Reading a very old post from 07, I found out I can drop the feed dogs on my 15! Wow! I am so excited, it free motions so nicely, only problem is my top thread keeps breaking and the spool messes up, like almost jumps off it post! I broke 6 needles today!!! I tried adjusting the tension both upper and lower, I know it is threaded correct, new needle (Ha) and diffrent thread! I am so excited about FM on this machine! Gee, I have only owned it 34 yrs now and just finding this out! If I could firgue out what the trouble is, I could really enjoy this! It has an inch longer throat than my other machines too!!! Please, any ideas!