My name is Don Limnios and my career in the sewing industry started in the early '80's working on the engineering staff of an industrial sewing machine manufacturer. I started in the US branch office and shortly thereafter transferred to the manufacturing facility in Japan. I stayed there for four years. After working in various technical divisions such as R&D and special projects development, I transferred back to the US office where I eventually became the manager of the technical division.
The mid-'90's, saw the sewing industry in the US moving offshore and sales of commercial machines domestically rapidly dwindled. I left the commercial sewing machine company and also at that time I added service and repair of home sewing machines and sergers.
Many sewing machine services are done by people who are deemed "handy" or by a husband and wife team who decide to open a fabric/sewing shop and their introduction to working on a sewing machine comes from the trainer at the sewing machine headquarters. To be fair, many of these individuals may do an adequate job and some may do quite well.
My entire professional career has been in the sewing industry. From working on sewing machine design to manufacturing machines to installing machines in factories and training factory staff to servicing single needle featherwieghts to servicing multi-needle embroidery machines. The difference is I know what a sewing machine is inside and out; I know what a sewing machine needs to do to form a stitch. I have taught sewing machine mechanics and stitch theory on three continents and have been actively doing this work for 30 years.