incorporates a mechanism similar to a pantograph, so that when the “reading” end of the arm reads a detail that measures one inch (for example), the cutting end of the arm creates an analogous detail that is (for example) one quarter of an inch.

Rotary Lathes: A lathe in which softwood, like spruce or pine, or hardwood, like birch, logs are turned against a very sharp blade and peeled off in one continuous or semi-continuous roll.

Watchmaker’s Lathe: Watchmakers lathes are delicate but precise metalworking lathes, usually without provision for screw-cutting, and are still used by horologists for work such as the turning of balance shafts. A handheld tool called a graver is often used in preference to a slide mounted tool.

Design mechanism of Lathes

Manufacturing

January 21, 2011

The design of lathes can vary greatly depending on the intended application; however, basic features are common to most types. These machines consist of (at the least) a headstock, spindle, bed, carriage, and tailstock. Better machines are solidly constructed with broad bearing surfaces for stability, and manufactured with great precision.

Headstock: The headstock is required to be made as robust as possible due to the cutting forces involved, which can distort a lightly built housing, and induce harmonic vibrations that will transfer through to the workpiece reducing the quality of the finished workpiece. The headstock consist of the headstock, Speed change Mechanism, House of the main spindle, and change gears.

Spindle: A spindle is a rotating axis of the machine, which often has a shaft at its heart. The shaft itself is called a spindle, but also, in shop-floor practice, the word often is used metonymically to refer the entire rotary unit, including not only the shaft itself, but its bearings and anything attached to it.

Bed: The bed is a robust base that connects to the headstock and permits the carriage and tailstock to be aligned parallel with the axis of the spindle. This is facilitated by hardened and ground ways which restrain the carriage and tailstock in a set track. There are different types of Bed: Inverted V beds, flat beds, combination of inverted V and flat beds.

Carriage: The carriage holds the tool bit and moves it longitudinally (turning) or perpendicularly (facing) under the control of the operator. The operator moves the carriage manually via the hand-wheel or automatically by engaging the feed shaft with the carriage feed mechanism. This provides some relief for the operator as the movement of the carriage becomes power assisted. The hand-wheels on the carriage and its related slides are usually calibrated, both for ease of use and to assist in making reproducible cuts. The carriage typically comprises a top casting, known as the saddle and the side casting, known as the apron.

Tailstock: The tailstock also known as a footstock, is a device often used as part of an engineering lathe wood-turning lathe, or used in conjunction with a rotary table on a milling machine. The tailstock is a tool holder directly mounted on the spindle axis, opposite the headstock. The spindle does not rotate but does travel longitudinally under the action of a lead-screw and hand-wheel. The spindle includes a taper to hold drill bits, centers and other tooling. The tailstock can be positioned along the bed and clamped in position as required. There is also a provision to offset the tailstock from the spindle axis; this is useful for turning small tapers.

What is Lathe and its mode of use?

Manufacturing

January 14, 2011

A lathe is a machine tool which rotates the work piece on an axis to perform various operations such as cutting, sanding, knurling, drilling, or deformation with tools that are applied to the workpiece to create an object which has symmetry about an axis of rotation. Lathes are usually used in woodturning, metalworking, metal spinning, and glass working. A metal lathe or metalworking lathe is a large class of  lathes designed for precisely machining relatively hard materials.

They were originally designed to machine metals; however, with the advent of plastics and other materials, and with their inherent versatility, they are used in a wide range of applications, and a broad range of materials.  In machining terminology, where the larger context is already understood, they are usually called lathes, or else referred to by more specific subtypes names such as tool-room lathe, turret lathes, etc. These rigid machine tools remove materials from a rotating workpiece via typically linear movements of various cutting tools such as tool bit and drill bits.

Most suitable equipped metalworking lathes can also be used to produce most solids of revolution, plane surface and screw threads or helices. Ornamental lathes can produce three-dimensional solids of incredible complexity. The material can be held in place by either one of two centers, at least one of which can be moved horizontally to accommodate varying material lengths. Other work holding methods include clamping the work about the axis of rotation using a chuck or faceplate using clamps.

When a workpiece is fixed between the headstock and the tailstock, it is said to be “between centers”. When a workpiece is supported at both ends, it is more stable, and more force may be applied to the workpiece at a right angle to the axis of rotation, without fear that the workpiece may break loose.  When a workpiece is fixed only to the spindle at the headstock end, the work is said to be “face work”. When a workpiece is supported in this manner, less force may be applied to the workpiece, in case the workpiece rip free. Thus, most work must be done axially, towards the headstock, or at the right angles, but gently.

When a workpiece is mounted with a certain axis or rotation, worked, then remounted with a new axis or rotation, this is referred to as “eccentric turning” or “multi axis turning”. The result is that various cross sections of the workpiece are rationally symmetric, but the workpiece as a whole is not rationally symmetric.

10-bit rotary precision servos

Manufacturing

February 25, 2010

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[Antonb] added 10-bit encoding to a standard servo. He’s removed the potentiometer, separated its shaft and used it to rotate a small magnet. By sandwiching an AS5040 rotatory encoder IC into the servo’s housing he can now measure the precise orientation of the servo horn. This is made easier by his tiny breakout board for the chip. If you want to layout your own PCB you can download the EagleCAD files for this device. Take a look at the final product in the clip after the break.