Gambit Corporation Precision Metal Forming

Fourslide Technology Proves Efficient for Small, Intricate Parts

Wire and strip metal parts with multiple bends run quickly with low-cost tooling.

Fourslide technology (also referred to as 4 slide, four slide, and multislide) is an excellent process for stamping and forming small, intricate parts with multiple bends from wire or thin strip metal. Proponents of this unique metal forming technology state that many types of parts that are produced on conventional punch presses could be made at a lower cost with less complicated tooling on fourslide machines.

With fourslide equipment, the part is formed by four forming tools, which slide into the part intermittently at right angles to each other in one cycle of the machine. The wire or strip is first fed through a straightener from a coil or spool, then it enters a punching or forming section. On traditional punch presses, the parts are carried on a holding strip and each bend is performed one die, one punch at a time, often with progressive tooling for complex parts.

The fourslide process is said to save on material costs because it eliminates the standard metal carrying strip. In addition, many fourslide machines are equipped with standard stamping sections with dies for an initial blanking step to cut holes, slots, and notches in the part.

Gambit Corporation, of Rohnert Park, California, near San Francisco, is a contract manufacturer that specializes in fourslide metalforming operations for a variety of diverse clients. Gambit produces a multitude of clips, clamps, contacts, pins, fasteners, brackets, terminals, probes, and flat springs, mostly for the medical, electronics, semi-conductor, and computer industries.

We specialize in very small parts, ones that many shops don't want to do.  Some parts are so small we have to magnify them 10 to 20 times before we can measure them. The tooling also has to be very small and intricate. And, since the parts are so small, it often takes great ingenuity to get a tiny cutter in to cut off the parts after the forming tools do their job. In addition, we can manufacture parts that have fairly close tolerances. Most of our drawings call for tolerances of ±0.005 inch, but we can hold ±0.002 or better on all of our equipment."

An Alternative to Progressive Forming

Fourslide equipment can handle most parts with four to six forming tools, parts that would take eight to ten, or even twelve, progressive punch press stations—each with a separate die. So fourslide machines offer great time and money savings on many parts that need both punching and forming.

We can easily tool very small, intricate parts with our fourslide machines.  Strip thicknesses can be as thin as 0.001 inch up to 1 inch wide by 9 inches long. We can do wire diameter as small as 0.003 inch with a maximum feed length of 9 inches.  One job we now handle was previously being done elsewhere by grinding grooves in a wire-form. We tooled our fourslide machine to punch the grooves and form the part in one operation. We then ran our machines at 200 pieces per minute, which cut the per part cost tremendously.

The benefits of manufacturing small, close-tolerance parts with fourslide technology are many.  Fourslide tooling is inexpensive and machinery runs at very high speeds, which creates a low cost per part for production. For added efficiency, fourslide machines often have dual slides on front and back, so it can cycle as a six-slide machine. Moreover, most fourslide machines also have a form lifter, which moves up and down to pop the part off the center form, or can be used as an additional tool.

Additionally, prototypes can be fabricated inexpensively when only a handful of parts are needed. For example, a prototype setup, without tooling, can be accomplished for about $900, whereas standard hard-steel tooling costs approximately $3,500 for the same part. Gambit builds the prototypes using simple fixturing, then doing each bend separately. During production, the fourslide part will only cost about 1 to 10 cents per part, compared to the standard stamped prototype that could run from $1 per unit to several dollars.

To maintain a high level of quality, Gambit utilizes a vast array of sophisticated inspection equipment for this miniature and micro-miniature type of work. So small are the parts that they have to use comparators, digital microscopes, and even video microscopes with color monitors to view the parts during inspection. All of the inspection tools are linked into SPC (statistical process control) software for production monitoring and analysis.

CNC wire forming machining is reported to be the main competition that fourslide technology is up against. Machine setup time is minimal with wire formers, but programming can be time consuming, depending on part complexity. Additionally, a wireformer can do work on several different planes, while fourslide is mostly a one-plane piece of machinery, except when a form lifter accessory is used to push parts down into a second plane. But, with only one forming tool, wire forming production moves at a much slower pace.

If it's an intricate part and you're only running 1,000 to 20,000 pieces, wire forming might be a less expensive way to go, but for high-volume production runs above 30,000 units, or in the hundreds of thousands, fourslide is the best process.

The disadvantages of fourslide machines are few, but they do exist. About the only bending that cannot be done is coiling to make coil springs. The main drawback, however, is that the machines are usually more time consuming to set up than an ordinary punch press.

Ability to Handle Many Metals

Gambit routinely punches and bends a variety of different metals "from the exotic to the commonplace," including platinum and silver alloys, tungsten, titanium, and nickel through phosphorous bronze. The basic wire and cold-rolled strip and wire steels, including stainless steel, run through the firm's machines regularly. Basically, the metal former can handle almost any metal that's formable.

Gambit's technicians are specialists in the use of beryllium copper strip and tungsten wire forming with fourslide machinery.  One thing we've developed are ways to cut and form very thin tungsten wires, usually 0.008 inch to 0.014 inch, for dot matrix impact printer parts.  Because tungsten usually splinters, we designed some special proprietary cutters and special ways to form it so it would not split or break.

Gambit now has one facility and one employee, but seems to do quite well with the small staff.  The machines are very efficient after they are set up, although it takes anywhere from two hours to two days to set one up, so they run very well on a long run.  One operator can watch several fourslide machines at once very easily, while checking parts randomly.

All of Gambit's six fourslide machines are Nilsons. Unlike traditional punch presses, fourslide machines have very low tonnage, seldom reaching more than 10 to 20 tons. The company's fourslide equipment ranges from four machines that have one- and two-ton capacities, to one four-ton machine and one seven-ton unit. Most of its machines have press sections added to allow for a blanking and punching capability.

The company also has three standard punch presses, with capacities up to 30 tons. Gambit operates the punch presses to make blanks, for simple, flat parts, or for a straight cutoff piece. A Nilson S1F is the largest machine that the firm employs; it can handle up to 0.001-inch-diameter wire and 1-inch-wide strips that are up to 9 inches long. The company is also able to punch out pieces of material that are 0.001 inch to 0.020 inch on the smaller (1-to-2-ton) machines.

Another feature of our company is the fact that we'll take smaller production runs that most people don't want to do.  This is because most shops don't want to make expensive tooling, if they don't get a long run to justify the cost. We're glad to make complex tooling, even if it's for small jobs, like 5,000 or 10,000 pieces. A lot of companies want the large jobs—50,000 to 100,000, or even a million pieces—before they will take the job.

Although setup time can be staggering, production times are usually very fast with fourslide. Gambit runs most of its average-complexity work at about 200 pieces per minute, a moderate rate; yet, under certain circumstances, it will run its machines at 400 pieces per minute. For efficiency, the metal former will often perform two-stage forming with its machines. The process is used for complex parts that need additional forming. In this process, the company does four hits with the four existing forming tools, then the part is lowered and the four tools hit it again, for a total of eight bends.

Whether Gambit is producing parts or solving problems for its customers, the company is committed to turning out quality fourslide parts every time its machines roll.