28 n MACHINE BUILDING April 2026 www.drivesncontrols.com Screw monitoring system cuts reworks for blind-maker The German machine-builder Soga Gallenbach develops special machines for fixture assemblies and 3D printing, as well as selling pneumatic components. Its customers come from industries including medical technology and aerospace engineering. “These industries have an especially high demand for precision,” reports the company’s managing director, Fabian Gallenbach. He trained at a Swiss watch manufacturer, where he learned to cut a micrometre in half. When founding Soga, his goal was to use the precision he had learned to build machines. Gallenbach finds that customers are becoming increasingly demanding. “We hardly ever get simple requests anymore,” he notes. “We offer our customers special developments they can use in production immediately after delivery.” One such customer is the Bavarian sun blind manufacturer, Roma, which asked Soga to supply a multiple screwing system for joining profile rails. Previously, it had been using an automated screwing system with screw feed drilling, which could screw up to three aluminium or plastic profile rails together. But it didn’t include any monitoring functions. “The drill screw frequently created chips between the screw head and profile rail,” Gallenbach explains, “especially with wrought aluminium alloys”. A visible cap is placed on top of the screw, but because of the chips, the cap could not be attached properly. Roma’s staff repeatedly had to rework pieces by hand, and the company wanted to avoid this in future. Roma wanted a machine that would also pre-drill profile rails from 710–5,710mm long. “Over the past 15 years, we have developed more than 50 screwing units with torques from 0.4–200Nm,” Gallenbach reports. “As a result, we make it possible for our customers to mount screws without needing workers to manually retighten or perform reworks.” Soga developed a screwing system that was able to monitor different screwing depths and tightening torques. “We developed a strategy specifically for plastic screw connections in which our pneumatic screwdriver operates with pressure pulses,” Gallenbach explains. Plastic does not need the final torque to be higher during the final tightening process than at any other point. This means that it has to be sensitive. The system feeds the screws automatically and then screws them in pneumatically. It is equipped with five mounting heads that move independently in the X direction on a gear rack. Each head has a Z-axis and a drilling axis. For the X-axis, the German motion engineering specialist Stober supplied its ZVPE rack-and-pinion gearboxes as well as EZ synchronous servomotors. For the Z-axis, Soga is using EZ motors with a spindle drive. To make sure that the five heads do not collide with each other on the gear rack, Stober engineers implemented a triple collision protection strategy: the controller monitors the head positions relative to each other; software limit switches have been parameterised with the permitted travel range for each X-axis; and a mechanical safety switch is also located on each head. The engineers equipped the system with two drawers for loading the profile rails. The machine can supply profiles for processing either separately or synchronously. The components are inserted and clamped by hand. The drawers move using two Y-axes that operate automatically. Each drawer uses a Stober PE planetary gearbox with a beltand-spindle drive, combined with an EZ synchronous servomotor. A German manufacturer of sun blinds has cut the amount of reworking it needs to do by introducing a machine that screws profile rails together using multiple heads that monitor both the screw depth and the tightening torque. The screwing system in Roma’s machine monitors different screwing depths and tightening torques
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