The Yarn Maker is a special tool in Harvest Moon: Friends of Mineral Town and Harvest Moon: More Friends of Mineral Town. In order to get the yarn maker, you must upgrade your animal barn in order to make room. After you get access to the Winter Mine, you can mine up Adamantite and give the ore and pay a fee of 20,000G to Saibara. Once it's built, you can put any quality wool into it to produce a ball of yarn of the same quality.