Mass bunching of thread in the bobbin compartment

Check your stitch sample. Dollars to donuts it's the top thread bird nesting (also called thread nesting) under the fabric. Issues appearing under the fabric is usually top thread related. Problems appearing on the top of the fabric is usually bobbin thread related.

Remove the top thread from your machine.
Be sure to start with a brand new needle.
ALWAYS RAISE the presser foot and rethread the top.

...

Barbara,
Upper thread looping around the shuttle is typically caused by improper threading through the upper tension disks and takeup lever. Check the instruction manual, carefully rethread the top of your machine and make sure the presser foot is in the down position. If the problem continues it may indicate an issue with tension disks. Remove the upper thread, fold a clean piece of fabric and with the presser foot raised to open the tension disks, place the fabric it in the thread path, through the upper tension disks. Lower the presser foot and draw the fabric back and forth to clean any build up of grime and wax from the disks. Lift the presser foot, remove the fabric, rethread and try again.

If the problem persists, you should not need any tools to remove the shuttle to inspect it - sometimes it is necessary to remove the needle plate to lift it out. Check the edges and underside of the plastic shuttle for marks caused by needle strikes - these can catch the thread causing the issue you describe. If there are marks, you may be able to polish them out with fine (600 grit or higher) wet and dry paper. I generally replace them. Also check the tip of the hook for marks - you can often feel these with your fingernail. If they are present, you may need to get a mechanic to polish them out.

Has to be pushed in to wind the bobbin.

It's like one of those peg boards you have to turn your bobbin case round and round until it fits. It should click right in unless you have the wrong size bobbin

Look in your book.

- There is a bobbin (clear plastic) it rotates.
- The bobbin fits into the bobbin case (black), it does not rotate.
- The bobbin case is nested into the shuttle which does rotate.

There is no bobbin shuttle.

indicates a needle /hook timing problem
check for loose needle

The bobbin case is not in the shuttle.

Raise the needle to it's highest position.

Lift the lever on the back of the bobbin case and hold it open as you insert the case into the shuttle; arm on the case pointing up. You may have to turn a bit to the left or right - it will click when in place.

Hi. I have a CS-8060 and while I love the machine--the bobbin winder isn't my favorite. Anyway, I have found that the cover to the bobbin winder must be opened completely, also the thread spool must be as far back as possible. Another place I'd check is with a small flashlight just under the small bobbin spool. It can be hard to see under there, so a small flashlight helps. I have gotten thread wound around the pin that goes up to hold the bobbin and if sufficient thread has gotten up in there it could keep the spool from spinning. It's hard to clean out, but careful use of a seam ripper and tweezers does the job.

Good luck and let me know if this works.

Robbie

no idea... did you lock thread onto bobbin so it holds to wind?

I do have the very same problem! I took my bobbin case out and took a good look at it, turns out right below the plastic hook part, the plastic was cracked off (probably due to thread jamming). Turns out I need a new internal bobbin case, which range in price from $35-$50 from what I researched. I had no luck with local sewing centers on finding the part.
That may (or not) be your issue as well. Good luck, and I hope this your issue is simple fix. A little tune up after might be needed, HAPPY SEWING!! ~Kelly J~