The Upholstery Forum

Hello, I'm having an issue with my Pfaff 1222 sewing machine. There's a grinding noise at the needle (1st video), when the top thread is pulled through the fabric. As you can see on the 2nd video the noise disappears when the machine is unthreaded.

Here's what I tested :
- replacing the needle
- threading the machine with a different thread
- playing with bobbin and needle thread tensions
- sewing different fabrics
- oiling the hook race
- doing the feed timing procedure as per the technical manual
- checking the hook timing as per the technical manual
- adjusting the position of the finger that stops the bobbin case as per the technical manual

I'm also noticing some stitch inconsistence, I don't know if it's linked or not.
Here are some videos and pictures of the area of interest. https://imgur.com/gallery/pmvHPDV

Audio was pretty poor on my end on all videos but clearly the loop passing around the bobbin is causing the noise and poor stitching as you said it goes away without top thread. Was there a jam or anything that preceded this issue?

No, nothing happent before ..