Singer 306 Hook Swap

Step one in preparing my test bed clunker to be my daily driver for the foreseeable future. The heart of a rotary hook machine is the hook assembly. I've used this machine to experiment with different hook and bobbin combinations. For long term heavy use I've decided on a new 96-10 industrial hook mated to a slightly modified 20U shuttle. I had already been using the shuttle to allow running 20U open top bobbin cases and generic L class bobbins. The stock 306 is known to be sensitive about the bobbins used and many of them require a bobbin case with an index notch at the five o'clock position. This modification resolves both issues and allows the use of standard 15 x 1 needles while set to the stock timing and without any permanent alterations to the machine.