My sewing machine has once again bewildered me, and I'm hoping someone with a blackbelt in Kenmore can explain what happened please :-)
I pulled my trusty machine out of mothballs about a month ago to start making/stockpiling drawstring skirts and other straight-seam super-simple stuff. And then I got bit by a (non-SCA!) craft-y bug, and launched into learning to make Lakota Star Quilts (see www.nativeamericanstarquilts.com for WAY cool pictures). So my sewing machine has had more mileage in the last month than probably the previous two years combined. Which may or may not have anything to do with what just happened.
In the middle of a plain straight seam, the bobbin thread jammed up. Not terribly irregular. But it kept jamming. I disassembled the bobbin assembly, and brushed out all the lint. Kept jamming. I disassembled the plate over the feed dogs and brushed all THAT out. Kept jamming. Ran it with the hand-wheel, keeping the bobbin compartment open, and could SEE the thread getting caught on the lever of the bobbin cartridge (it's a vertical metal bobbin-holder, and the lever is the bit that lets me keep the bobbin IN it as I load it into the compartment). Cleaned EVERYthing again. Kept jamming. I left it alone for two days. Kept jamming. I checked the internet - nothing specific enough to be useful. Resisted the temptation to throw it out a window.
Today, I cleaned everything AGAIN (kept jamming) and I was about to switch out the bobbin itself, wondering if somehow it's a millimeter too wide, and pushing the cartridge out a critically small depth. Remembered something I'd seen online where users recommended "Brush out the lint, oil the moving parts, yadda yadda, and change the needle." Remembered the Sherlock Holmes quote "Once you have eliminated the impossible, whatever is left - however imPROBable - must be the truth." Since I'd done everything else, I decided to change the needle. AND THE $*&@^%%!* THING QUIT JAMMING!!!
Now, I'm grateful to the powers that be that I can now resume my quilting. But the NT part of my INTP personality can't let go of "WHY?!" Can anyone with sewing machine experience explain to me why changing the needle fixed an issue with thread catching on the bobbin lever?
If it were a car, I'd say I've been having problems with the brakes grinding, and fixed it by changing the air filter. I know it's a complicated machine, but it's driving me bananas that I can't figure out the connection :-P
Any thoughts would be appreciated, and lower my blood pressure significantly :-)