include specially developed, precision- ground inserts, and blanks should be compatible with most types and makes of sliding-head spindles. Although this is a well-established high-volume production process, trying to meet higher production and new component demands requires the use of new tooling technology for more advanced ring con- cepts in thread whirling. An example of this is going from a 15° helix angle to a 30° helix angle on the bone. In one bone screw thread-whirling
example, which involved a half-million units per year in varying small batches, installing the modern indexable-insert tool led to cost savings in machin- ing that considerably improved the competitiveness. Nine times more components were able to be machined before the cutting edge needed chang- ing, when the part dimensions were on their way out of tolerance. In addition to all the machine-stoppage time being eliminated, substantial toolroom time was saved thanks to the ease of cutter maintenance.
Advanced Coolant Application Solves Problems Te coolant supply available in
sliding-head machines today offers new possibilities for improved production of small parts. Replacing the conventional flow of coolant in the machining zone by a high-pressure coolant system provides various machining advantages. Te introduction of this assisted means of cutting doesn’t require complicated, elab- orate installations as standard tooling is available and internal coolant supply
is common practice. High-pressure- coolant machining has been developed continually for some time, resulting in today`s qualified concept. Te big advantage is in improving performance and chip evacuation when machining materials that are demanding from a chip-control point of view, such as super- alloys and low-carbon steel. Te application of a tooling concept
for accurately directing jets of high- pressure coolant into the cutting zone is now available for small-part ma- chining. Today`s solution combines that of precision-directed coolant jets with simplified and secure toolholder clamping. Tis opens up a new per- spective for more efficiently machining demanding materials, especially in sliding-head machines where groups of small tools are in very confined spaces and are oſten difficult and time- consuming to change and set. Both ma- chining and toolchanging is improved with the new system of toolholding in the machine that is equipped with location, locking and connections for the coolant. Te turning tool with high-pressure
coolant typically has three nozzles directing coolant jets to where they are most needed. Te coolant affects how the heat generated in the cutting zone is distributed, the amount of tool wear generated, how chips are actu- ally formed and also the amount of smearing of workpiece mate-
ting edge. Tis has a proven effect on both tool life and chip formation. Chip control is in the machine for secure unmanned production, tolerance and surface-finish levels on the machined component, with manufacturing pro- ductivity improved as a result. Te high-pressure-coolant system is
easy to apply in a machine for small- part machining and tools are easily and quickly changed. Tis is through clamping and release of the toolholder by just one screw and a spring-loaded wedge that secures the holder in the toolpost. Accurate and secure position- ing of the cutting edge is obtained when the toolholder is set up and changed. Combined with internal coolant supply in the holder and a simple, safe con- nection between holder and toolpost, problem-free machining of demanding, long-chipping materials has become a readily acquired means for machining parts in the medical industry. Te single-screw release of the QS-
HP quick-change toolholder usually reduces tool-change times to less than a third—typically from three minutes to one minute. Te clamping wedges ensure quick and safe extraction of the tool
Turning with preci-
sion coolant jets is a means to optimizing
performance. rial that will occur on the cutting edge. Te coolant jets effectively shorten the contact length
through forming a hydraulic wedge between chip and rake face on the cut-
and reduce the risk of dropping it dur- ing handling. Once in the machine, the insert-edge position is automati- cally set by contact between the short holder and the stop. When front and back turning is being performed, the secure insert-edge position will typical improve accuracy through an average of 30% less tool movement.