I have 4 and a long arm, but I only use 2. My daughter uses another when she's home and needs to sew something. I have an acquaintance who has many machines. She has a large home and her children are grown so she has them set up around her house and sews wherever the mood strikes her. She keeps different projects going at different machines. I think that's clever, no need to clean up one thing when you want to work on another!