Repair: Clunking Overlocker
My trusty Toyota overlocker started to make a horrible clunking noise recently, and was missing stitches. It almost seemed like the tension settings were wrong (but I knew they weren’t) and the nasty clunking and clicking told me that all was not well with the machine. I decided to see if I could find the source of the problem myself, without having to pay to have my machine serviced.
It turned out that the source of the problem was in the mechanism beneath the footplate of the machine. When the machine needle passes beneath the footplate, it creates a loop of thread that gets pulled back up when the needle returns. A hook-like arm feeds more cotton through the loop of thread before the needle returns, and the timing of this arm is controlled by a machine screw with an Allen head. In my machine, the hook-arm had slipped, causing the hook to hit part of the machine and miss-thread the needle.
To fix the problem, I slackened off the Allen screw and advanced the machine slightly by hand. With the screw slack, the hook arm was disconnected from the rest of the machine. I tightened the screw, and tested the result by advancing the machine manually for a few stitches. I had to slacken and tighten the screw several times, advancing and reversing the machine by hand until I was satisfied that the hooking mechanism was aligned and working properly.
I made sure that the screw was tight, plugged the machine into the mains, and gave it a final test under power. The result was 100% successful, so I took the opportunity to clean the machine with a stiff paint brush, and applied some silicone oil to the mechanism under the foot.