I am a Bernina lover. I have the 200, 150 and 160. They are quality machines with all metal parts. It must need an adjustment if it is not working correctly or it could be a threading problem. Be sure you have it threaded properly and thread it with the presser foot up until you get to the needle. This assures the thread is in all the tension discs. This should be done on any machine. I would take an old Bernina any day over a new machine. I helped my niece, DIL, her mother and daughter find used Berninas after buying other machines that just did not hold up and always had issues. I would take it back and ask that it be working properly if you bought it from a store. It should have been oiled and serviced if from a store. I also have an elna, two older singers and 4 FW's. The only machine I love sewing on as much as my Berninas are the FWs. I cannot speak for the Juki...only for the quality of a Bernina.