Real Axis vs. Virtual Axis In just a few years, mechanical shaft drive systems in web-to-web printing presses have been replaced by "virtual" shafts. Many independent motors have replaced the single main motor. Now, electrical energy replaces mechanical energy in distributing the drives to independent motors for the printing press, web-to-web bonding unit, folding, and cutting units. Independent drive motors offer many specific advantages. For example, users can benefit from the mechanically decoupled design of the printing press. This avoids the transmission of motion via a conventional drive shaft, resulting in stable, high-quality printing. Furthermore, printing presses with their own independent motors are highly flexible in configuration; adding another "roller-to-roller" (BB) or tandem printing press is easy and inexpensive. Below is a detailed explanation of more advantages of this new drive technology. Printing Press Drive Motors Complete Printing Equipment Testing Mechanical testing of roller-to-roller printing presses, previously only possible using auxiliary drive motors, can now be performed on roller-to-roller printing presses. All mechanical and electronic performance can now be checked. The power converter and electronic control unit are integrated into the complete drive motor within the printing press. This space-saving design also allows any faults to be detected during test runs. All components undergo thorough inspection before leaving the printing press, significantly reducing installation time at the customer's factory. Reduced Response Time Independent motors operate within a wider tolerance range compared to a single integrated mechanical drive motor. This is because mechanical components require more time to adjust, and the twisting of the mechanical shaft causes changes in torque transmission. With independent motors, deviations from nominal values ​​are reduced, resulting in faster motor response. AC Motor Control and Regulation To achieve precise synchronization of the printing press unit driven by independent motors, AC motors are employed. The motor position can be queried using an encoder 10 bits faster than its operating frequency, allowing for frequent corrections and more precise motor synchronization. The encoder technology and signal processing are more accurate. Less Paper Roll Breakage When periodic failures occur in the paper roll force, such as when the rollers exert tension on the paper roll, the motor responds very quickly. Maintaining a constant paper roll force within a smaller tolerance range reduces paper roll breakage, leading to stable production and economic benefits. To optimize paper roll force, the development engineers adopted the following basic assumption—even when the printing production line is operating smoothly, the possibility of errors must be considered. Not all printing press components function equally well; differences can exist between different printing press units. For example, in the web bonding unit, imbalances caused by off-circular paper rolls must be corrected. Independent motor drive systems significantly reduce sensitivity to such web paper force issues. Customers have confirmed that web paper force is extremely stable on web presses using independent drive motors, especially during speed changes. Virtual Axes Reduce Vibration With conventional drive shaft methods, disturbances in one printing press unit are mechanically transmitted to other units. With independent drive motor systems, this interaction does not occur, and the mechanical connection is eliminated. Previously, minor disturbances caused by DC motors and longitudinal axes that affected print quality have now been eliminated. More Clear Remote Drive Diagnostics Remote diagnostics can pinpoint potential problems. This diagnostics is based on evaluation of drive data, allowing for various individual drive motor adjustments. This can be seen in the comparison of Figures 2 and 3. This requires close collaboration with system partner Siemens AG—in motor, converter, and control technologies. One outcome of this collaboration is the SIMOLINK MONITOR (SLM), an interface to the SIMOLINK (Siemens Optical Link) drive system's high-speed data bus. This extremely fast optical fiber connects all motors linked to the high-speed data bus and provides drive linkage in practical applications, with a "virtual electronic axis" running through the printing press. This SLM command system performs diagnostics; technicians can connect a laptop to this "diagnostic plug" and periodically track all drives. Using SLM, measurements can be performed simultaneously, quickly and accurately identifying the cause of problems that may change, such as registration variations due to component wear. All data from the drive system can be retrieved online, at the same rate as they occur during the printing process. Further diagnostic possibilities using SLM are expected to develop in the future. Many metrics can be obtained from the large amount of data, comparable to those in the DAX and Dow Jones indices, providing information on paper selection and price trends. Reduced component wear: Robust, surface-ventilated, asymmetrical motors eliminate the need for consumable components like carbon brushes. The internal electronic components of the motor are highly sealed to prevent moisture damage. Dust and other debris cannot enter the motor and cause damage. Simultaneously, the control cabinet integrated within the printing press is sealed to prevent moisture and dust from entering. Heat is directly dissipated by the water cooling system, without affecting the air conditioning in the printing workshop. Fewer changes result in higher performance . In the past, depending on the size and equipment configuration of the printing press, up to 108 different main motors were used. Now, only 8 motors are used. For example, two motors are suitable for various types of blanket-to-blanket printing presses. Because these motors are standard, the possibility of failure is reduced, improving operational safety. Using more but fewer types of motors has the advantage of: the design maturity of individual motors is much higher than that of motors that are almost disposable. This has a positive effect on overall product quality. At the same time, fewer different types of motors simplify warehousing management for manufacturers or agents. A failed motor can be quickly replaced. No post-optimization process is needed . With DC drive motors, it is necessary to run them for a period of time, such as 6 months, to adjust all motors for the printing press mechanism. Currently, the number of mechanical devices has decreased (there is no auxiliary drive motor shaft, and no auxiliary motor), but these devices still require a trial operation phase. Independent motors can compensate for this through their adjustment technology, eliminating the need for post-optimization. Advantages when changing encoders or motors : Nowadays, calibrating encoders or motors at any position on the printing press can be done electronically. It only takes the touch of a button. The starter on the fixed mechanical device reports its position to the electronic drive motor, thus avoiding cumbersome setup work on the printing press unit.