There's a lot of response here and I haven't read to the end. Adding my comment though. I don't cover mine. If my Janome gets dusty, I wipe it off. Have had it a lot of years and it's doing well--but then I use it several times a week. As to oiling--be sure you read the instructions with your machine. Most computerized machines do not need oiling and you may create a problem doing that! The older machines that had moving mechanisms did require that maintenance but not so nowadays. When I clean mine, I do put machine oil on a Qtip to aid in collecting the extra lint, etc and I do swipe it around the inside of the bobbin case but that's all. No real oiling as we used to do. I suppose one reason I don't cover my machine--the piano tuner recommended not covering the keys of the piano because it's better that the air circulate through the instrument. Perhaps a cloth cover is better than the hard plastic one that may have been included with your machine?? The hard plastic one will protect it if the machine is being transported but we don't want to trap moisture inside when it's at home and idle.