A Solution To Multi-Spindle Challenges

There is no argument that the conventional cam-driven multi-spindle automatic can produce high-volume turned components faster and more efficiently than any other technology available.

Having spent most of my adult life in the high-volume turning industry, I reflect upon the role played by the multi-spindle automatic, both in the past and as it applies to today's demanding and fiercely competitive market environment.

There is no argument that the conventional cam-driven multi-spindle automatic can produce high-volume turned components faster and more efficiently than any other technology available. This concept was well suited to the time when long production runs were prevalent. Over such long runs, the cost of setup becomes a small percentage of the overall cost to produce the component.

Times have changed, however. The challenges facing our customers are daunting. Pricing pressures from the low-cost markets have tremendously impacted margins if they haven't taken work away entirely. Lower volumes, a higher product mix and JIT have challenged the flexibility of the conventional multi-spindle shop. More complex components with tighter tolerances statistically applied are pushing conventional multi-spindle technology to the limits of its capabilities. In addition, we are experiencing a severe shortage of qualified multi-spindle operators and setup personnel.

All of these factors have our customers scrambling for answers to meet and overcome many of these challenges. For some, the answer may be simply to upgrade to newer and more capable equipment. For others, the application of CNC technology may be in order. However, we at Euroturn, believe it is the level of CNC technology that should be evaluated, specifically with regard to integrating a full CNC multi-spindle into a conventional cam multi shop.

There are many things to consider when applying such technology. Shops who have experienced this integration first warn of the “culture shock” effect. The technology and the processing thereof require a much different approach than what they were accustomed to. Subsequently, their experience is one of a long and painful learning curve. Second, they warn of the equipment cost and support requirements. Many CNC multi-spindles approach or exceed the $1 million mark. This requires the user to charge a machine rate of up to or in excess of $200 an hour. The requirement of a “support system” involves setup, a programmer and an electrical person for control and electronic troubleshooting. Finally, partly because of the nature of the components required to support the hourly rate and the complexity of the technology, they typically run one man to one machine. However, they state that based upon their expectations of quick change-over, they were somewhat disappointed.

This is not meant to disparage the CNC multi-spindle. There are many well-engineered offerings on the market providing solutions to the challenges as previously stated. Cam machine setup and operator personnel are difficult if not impossible to find, yet there seems to be an abundance of CNC technicians. When working with tight tolerances in difficult materials, the ability to offset for tool wear on the fly and within microns provides higher efficiencies yielding higher productivity. Also, the application of CNC features can allow the completion of complex components in one chucking, reducing or eliminating secondary operations. There is no doubt that the CNC multi-spindle will play a significant role in our industry's future. However, the application of the technology and the associated costs do not necessarily apply in all cases, nor can it be justified. There exists a solution, however: the hybrid multi-spindle.

The hybrid multi-spindle can bridge the gap between the limited conventional machine and its highly capable but cost-challenging CNC counterpart. Based on experience at Euroturn, the hybrid can provide the customer 90 percent of the benefits of the full CNC multi at lower cost. For those components requiring tight tolerances and finishes, or where offsetting for tool wear is important, Euroturn can supply CNC slides in up to three positions. These slides are capable of being retrofitted in the field. Additionally, servo technology for the replacement of cams with PLC-controlled drives, provides accurate motion control, and when coupled to standard attachments, will provide our machines with increased capability to produce complex features. With the addition of three-axis CNC backworking and spindle orientation, the possibilities abound.

At Euroturn, we have successfully applied servo/CNC technology to our conventional machines providing our customers increased capabilities at affordable prices.

Yes, the CNC multi-spindle may well be the future workhorse of the screw machine industry, but we have to live and compete in the present.