The BERNINA 880 manual describes two different ways to guide thread that is lively, metallic, loosely twisted, or prone to uneven release. They are model-specific options, not a universal metallic-thread setup. Confirm the manual for your exact B880 and choose the path that matches the thread and included hardware.
Eyelet unit and lubricator#
The Thread-Guide-and-Lubricating Unit can be used without its lubricator as an eyelet that guides lively thread toward the pretensioner. With the lubricator installed, BERNINA recommends it for examples such as metallic or loosely twisted thread. The manual says silicone fluid is only for lubricating thread; never use it on the hook system. Depending on the thread, upper tension may need a slight reduction, but no amount is specified. Test a sample rather than transferring a dial value.
Radial thread guide#
The separate Radial Thread Guide is intended to make release more consistent for metallic, lively, or evenly wound spools. BERNINA prefers the rear spool pin and a rotary disc with a white plastic inner part there; the manual says not to use the bobbin-winder pin. For initial threading with this route, pull an extra inch of thread from the spool before using the threader. A slight upper-tension reduction may be needed depending on the thread.
The manual also describes a separate B880 lower-thread lug and tool, but does not say how to choose among its listed starting positions. That is not a feed-aid adjustment recipe. For general thread-path checks, see the rethread-and-test guide.