Brother VX Series Sewing Machine Service Manual. Model numbers covered by this manual are VX511, VX541, VX561, VX581 (Free arm sewing machine) VX611, VX641, VX661, VX681 VX710, VX720, VX740, VX760, VX780 VX516, VX546, VX566, VX586 (Flat bed sewing machine) VX616, VX646, VX666, VX686 Examples include: * Troubles and check points. * Sewing timing of the needle. * Setting of maximum stitch width. * Setting of upper thread tension dial. * Adjusting of the drive belts. * Much more.