Most machining for these wire components is accomplished using Swiss-type lathes. Depending on the device manufacturer, the geometries of both ends of these devices differ (they might be straight, wedge-shaped, tapered or slotted). One example is known as introducers, which are components used by surgeons to position organ-supportive slings during minimally invasive incontinence procedures.
Many of the bent medical components the shop manufactures are partially overmolded with a plastic handle. At that point it became readily apparent that the shop needed a more efficient CNC bending technique to keep pace with growing demand.
After successfully developing its manual bending process, however, production volumes for this work increased. It turns out that the only vendor willing to try this complex bending job simply couldn’t handle it, so the shop decided to create a 3D bending process of its own. Having no experience with 3D bending, Marshall Manufacturing searched for an outside vendor to take on that work. After that, though, it was approached to manufacture parts that required more complex helical bends.
The shop was able to handle that work in-house without too much trouble. Initially, the customer required machined parts with relatively simple 2D bends. That customer’s need for bending work years ago proved to be the game-changer for Marshall Manufacturing. Achieving the latter standard has been key to growing the medical side of its business.
It is certified to both ISO 9001:2008 and ISO 13485:2003 standards. It can process numerous materials including stainless steel, titanium, aluminum, brass, bronze, copper and a variety of plastics. The shop does some general machining, too. Today, the 40-person machining business operates in a 23,000-square-foot, air conditioned facility with 60 percent of its work dedicated to the medical industry and 40 percent geared toward filtration equipment (primarily machining plastic core tubes for filtration cartridges). The company began in the early 1950s as a supplier of precision turned parts largely for automotive and hydraulic applications. Marshall Manufacturing didn’t set out to be a specialist in both machining and 3D bending for wire and tubular medical devices. (Traditionally, this procedure is reversed: bending is performed first and machined features are added later, making machining much more challenging.) The shop’s more efficient and effective approach not only enables features to be precisely machined anywhere along the barstock prior to bending, but also ensures that those features end up in their proper locations after the complex bending operations.ġ0 Characteristics of a Valuable Machine Shop It then can accurately bend the parts to the correct profile on its modified CNC bending machine. The process Marshall Manufacturing engineered enables it to machine key features into straight, small-diameter barstock or tubing using Swiss-type lathes or wire EDM units. For this Minneapolis, Minnesota shop, a medical customer’s need for accurately machined and helically bent wire components spurred the development of a proprietary 3D bending process that works hand-in-hand with the shop’s advanced machining equipment. Marshall Manufacturing is a good example of this trend. After all, the goal is to deliver whatever product the customer requires in the quickest, most cost-effective way possible. As a result, an increasing number of them are looking beyond conventional subtractive machining processes to alternate manufacturing technologies that complement their chip-making equipment. That is, customer needs drive decisions about the equipment, capabilities and processes shops bring in-house. By and large, shops don’t shape themselves customers shape shops.