I have an old Kenmore, 158.13041, I think from the 60's, it still has a little sticker on the motor that says 1-3 drops of oil every 6 months (at the red dots) which are 1 on each side of motor, so 2 places. I would think it matters though how much you sew, but I do it at least that often. It is in a cabinet, very very heavy, but I also lean it back and dab oil on some of the moving parts underneath. Had it serviced when we lived in Florida, and believe it or not, this company made house calls, so I watched everything he did, so I know pretty much the most important areas.