Zhang San Feng 13 Dynamic Form - Charles Cashell video Added: Jan 2020 | Last update: Mar 2020 Charles Cashell performs the Zhang San Feng 13 Dynamic Form. Presented at the 2017 Washington Taiji Festival at the Cabin John Tai Chi Court in Bethesda, Maryland. Tags: Zhang San Feng 13 Washington Tai Chi Festival Charles Cashell Washington Taiji Festival