Singer 306K – Bobbin Carrier
A few weeks ago it became clear why I was having issues with Bobbin tension, even after fitting a new spring to the bobbin carrier. I lifted the carrier out of the machine to change thread, and a part of the carrier fell off. It was obviously fatigued across the area where the thread passes through the shell and under the tension spring, hence the variable tension problems.
Replacing the bobbin carrier with the same part number is impossible without importing it from overseas at great expense and postage costs. However the best alternative bobbin carrier for a 306K is the version for the Singer 20U industrial machine, and this is available in NZ for a very small cost and local postage.
When fitted, the machine works fine, and 15×1 needles still work as before, as well as the 206×13 and the DBx1 needles. And as a bonus, the spring adjustment screw from the damaged carrier was transferred to the 15K110 which was missing one!
I tried the 20u bobbin carrier in my new 319k, and it does not fit. There is a lot about this on the web, but the reason it won’t fit is the tiny locating pin inside the hook. This is at the 4 o’clock position. There is a slot in the 319k bobbin carrier to go over the pin, which is not there on the 20u bobbin carrier or the 306k bobbin carrier. The 20u and 306k bobbin carriers locate using pins in the hook that locate in the mouth of the bobbin carrier in the 12 o’clock position.