The winglets were purchased from David Colling. They are constructed of carbon fiber. Wayne Paul mounted the inline skate wheels. The winglet end ribs were formed using 3/4 inch plywood and were glued in place using MGS epoxy resin. Aileron counter balance were removed by the builder. Foam was used as tip-plate spacers.
I purchased eight shoulder bolts with a socket head. The dimensions where 1/4" shoulder and 1/8" depth. I then made two aluminum plates for each wing tip. (I used 1/8 in thick 6061-T6; however, would recommend using 2024-T3.) One set of plates are screwed to the wings and the other set to the winglets. After aligning each wingtip/winglet plate set they were fastened together and four small diameter holes drilled through both plates. Then the winglet plate was tapped out to the 3/16th shoulder bolt threads. Thin AN washers were used as shoulder bolt spacers. The washer allows the to plate to not have to be perfectly flat.
The Plate that attaches to the wing was then drilled out to the 1/4 Diameter of the shoulder. Approximately a 1/2" in front of the 1/4 inch hole I drilled a 3/8" hole, large enough for the head of the bolt to fit though. All these holes were aligned up using a mill but with some care it could be down by hand. I then cut a 1/4 inch slot between the 1/4" holes and the 3/8" holes. Now the two plate lock together. (The slots on the wing side look like the slot you see on the back of picture frame.) I then routed out the foam inside of the aluminum plate on the wing side so that the head would fit inside.
To install I take the winglet, insert the heads of the bolts into the slots on wingtip plate, and with a firm push aft the bolts engage into the slots. A piece of wing tape around the gap between the winglet and the wing and it is ready to fly. (I have tested it up to 150MPH and flown every day for a week at Region 8 contest without removing the tape and all seems to stay securely in place.)
To remove I remove the tape firmly push the winglet forward and pull outward to remove the tip. I built an additional set of slotted plates and mounted them in my trailer so I just mount the tips in the trailer for storage. (See the picture below.)
(Photos by Wayne Paul)