Don't know what website you went to for Brother, but I went in and typed in her model number and the question popped up as a FAQ---they say that if you are a moderate user (2-3 hours per day) it should be cleaned and oiled by an authorized Brother dealer every 500 hours. I you are a heavy user, with constant high speeds or more than 3 hours per day, then it should be cleaned and oiled every 300 hours. I would think if it is running ok, then once a year would be suffecient. Just google Brother Sewing Machines and you will see under Contact us