CoroTurn TR provides a solution for accurately securing the position of inserts in the tool holder. Perpendicular grooves in the under-side of the insert and matching rails (T-Rail) on the tool holder prevent any movement of the insert in the seat when cutting forces act on the cutting edge.
The problems that CoroTurn TR addresses are those of the deterioration of accuracy, unnecessary tool wear and loss of productivity due to the deflection of cutting edges during machining. The bonus effect is precision location of the insert in the tool holder that positively affect tool setting and off-sets in the machine.
Machining carried out using newly developed CoroTurn TR inserts indicates that the locating system is rigid and does not allow insert movement in any direction. As a result, close tolerances can be maintained more consistently as the insert cutting edge, even as it wears, does not deflect from its originally set position, thereby generating satisfactory dimensions throughout tool-life. In some applications, more than four times longer tool-life has been achieved compared to the previously used conventionally clamped inserts.
The obvious beneficiaries of such a development are manufacturers of precision components. Components can be machined to close tolerances and better surface finish, both of which are maintained consistently and considerably longer.
Productivity does not have to be compromised by having to machine at lower cutting data and off-set stoppages are reduced through more consistent and predictable tool-life and improved accuracy. However many medium turning applications also benefit from the non-movement and indexing accuracy of within plus/minus 0.05 mm provided by CoroTurn TR.
Combating the primary problems
To begin with, profiling with pointed (D and V) inserts has been addressed with CoroTurn TR as long inserts, often used for profiling operations, are more prone to the effects of cutting forces that lead to movements of the insert.
These problems typically appear in various in- and out-copying operations and when machining forgings or castings with varying working allowance, hardness of skin and tool paths. No cemented carbide shims, as with conventional clamping, are needed with the system because with no insert movement there is no wear or deformation to speak of in the seat.
CoroTurn TR inserts are today available for steel and stainless steel operations to solve what is now becoming a more discernable problem in a growing number of turning applications. The new insert technology can also be seen as providing new possibilities in upgrading medium to finish turning generally as well as profiling operations that are being subjected to increasingly closer limits and competitive pressures.
The development of CoroTurn TR is also in line with developments of multi-task machines, where flexible, high-precision tools make better use of these machines by contributing towards complete machining of components in one set up.
The CoroTurn TR inserts are available from Sandvik Coromant.