I'm new to machine sewing and everything seems daunting. Stitch length, stitching styles, presser feet, materials etc.
I was going to practice a bit each day to get my technique up to speed before tackling a real job.
The first hill to climb was getting enough thread together to fill a couple of bobbins and have some left for the top stitch.
After I went through a few spools of quality polyester thread I decided to give the offshore ( Chinese) materials try.
I purchased a trail kit of 24 different colors and started my practice sessions by hemming pants and sewing T shirts.
That's when I started having ball up and dropped stitches. .
I took my machine into my local repair shop and they fine tuned it for me and I started again
Same problem. I checked everything.
Bobbins, tension, presser feet.
Nothing helped. Worse was the fact that my problems were sporadic and I couldn't pin down the cause (s).
On closer inspection I found the Chinese thread ( bottom spool) was a good deal coarser than the Guttermen brand I have been using. There were also little tufts of loose material all along the body of the thread.
This was my eureka moment and I grabbed my needle stash and slipped in an 18 gauge on the machine and bingo! The problem vanished!
I have yet to tune down to the minimum size bore on the needles but right now the thread slips through the needle without binding and lets me lay down a thread pattern easily.