there is so much controversy about this...i am so surprised...the wick and any metal to metal contact should be oiled...it cannot hurt...there is lightweight machine oil out there...do not use a gun oil or hardware store brand as it is too thick...i oil my wick & the shaft of my presser foot every 5 bobbins...i have a 6600 also and am surprised at how dusty the bobbin case becomes...i now have a system where i wind 5 bobbins at a time...when i run out of them, i stop, take the machine apart & clean...i find that cheap watercolor brushes from the dollar store are great for getting into the crevices under & around the bobbin case...plus, being plastic they dont break off any pieces which may fall into the enclosed area...when they get out of shape, just toss them...they are cheap enuf...dont use any canned air...it contains moisture...its best to get out as much lint as possible...then oil the wick and sew for a few lines onto some scrap fabric...even the area where the lightbulb is should get dusted once in a while....monica in tx with her 4th janome...(i like my 7500 better than the 6600)...its a little 'fussy'...