Hi Karl, if you're looking for a pulley to gather the string there are a few options. The HS-785HB servo comes with a pulley or you can use a gear motor with the 615468 pulley. Keep in mind these pulleys are drum-style pulleys not intended for timing belt. If you have a question about timing belts and pulleys please email us at tech@servocity.com
If you had received the version with standard v-wheels instead of mini v-wheels, see alternative instructions here: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE--g5x6PimZlo.html
Hi Vincent, do you have one of these kits you are trying to assemble? If you have questions or confusion, please feel free to contact our Tech Team directly and they would be glad to assist. tech@servocity.com
