My Pfaff Varimatic 6091 (aka Pfaff Stretch and Jeans) had the needle slightly off centre for a long time. This had not been an issue until I tried to sew in an invisible zipper, using a special invisible zipper foot, into a lace skirt. That was a nightmare. On one side the zip would be stitched too far from the edge, which was actually not a problem, even better because the runner didn't catch the embroidery of the lace. But on the other side the stitches would go almost through the spiral, which of course blocked the movement of the runner completely. After undoing and redoing it three times, I decided that the time has come for the needle to be centred properly. After at least an hour of research, I found this manual for Pfaff Tiptronic 2010-2040, where on pages 32-33 there are instructions on how to adjust position of the needle in the needle plate, and the pictures (Fig. 28, page 33) looked like what I saw inside my machine:
The manual is in Russian: to adjust the position of the needle, screws 45 have to be loosened and the plate 46 then can be moved - this will move the needle. Once the needle is centred, screws 45 have to be tightened. And voila!
I must add that at the end I did not use the invisible zipper foot to sew in the zipper into my skirt. Even with the needle in the right position, the stitch line was too close to the spiral, and the runner, even though it could move, kept catching and pulling the embroidery thread of the lace. So I sewn in the zipper the usual way, as shown, for example, here.
The manual is in Russian: to adjust the position of the needle, screws 45 have to be loosened and the plate 46 then can be moved - this will move the needle. Once the needle is centred, screws 45 have to be tightened. And voila!
I must add that at the end I did not use the invisible zipper foot to sew in the zipper into my skirt. Even with the needle in the right position, the stitch line was too close to the spiral, and the runner, even though it could move, kept catching and pulling the embroidery thread of the lace. So I sewn in the zipper the usual way, as shown, for example, here.