I was lucky to work with an ex industrial sewing machine maint. tech. I would bring him my machines and he would show me how to get the housing off and where to clean, where to oil, how to fix the clutch for the bobbin winder, and how to set the timing. I haven't had to use a machine repairman in years. I did let one shop order a new part for one of my machines and found out later when I cleaned it a used part was put in but I was charged for a new one. It makes me wonder how many repairs are made this way.