Fully automated threaded insert installation significantly improves high-volume fabrication of assemblies produced from aluminum, magnesium, and more. In addition to the superior strength, sealing capability, and customization that Fredserts offer, the ability to fully automate installation also reduces overall process time and cost.
Development of the fully-automated Fredsert installation process was achieved through the cooperation of General Dynamics, ERI America, R&E Automation, Kuka Robotics, Atlas Copco, Robot Vision Technologies, Miller Precision Industries, and Welker Engineered Products. This report was authored by Jason Deters, a process & technology development specialist for General Dynamics Land Systems in Sterling Heights, Mich.
Fredsert threaded inserts are designed by General Dynamics to deliver unparalleled strength, sealing capability, and design flexibility in the most challenging applications. Fredserts are unique in that they can be easily removed and replaced without drilling or rework - great for applications with limited access, or where field service is needed. Used by General Dynamics for over a decade, they’ve only recently been offered to the commercial market. Design and Manufacturing Engineers in Defense, Aerospace, Naval, and Heavy Equipment industries now have an alternative that overcomes limitations associated with traditional threaded inserts.
For low to medium volume applications, Fredserts are installed manually with a torque wrench, or semi-automated with an electric nutrunner. For production volumes, however, Fredsert installation can be fully automated - using either a CNC machine or a robot to deliver the necessary torque. This capability provides significant advantage over traditional inserts, which are difficult or impossible to fully automate due to the mechanical-clamping aspect of their installation.
The CNC installation method uses an adaptor similar to a tension / compression tap holder to pull Fredserts from a tray and install them into tapped holes at a specified torque value. The user machines a part as they do today - but after the holes are tapped, the CNC program pulls the adaptor from the tool magazine and proceeds to install Fredserts. This capability enables users to combine machining and insert installation in one setup, a significant step toward Lean Production. This level of process control also ensures consistent and accurate installation every time, since the location and installation are precisely controlled by the CNC program. Incorporating this process requires relatively little investment, because the most expensive component, the CNC machine, is already there to machine the part.
General Dynamics has also developed a robotic installation cell, consisting of a robotic arm with an electric nut-runner that picks Fredserts from a tray and installs them into tapped holes. Like the CNC installation process, robotic Fredsert installation provides the unique ability to fully automate installation of a heavy duty threaded insert. Guided by an on-board vision system, robotic installation ensures proper placement regardless of variation in the workpiece. This approach allows installation into multiple surfaces in a single setup; perfect for applications involving large, complex parts.
More details, along with video footage of the automated process, can be found at www.fredsert.com.