These hoes is for fixing vertical frames at bottom frame with screws. Building a top frame to the sail is performed as shown in the following figure. Prepare five bolts with ring for top level bridle connection, two wing nuts and three nuts. Each bolt sizes are 3mm diameter and its length is 15mm. Bolts should be secured with proper adhessive so as not to rotate when build frames with wing nut.
Ring provided on the top of bolt is for stainless small ring to which a bridle is binded.
Building a bottom frame to the sail is similar to building a top frame. Prepare ordinary five bolts which length is 15mm and diameter is 3mm. At a bottom frame, bolt with ring is not used because no bridle is secured to the bottom frame. Prepare five wing nuts. These wing nuts are used to fix a center frame, both sides frames and diagonal frames to the bottom frame.