Hello!
My father and I took up leather work as a hobby (small wallets and other knickknacks), and I recently purchased for us a Singer 111W155.
It's in great condition, sold by a couple that maintained it and ever had a professional fix up done on it. I purchased it complete, with the table, motor, pedal, whole nine yards.
So long story short, when I sat down to try and do some work with it, I noticed the tension was off. Mostly the problem is that the bobbin (yellow thread) seems to have too much tension as the needle thread (black thread) keeps poking through on the bobbin side, and the bobbin thread lays flat. I've been adjusting tension for a good two days now haha. It's gotten to the point where my best result are when I have the needle tension to it's maximum and the bobbin tension to the point where the screw is on the verge of falling out.
All this said, I also get the weird occurrence where the thread seems to be pulled through on both side! The stitch right above my finger in the photos is the same stitch from both sides of the material, as you can see, sometimes the bobbin (yellow) is pulled through on the needle side, and sometimes the needle (black) is pulled through on the bobbin side, all in the same stitch! This left me really confused!
I'm at my wits ends. I've checked that I have the correct thread and needle for the work I'm doing, I've checked that my thread is threaded throughout the machine correctly, I carefully wind the bobbin every time as to rule a malfunction out on that end.
Only thing I can think of is I have something adjusted wrong outside the tension adjustments? Is there something else that could be causing this problem?
Also, I'm not using the motor, I'm using the machine by hand by spinning the pulley (I was hoping on adding a handle and making this hand cranked), could it be that without the motor the tension is fundamentally being messed up?
Does it need to have the torque of the machine? I assumed not, but I could be assuming wrong.
I'm sorry if I'm not explaining this correctly, I really am new at this, furthermore I never thought I would be working with/interested in sewing machine until now haha.