further. “Our goal was to make the tool more ergonomic and even easier to use – without compromising performance or robustness,” says Andreas Keller, Head of Development at Signode Switzerland. Before taking on his current role, he managed the development of the BXT4 as project manager. A new concept One of the most important innovations concerns the mechan- ical concept. In previous generations of the tool, the drive, gearhead, and tensioning wheel that acts on the strap formed a fixed assembly. With the BXT4, Signode chose a new ap- proach: part of the gearhead and the tensioning wheel move to allow the strap to be inserted. This enlarges the opening, makes it easier to insert the strap, and changes the load dis- tribution within the mechanism. The effects extend beyond ergonomics. The new concept changes the forces within the mechanism, allowing individual components to be made lighter and new materials to be used. At the same time, the additional weight of the new, more pow- erful battery generation could be offset elsewhere. The result is a tool that remains comfortable to hold de- spite its greater performance and places noticeably less strain on the operator during everyday use. Where motion control comes in The new mechanical concept also changed the requirements placed on the drive and control system. For maxon, this marked the beginning of a new development phase in the project. Inside the BXT4, a single drive performs several tasks. It precisely positions kinematic elements, delivers high torque for tensioning and maintains a constant speed when welding the strap. For Kim Zimmermann, Key Account Manager at maxon, it is precisely this interplay that makes the project so compelling: “For us, the BXT4 is an exciting project because we can supply the complete drive system – from the motor and controller to the application control system. This allows the individual components to be optimally matched.” While Signode is responsible for the overall mechanical concept and integration, maxon contributes its full motion control and application expertise, along with perfectly matched components. Advancing the solution together One example is the switch to maxon’s ESCON2. During de- velopment, Signode decided to adopt maxon’s new platform at an early stage – even before it was officially launched. “Using the new platform certainly involved a degree of risk. We decided to go ahead nevertheless – partly because experience had shown us how effectively we could work with maxon.” The new motion control platform opened up additional possibilities for the design of the overall system. Among other things, the ESCON2 platform enables precise field-oriented control using only the motor’s Hall sensors. The overall sys- tem therefore requires no separate encoder, without compro- mising dynamics, torque control, or process stability. The design is also simplified because display control is integrated into the controller electronics. This eliminates additional components, reducing space requirements and complexity while keeping the tool compact, robust, and cost-optimized
despite its expanded functionality. Decisions like these are not made in isolation. They are the result of close collabora- tion between the development teams at both companies. “The collaboration is very straightforward,” says Andreas Keller. “We are geographically close, speak the same lan- guage, and can discuss technical questions directly. That makes many things easier.” For maxon, the project is also interesting because it brings together several areas of expertise. In addition to the motor, the motion control platform also comes from maxon. Spe- cialists from various disciplines supported the development over many years. Today, Kim Zimmermann coordinates the collaboration between Signode and the maxon sites and com- petence centers involved. The next stage of evolution The collaboration between Signode and maxon extends across several generations of tools. maxon motors were used in the hand strapping tools from an early stage. Another important step came later with the switch to brushless drives. The BXT4 now represents the next stage of evolution – shaped by the close interplay between mechanics and motion control. For the operator, all this technology remains largely invis- ible. They insert the strap, pull the trigger, and the tool han- dles the rest reliably and precisely.
Developed together
Signode — Overall mechanical concept — Ergonomics and operating concept — Tool and product development — Integration of all components
maxon — EC-i motor
— ESCON2 servo controller — Firmware and drive control — Motion control expertise — Packaging Technology Studio as a service tool The result: an overall system in which mechanics, drive, electronics, and application were coordinated from the outset.
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Motion Control
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