Singer 306 Bobbin Installation
Singer 306W bobbin installation is a bit of a chore. While many machines offer a slide plate providing bobbin access, this machine does not. To access the bobbin, the machine is tilted back as shown above. There is a latch on the right-hand side which supports the machine in this position. For someone with fat fingers, this method may be preferred to trying to install a bobbin and bobbin case beneath a slide plate.
The 306W uses a vertical bobbin which many quilters claim makes a finer stitch--especially free-arm quilting--since bobbin thread doesn't have to make a 90-degree turn before reaching fabric. It spools in a relatively straight line up to the work area.
You MUST--repeat MUST--use a Singer 206X13 needle. If any other needle could be used in this machine, Singer would have figured out how to do it years ago. Some of these machines have been "retimed" to use other needles but that proves unsatisfactory when doing anything but straight stitch.
It will accommodate twin needle sewing using a 306x1 needle. Good luck in finding one.