A flexible tool adapter system can save time and money if properly utilized and designed for maximum power transmission and accuracy in alignment.
A true quick-change system can be set offline and quickly installed, but it must be considered in light of today's and tomorrow's workload.
Custom tools, although usually dedicated to a particular application, can be the best solution if the design and construction of the tool is solid and the application engineering and after-sale support is available locally to service it.
When any metalworking manufacturing facility, whether captive or job shop, makes the substantial investment in a new lathe, it is often looking for ways to streamline the manufacturing process. Smart live tooling decisions will increase machining efficiencies, and finding a supplier of live tools that offers high-quality, high-performance products will allow more flexibility from the first big job and on into the future.
The first tool feature to consider is the output needed. Is standard ER output or quick-change most beneficial? Is coolant through the tool capability needed? Does the tool meet the requirements for precision and performance, including the necessary torque output to complement the machine? Are the tools designed according to the specifications of the lathe manufacturer?
When looking at an ER output, determine if it provides enough flexibility, or alternatively, if a more flexible machining system is needed, which will allow the use of the same tool for different applications. If more flexibility is required, a better choice may be tooling with a system that features adapters for a variety of tools without the cost of new complete toolholder assemblies for each tool needed. However, when looking at such systems, be sure they feature a rigid polygon drive system design to prevent power transmission and alignment issues. Such systems seem appealing because the live tool stays in place and only the adapter and collet get changed out with each new tool. However, less sophisticated - though inexpensive - systems may compromise accuracy. At that point, the few dollars saved will mean very little compared to the resulting scrap and downtime.
If changeover time is critical, such as when working on a family of parts, the option of a true quick-change system might be more beneficial. Adapters can be set offline and be ready to go with minimal changeover time.
When coolant-thru tools are selected, it is imperative to first check the machine specifications to be sure the tool is capable of handling the coolant pressure of the machine. In general, internal coolant live tools should be able to handle 1,000 PSI or more.
If the live tool is constructed with large, high accuracy bearings, the tool will have excellent rigidity and premium cutting performance with minimal runout (0.0002" or 0.006 mm is a desirable goal). The bearings, combined with ground, paired and high accuracy gears, make for tools that are consistent and long lasting. Bore tolerance is key in maintaining proper bearing load - a factor that should never be compromised.
In addition, consider the many applications that can be accomplished with the proper live tool. Speed increasers can be purchased for higher RPM, gear reducers for added torque, adjustable angle tools for compound angles, multiple spindle tools for additional capacity or gear hobbing tools for spline or gear cutting. Most of those items are standard catalog devices, but it is important to consider custom tooling when appropriate and justified by a current or future job. A good tooling supplier will work with customers to produce custom tools at reasonable prices. The supplier must be very reliable, however, so look for one with grinding, finishing and perhaps even heat treating in-house or very closely monitored, to do such work. Additionally, be certain the supplier has local support and tools can be repaired or reworked quickly and correctly.
The workpiece materials are always a driver, especially in industries such as medical manufacturing. Buying a less expensive or lower featured tool to work cobalt chromium and titanium is never a good idea.
On a practical level, always check the supplier for inventory and source of supply. Today, when customers are demanding faster response times and more cost off-loading, expect the same from the tooling supplier. Likewise, application and engineering assistance should be available from local sources to support tool choices.
DIN and ABEC standards are the norm in industry and suppliers should be willing to supply all necessary documentation on request. Shortcuts on quality are never worth the short-term savings.
The bottom line is the bottom line for most people today. However, always consider the future jobs when purchasing tooling systems for new and existing lathes. What might seem a bargain might not be after the first big job is completed.
Authored by Preben Hansen, President, Heimatec, Inc.
For more information contact:
Preben Hansen, President
Heimatec Inc.
16 E. Piper Lane, Suite 121
Prospect Heights, IL 60070
847-749-0633
info@heimatecinc.com
www.heimatecinc.com