There are a number of ways you can recycle your old sewing machine, from local recycling centres, returning it to the retailer you bought it from, and even through household recycling collection schemes.
Take your device to your local recycling centre, you can easily locate your nearest centre on the Recycle Now website.
Under the terms of the WEEE directive, all retailers must provide a way for customers to dispose of their old electrical items when they sell them a new version of the same item, either through a collection service or store take-back scheme. Check with your retailer for more details.
Some councils offer a household recycling collection service for small electrical devices. Contact your local authority for more details.