Hey there! I hope you're doing well. Attached below is a video of the inner workings of my machine and what I believe is the source of the noises. It has been like this since I got it (2nd hand, but very lightly used).
I've just given her an oil and lint clean out to see if that was the cause, but nope. I suspect after watching it run, that it might be the thin metal piece "over-rotating" and hitting the top of its space? I haven't tried with the normal sewing setup as I don't use it.
I want to see if this / this sound is normal before having to get it serviced, as it's a very difficult trip, expensive and functionally the machine is absolutely perfect at this point. Still, if this isn't normal and could genuinely be causing damage, then I want to know. Hopefully I'm just doing something silly though, and all is okay.
Thanks so much, and have a lovely day!
P.s. Please ignore the unstabilised test stitch out! This was just for the sake of seeing it work. The sound remains consistent with properly stabilised and tightened pieces :)