Just like a car or a machine, the human body benefits from the technological progress of small parts turning equipment. Precision and stringent requirements for safety and stability are essential in the medical industry. In fact, the demands made on surgical screws (bone screws, maxillary-facial screws, implants and so on) and bio-implants can be much greater for the human body than for many industrial and commercial product applications.
Tornos Technologies (Brookfield, Connecticut), manufacturer of “Swiss-type” single-spindle automatic turning centers and multi-spindles, has developed technology to serve the needs of specialized industries, and medical is one of them. Its “Deco” concept, launched in 1996, is based on a different numeric control concept, coupled with programming software for a Windows-based PC. According to the company, some of the strong points of the system include the kinematics of the turning machines themselves, which provide simultaneous operations with up to 12 axes; a system for pre-setting stationary and rotating tools, processes and tooling devices for certain machining operations, such as external and internal thread whirling, high speed milling, high pressure drilling and units for angular implant parts; macro programming; and tool life management.
As a case in point for the medical industry, angular dental implants are impossible to machine on conventional CNC turning centers. Although many can perform three-axis interpolation, generally, the cutter cannot be offset to the center line of the part and in the correct plane to produce these angular parts.
With Tornos’ model Deco 13a, for up to 16-mm diameter parts, manufacturers can completely machine these complex dental devices in a single setup. With two “C” axes, the Deco 13a offers up to 12 independent axes of motion, all of which can operate simultaneously. There are multiple rotating tool positions on both the main spindle and subspindle, allowing milling, drilling and thread whirling operations on both ends of the part. Thread whirling is accomplished with an easily integrated attachment. The critical component for the specific angular dental implant parts is Tornos’ angular tool attachment. The angle can be adjusted to generate the correct part shape from 0 to 90 degrees. This attachment, with rotating mill/drill tools, can be used on both the main and subspindle. In addition to all of the benefits associated with one setup machining, such as the reduction in total production time and better geometric tolerances, these rotating milling cutters impart a high surface finish with both rough and finish passes during the process.
The TB-Deco software was also enhanced with special macro subprograms dedicated to milling these angular implant parts. The macros simplify complex compound programming. By plugging in some known parameters, the milling points, feed rates and complicated incline calculations are all done automatically with this sophisticated software.