Using step motor in feed machenism and needle bar machenism, the minimum increment can reach 0.05m to realize perfect and stable stitches.
It is possible to set soft start speed through the panel for the front 5 stitches to prevent the thread breakage.
You can set the reinforcement stitches for the last several stitiches to prevent the thread off from the buttonhole.
Through the adjustment of tension of electromagnet tension disc, it is possible to meet the requirement of  different tension for the parallel part and bar tacking part of buttonhole.