Just got all of all four of my machines cleaned. I clean my quilter everytime I finish a quilt. The other three I clean about every three months, more if I have used them alot more than usual. I always feel so good after they are clean. When I got my first machine years ago, the kind little old man who sold it to me said if I would clean it every three months, it would last a lifetime (little did he know how much I would sew!) It only lasted about twenty years, until it was worn out. He sold me my next one and then retired. Since then I have bought the serger and the quilter and and embroidery machine. But I never forgot the advice he gave me about cleaning them. When I take them to the "new guy" for a check up, he always comments on how clean they are. How often do you clean your machines?