How To Reduce Cost of Goods Sold in a Tube Fabrication Shop

The Need 
During the bulk of 20th century most manufacturers in the United States enjoyed a long ride immune to foreign import pressure. As the century approached an end, several industries witnessed the relocation of their manufacturing base. Typical examples would involve furniture manufacturing and the garment industry. Another example would involve bicycle manufacturing. When is the last time you saw a new child’s bicycle for sale that was made in the United States? Exactly. 

So how to compete? One way to stem the tide is to automate. Automation can reduce cost of goods sold. Automation is most often a benefit to those interested in either keeping or regaining manufacturing ground. 

The Transfer Process 
The transfer process can help manufacturers stem the tide of foreign pressure. The transfer process itself can take the form of numerous shapes. Linear or rotation, a transfer machine is able to perform many operations all within a defined cycle time. Take the case of a tube used in an automotive brake line, Figure 1 below. 



Figure 1 shows a typical fuel line used in an automotive application. It consists of 3 bends, 2 flares, and 2 fittings installed before the last flare is made. It doesn’t matter if the bent assemlby has 2 or 20 bends. One complete part is formed every time the transfer machine cycles. Typical cycle times can range form 3 to 8 seconds. That is the beauty of the transfer process. It can drop the cost to produce a product like a lead balloon. 

So how does the transfer process work? From a linear perspective, a transfer machine used to produce the fuel line above might be broken up into several discrete operations. 

Figure 2 below shows a small transfer machine used to fabricate small tubes consisting of bends and end forms. 



Figure 2 (to the left), Shown above is a dedicated transfer machine used to produce fabricated tubular parts - microprocessor controlled, this machine combines several traditional operations into a small foot print – all within a very short overall cycle time 

Each operation is preformed simultaneously on different parts every time the machines cycles. Therefore, when the first end form is being imparted on a tube at the beginning of the transfer process, bend 1 is also being formed, at the same time, on another tube. As each tube is transported from one forming station to the next, an additional operation is imparted on each individual tube. 

At the end of the transfer line, (1) completed part is ejected from the system every machine cycle. As mentioned above, a typical machine cycle is anywhere from 3 seconds to 8 seconds. The cycle time depends on the design of the transfer machine itself and not the complexity of the part being formed. Within that cycle time, a tube might be formed, assembled, and then formed again. Although the sum of the individual operation times might equal 55 seconds, (1) complete part is ejected from the system every cycle. That is the benefit of a transfer machine. 

More Benefits 
Another benefit of employing a transfer machine is that it doesn’t require human intervention between operations. Therefore, big bins of parts between operations don’t exist. Forklift requirement are reduced because the need to move in process parts around is reduced. Worker Comp claims are reduced because what would have taken 18 people now takes maybe 2. 

Charting the Future 
Historically, employing a transfer machine successfully has meant dedicated volume. There has been no other way to see a return on an investment. This is changing. In the 21st century, tube fabricators will see a new bread of transfer machines that are highly flexible. For example, a user interface such as the one shown below can now be employed to program a CNC transfer machine to bend tubes. 



What’s the benefit? Flexibility coupled with reduced cycle time. A typical 6 bend part on a traditional CNC tube bending machine can take anywhere from 18 to 35 seconds to produce. On a programmable transfer machine, the same part would take about 5 to 6 seconds. Moreover, the 5 to 6 second cycle time includes load and unload. 

There are limitation to a CNC transfer machine. Among the concerns are tooling, setup time, and machine interferences. However, with any CNC tube bending machine, tooling, setup time and machine interferences are always a concern. 


About the Author

George Winton, P.E. designs and builds CNC tube fabrication equipment for Winton Machine in Suwanee, GA. He can be reached at gwinton@wintonmachine.com or 888.321.1499

About the Machines We Build 

All of our semi-rigid coax and tube fabrication machines at Winton are designed, manufactured, and tested in-house.  We have a large line of standard products as well as the ability to engineer the best solution for our customer’s needs.  Our experienced sales staff makes sure that our customers can justify their capital equipment investment by offering a solution that is exactly what they need in order to manufacture their parts.  Please contact us today to discuss your project.