This video shows this machine in operation sewing the straight stitch and reverse (back tack) for tying off your stitches. Shows you how to thread this machine, change the stitch length, find the light switch, shows the potted motor, etc. This machine is currently for sale in my ETSY shop. https://www.etsy.com/your/shops/Castl...
The SINGER 15-91 is a rod driven machine-there is no belt.