Operation
Operating Instructions 581 - 01.0 - 05/201632
Threading the gimp thread: Subclass 141 and 341
Fig. 19: Threading the gimp thread: Subclass 141 and 341 (1)
Fig. 20: Threading the gimp thread: Subclass 141 and 341 (2)
3. Sew the buttonhole and check whether the gimp is pulled back 
far enough. 
If necessary, rethread the gimp thread as shown in B.
(1) - Gimp thread