I also have the Brother PE770. It's a great little machine requiring little maintenance. After 3 years I had to have 1 part replaced. My repairman replaced the original plastic part with a metal Babylock part. Another 3 years has passed and it's still working great. The amount of thread required depends on the designs you are using. Doing redwork only does not require much thread. Solid designs require more, and that varies depending on the designer. Some designs are more dense than others.