The control system of the machine tool may become an obstacle to shortening the machining cycle and improving the finish of complex 3D models, aerospace parts or medical device components. When the processor can't keep up with the running speed of the program, the drive will reduce the feed speed of the tool due to the urgent need of information, thus prolonging the machining cycle and causing the tool to work inconsistently. In order to replace the worn and overloaded tools, in addition to increasing the number of times the tool is moved to the tool magazine, it also affects the effective use of the spindle, increasing the workload and finishing time of the fitter. GBICincinnati and MTITechnologies have collaborated on this topic to launch a series of machine tools called “revolutionary”. It is said that these machine tools combine the rapidity of modern control technology with the precision of machine tool movement to form a true constant speed machining system.
Programming with a feed rate of 100 ipm does not guarantee that the tool will run at a speed of 100 ipm. In fact, its speed is always lower than the target feed rate. The reason for this result is the ability of the control system to position the tool in the geometry of a particular part in space, including the tool's height offset, tool radius offset, common offset, and workpiece offset. A complex algorithm that must pass every point of the path as the native tool runs on the workpiece. The control system must also be able to calculate approximations and avoidance movements, as well as have acceleration and deceleration functions.
Most of the control systems currently in use can be traced back to the root cause of this system, which means that it has a history of 30 to 40 years. One of the bottlenecks at that time was the download speed of RS-232 connections. This type of control system can read blocks up to 5000 per s. For many part machining programs, this speed is sufficient, but for complex parts, the speed required is much higher than this speed. When Mr. Carlo Miceli of MTI began developing his own control system, he adopted a completely new approach to PC language logic and efficient information processing. Its product is a CNC system based on modern PC hardware, equipped with a new tool path algorithm, reading speed of more than 5000 / s block. GBICincinnati said that the results have reached the "constant speed" processing requirements, its production speed is fast, and the feed rate is very stable.
When the speed (feed rate) is unstable, some problems arise. When the tool is run through the part, its unbalanced motion will cause different loads on the cutting groove on the tool, which will affect the machining accuracy and surface finish. If the tool is not running fast enough to maintain the minimum cutting load of the tool and friction occurs between the tool and the workpiece instead of cutting, the unstable motion of the tool will shorten the life of the tool. This mode of operation also causes a small amount of breakage in the blade, which causes the tool to heat up and become dull. However, with constant speed machining, the uniform machining speed of the tool through the workpiece will be more uniform and the machining accuracy will be higher, which not only shortens the machining time, but also prolongs the service life of the tool.
In the "revolutionary" series of machining centers, MTI's control system does not generate excessive stress associated with high-speed machining, allowing fluid tools to be machined on the geometry of complex parts.
In the execution of the program, the result of high-speed block processing is that the random error of the control system can be stably monitored and adjusted, enabling the tool to run at a constant speed and achieve a perfect surface integrity. The system uses more than 80 high-speed buffers to monitor the operation of the tool. If the random error is exceeded, the tool movement can be adjusted immediately.
Even when machining very complex shapes, it is said that the speed of the control system, the fine adjustment of the drive and the processing of the tool path enable fast and precise program execution.
