Include Workholding in Your Process Planning

Manufacturing has seen a tremendous renaissance in North America. Increasing demand for shorter contracts and lower volume requirements has generated manufacturing strategies that emphasize rapid change-over, modular construction and versatile units of capacity.

One result of machine tool advances is that we may be faced with only incremental productivity improvements in these technologies going forward. So where will the big gains in productivity and cost reduction come from today? The next frontier for productivity gains could be your workholding tools and processes.

Workholding platforms that allow for easily interchangeable components across product lines can significantly reduce setup times. The ability to change in seconds from one size OD collet to another has been a part of our manufacturing processes for decades now, but an expansion of these abilities to cover alternative clamping schemes including ID clamping and special fixtures can add flexibility and reduce setup times. Having chip-to-chip times approaching 1 second and revolutionary cutting tool technology that remove material at ever increasing rates are terrific, but those gains are lost if we are spending hours—or even half an hour—changing over our fixtures.

Just as the market dictated a shift in machine configurations to address the needs for scalable and quickly reconfigured increments of capacity, so too should workholding allow for the flexibility needed to minimize lot sizes and reduce investments by using the same workholding platforms across multiple machining lines. Workholding designed to change in less than 2 minutes from OD to ID clamping and other adaptations such as a three-jaw chuck can reduce setup times dramatically in many applications. Being able to take these adaptations and use them in multiple machining situations, including turning and milling, further minimize workholding investment and add value.

Hainbuch has pioneered simple, intuitive change-over devices that can be accomplished by the machine operator using common hand tools. Change-over accuracies of 6 micron are easily attained—even when changing from OD to ID clamping. In addition, entire workholding systems can be quickly, easily and accurately changed using systems designed and built for the job, providing superior repeatability.

The move to vulcanized, fuller contact clamping heads (collets) as opposed to spring collets were an advancement in accuracy and holding power. High performing machining plants should also consider how more rigid applications can be realized through ID clamping.

Our research reveals that as much as four times the clamping pressure can be applied with ID products than comparable OD clamping solutions. ID clamping also allows access to more of the workpiece, usually exposing five “sides” of a part to be worked on in the same operation. This can be a huge advantage, especially when using the five-axis milling machines and the multiple axis mill-turn machines currently on the market.

The use of new and harder “designer” alloys, as well as traditional hard materials common in the high-value parts required by the medical, aerospace and energy sectors, among others, are key factors in the need for improved workholding. Advanced workholding devices are designed to take advantage of the speed and power of today’s advanced cutting tools while holding the workpiece securely and reducing vibration that can affect part quality and tool life.

The decision to incorporate high precision, modular workholding into an operation demands major changes in both manufacturing philosophy and operational protocols. It is a process that involves incorporation of the new workholding devices, a broader plant-wide workholding strategy that uses common elements across multiple machining lines and the training of personnel.

It is essential to partner with a supplier that is both capable and willing to guide the customer through the initial assessment and installation process and to provide ongoing support. Both the vendor and customer must be committed to take advantage of the full scope of workholding solutions necessary for success.