I have and use this machine--it is a workhorse--love it ! One thing I do before loading bobbin is do a slight twist of bobbin like to open it, then screw back to position and load the bobbin with thread. Yes, need to check for any loose threads or tidbits in bobbin area. i do oil that area quite frequently--just a drop of oil. Not all bobbins fit correct. I have tried many places, sometime some from Ebay that work just fine. Be sure to run your finger around edge of bobbin, checking for any nicks or chips. Think I paid that price for my machine about 10 years ago and sew on it almost every day. Like that it is metal, hubs takes it out to his workshop once or twice a year and cleans and oils it. Love my machine ! Good Luck with yours !