McDowell Machining Technologies focuses on providing customised machining solutions for complex parts for several industries such as machine-building, aviation, automotive and truck, oil and gas, renewables, heavy-duty machinery and many more. Using the multifunctional TurnMill MC-series of machining centres from NILES-SIMMONS, McDowell Machining Technologies offers solutions for complete machining of diverse materials from aluminium to inconel, applying multiple technologies and process software.
One particular application implemented by NILES-SIMMONS involved a customised machining concept for an N30MC TurnMill machining centre for the complete machining of valve parts for the oil and gas industry. Featuring external, internal and face machining, the machining centre with a distance between centres of 4.5m was equipped with an additional boring bar magazine.
The machined part had a length of 1.3m, a diameter of 315mm and was made of C22 in connection with welded elements of inconel 625. Such mixed material machining always involves huge demands on the technology and the tooling concept. This was particularly true in this case, as the part required a surface finish of Ra0.2.
The external machining technologies that have been used for the process were turning, milling, drilling, gun drilling, finish-boring, reaming, thread turning and burnishing by using a diamond-burnishing tool.
When it came to the internal machining processes, NILES-SIMMONS worked in close cooperation with Sandvik Coromant using the Silent Tools™ Plus boring bar with a diameter of 100mm. With that, it is possible to display the cuts in a closed-door-machining process and evaluate the process accordingly. The boring bar can determine the temperature, displacement, insert breakage and vibration parameters while machining. This allows all important data to be checked and documented constantly during the machining process.
Consequently, the machine, parts and tools are protected from damage and collisions. Furthermore, optimised cutting values and technologies can be used, which increases process reliability and reduces machining time. While machining inconel, tool life of up to 30 minutes could be achieved. Dynamic Turning was successfully applied with the support of Mastercam software. This allows the chip formation to be optimised and the deflection forces to be controlled. The combination of sensor-supported monitoring of the processes by the tool in a firmly clamped tool cassette and targeted action has made it possible to implement this machining cycle in automatic mode.
The internal machining process was completed by highly precise surface finish using ‘FLEX HONE’ honing brushes. The whole process was finalised by implementing face machining, drilling, tapping, countersinking and gun drilling of a diameter of 6.35mm over a length of 1.3m in seven steps. This included a deep hole drilling process of 205xD.
This highly automated process involved an advanced level of process automation features that enable closed-door machining without operator intervention. These features include automatic change of all tools and boring bars, in-process and dynamic
measurement of the machined internal and external areas, including runouts and achieved surface roughness, automatic detection of the welded inconel layer with non-contact scanning for an optimised cycle time. It also incorporated intelligent operator guidance using an additional monitor with regard to premature tool change, media filling, chip disposal and further predictive process measures.
This application underlines NILES-SIMMONS’ expertise in the field of customised machining solutions for highly complex parts and projects. The interaction of a highly developed machine with the necessary and suitable process automation procedures, an efficient machining and tooling strategy as well as individual adaptations to the respective customer requirements is the strength of NILES-SIMMONS and Machining Technologies.