The PW-65MED thread whirling machine from Leistritz provides an alternative to performing thread whirling as part of a cycle on a turning center. Compared to this latter approach, the thread whirling machine can be significantly faster, the company says. Most bone screws can be whirled on this machine in less than 60 seconds apiece, even long bone screws in 316L stainless steel or titanium. Three or four turning centers can produce the blanks for a single one of these machines.
The machine has an automatic parts loader and hopper system. Pre-turned blanks with either finished or unfinished heads are dumped into a vibratory hopper that aligns the parts and funnels them to the staging area. Each screw is then measured with a light beam, allowing the proper CNC program to be selected for that screw length. This feature allows screws in the same family to be produced simultaneously, without extra setup.