The machine achieves a longer distance from machine arm to needle by adopting a high & long arm. This means the machine dramatically increases workability when sewing large products such as sofas and car seats. The thread trimmer achieves consistent thread trimming regardless of thickness of the thread, i.e., from thin to thick thread. The machine has adopted the rotary thread trimming mechanism which matches, in particular, design stitch with thick thread for furniture and bags. The automatic thread trimmer improves workability and increases productivity. When compared with the sewing machine without a thread trimmer, the DU-1281-7 substantially decreases the consumption of thread. The knife pressure can be adjusted with the adjusting screw.