|Innards on the outside|
They are complicated things these sewing machines...
Here's the project in progress (if anyone is wondering, it will be the logo of the 12th Mechanized Brigade - our volunteer is also in the army). I was using Heirloom stitch which is a very thick stitch involving a lot of needle movement - but I don't think this should cause a problem.
I tried to do some minor adjustments before taking the side off - they just led to three sad and broken needles. With some trial and error, I managed to solve part of the problem but the knocking was still there.
Unfortunately, our first aid failed to fully identify the problem so, while I did get an interesting look inside my machine, I am going to have to take her to be serviced.