If you can get your hands on an old heavy gauge wire coat hanger, the ones you used to get from the dry cleaners you can make your own bobbin cradle, I made mine by winding the wire round the post 3 times then after deciding how long I wanted the holder to be from the vice head bent the wire at a right angle up to where it was level with the vice head, I then formed the cradle by bending the wire to form a U bend with a pair of pliers, after forming the bend I covered it with shrink tubing to leave a smooth surface for the silk to rest on. It works for me.