Big rush order to get out. 14 pairs of skidboots I'd promised (against my better judgement) to a long-time customer.
I'm stitching along, get distracted momentarily and I'm almost over the edge of the seamline. Yank my foot off the pedal and grab the handwheel to stop the needle. There's a jerk, a thump and a big freakin' bird's nest. Shoot.
Pull the ruined boot out, clean out the tangle and stick a piece of scrap neoprene in there to check the stitching. And it ain't pretty.
Change the needle, check the thread path, try again. No joy.
Okay, so, big ugly loopy stitching. Tension, obviously. Twiddle the tension screw. No change. None. Twiddle it some more. Nothing. Crank it all the way in with no visible effect on the stitching.
Hmm. Maybe the bobbin tension got borked somehow. Get the manual out. Discover that the bobbin tension is really not meant to be fiddled with. You have to take things apart to get to it.
Stand up, pace around, glare at the machine. Read the manual again. Open the machine up to take a look at what I'd actually have to do. Close it back up. Pick up the screwdriver. Put it back down.
Sit down, chew on the pad of my thumb and ponder.
Go back over the list of what's already been tried. Thread path. I'd checked it, yes, but...
So I pulled the thread out and re-threaded the machine. And there it was. The thread had followed the correct path but the jolt had pulled it loose from between the tension disks. No wonder adjusting the tension hadn't done any good.