Winton Machine Co.

Columnist George Winton discusses a way to combine two operations into one seamless process by adding a drill to a CNC tube bender.

Seeing bins of parts lying around in your shop? Maybe it’s time to get away from the large-batch method and try one-piece flow. Rather than make a large quantity of Component 1, then Component 2, then Component 3, while a welder downstream waits for Component 3, you could set up a system of one-piece flow that sends a kit of three components. The key to implement this strategy is the bender software.

Large-radius bends are used in many places, such as appliance handles and automobile components. For measuring large-radius bends, fabricators have at least three options: go/no-go fixtures, entering the bent part’s measurements into a CAD program and using it to calculate the radius, and a depth gauge.

Mobile phone systems are mainly electronic, but a fabricated tube plays a critical role—known as a waveguide, this rectangular tube connects the transmitter to the antenna. Precise bending and forming are critical to manufacturing a waveguide that provides a strong, clear signal.

Punching a hole in a tube is one thing; getting the slug out is something else altogether. Even if most of the slugs exit without a problem, the occasional hanging slug can cause a serious problem. Two methods are mechanical force and air pressure.

Accounting is straightforward, but it’s not iron-clad; fabricators have latitude in the accounting system they use to bid on contracts. A bottom-up approach, one that analyzes all the costs that go into making a component, is suitable for many parts. A top-down approach looks at the part and asks how much the market will bear. Choosing one or the other is a matter of understanding the market for the part.

A tube bender can be considered a collection of power presses and, as such, it needs more than just a few conventional barriers between the operator and the machine. Safety mats, interlocked switches, emergency-stop switches, and interlocked side plates are a few of the safety devices available to machine tool manufacturers.

Whether a bending process starts with a cut length of tubular product or a coil, gravitational or torsional forces can lead to unwanted variations in the finished product. In the case of gravity, tube supports can counteract it; for torsion, it’s a matter of matching the coil’s output to the bender’s input.

Loading and unloading tube for fabricating often is a manual process. Because labor rates in the U.S. are higher than those in many other countries, manual loading and unloading isn’t competitive. Using an automatic loader/unloader can change that, moving an operation from red to black.

Vertical compression tube benders have been around for more than 50 years (see Figure 1). Historically associated with high-volume bending, these benders continue to play a role in production environments where parts have just one or two bends. Also known as press benders, they have stood the...

Using a mandrel is helpful for maintaining a tubes profile when bending. Without a mandrel, bending forces tend to distort and flatten tubular workpieces.

Bending serpentine profiles—successive 180-degree bends, which typically are used in refrigeration systems—can be a challenge. By their nature, they tend to cause interference among the various bend dies, and they can be difficult to handle. Good planning in selecting a bender, planning the process, and paying close attention to infeed and outfeed options, can help make a serpentine project successful.