For Christmas this past year I got the whiz bang idea to make everyone in my family a fleece hat with a matching neck gaiter. I made several sets for my quilt guild's bazaar too. All together I made about 36 sets. A lot of the sewing was done on my serger but some was done on my Janome 3160, which I bought with my serger (it was a 2-for deal!). The finishing of the hats was done by hand -- phew -- finished up at Christmas at my Mom's. All that sewing made my machine DIRTY!!!! So it was more than time to clean it out with my vacuum.
Just like replacing a dull rotary cutter blade makes cutting a breeze, cleaning out your feed dogs and bobbin case make your sewing machine work better -- so clean yours monthly if not more often!