Here is a tip from my sewing machine repairman son: Wind 3 bobbins. After using up all 3 bobbins, clean your machine and replace your needle. I know replacing the needle this often sounds insane but it really needs it as it goes thru the material 100's of thousands of time during the time it takes to use up 3 bobbins. To clean, turn off the machine first. He recommends an inexpensive child's water color paint brush, the kind you find at the dollar store. The lint will stick to it and it has good reach. Remove the top plate to get at all the parts you can see. Oil, with any approved oil for sewing machines, the bobbin area lightly every time you clean. He does not recommend the compressed air. Once your machine plate is put back in place, sew through a piece of scrap fabric to remove any excess oil. The lint may be removed from the brush by flicking it across your hand over the trash can. It is easy to lose track of when you cleaned last, so the 3 bobbins works as a reminder. It will keep your machine running smoother longer and lower your frustration level with a poorly running machine. He also highly recommends having it proffesionaly serviced once a year but no less than every other year if you perform good cleaning yourself. Happy Sewing!