I clean out the lint in my Bernina with every bobbin change and give it a drop of oil with every third bobbin change. That machine goes in for servicing once a year. My Featherweight gets serviced once a week since I sew on it every spare minute. There are so many places that need to be oiled on a Featherweight and gears and the motor that need grease occasionally. When I first started servicing the Featherweight, I really disliked all the work involved in servicing that machine. Now, the work goes quickly and I love how it sews when I service it weekly.