Trials and tribulations. Lack of foresight on my part.


I have the bottom wing temporarily bolted on.


I installed the rear bolts and hard points first. And about a day later decided I had really screwed up. That I had the perfect recipe for loss of aircraft the way I installed the nut plate in the fuse. Not enough to hold it in there.


The nut plates are 1/16" birch ply with 1/4" on top to receive the blind nuts. It is in the 1/16" ply plate that the problem lies. There is just not enough surface area to hold it in there in negative high g turns. It is flush with the bottom of the wing saddle. It is about 1.5" long by 2.5" wide.So there is a total of 5.5" by 1/16" of area epoxied to the inside of the birch inner doubler. on top of it I glued two 1/4" thick by roughly 1/2"sqaure peices of ply for the blind nuts to sink into. They don't have enough glue area with the fuse sides and none with the aft bulkead. I am afraid that just wont take the loads.


I intend to leave the 1/16" plate be, but the 1/4" pieces have to be removed. I will try a real hot xacto blade and see if I can cut the epoxy.


I will then replace them with a one piece 1/4" ply piece for the blind nuts. And epoxied to the sides and rear bulkhead. I will then pin it with two small screws through into the sides. I will use a pair of servo mounting screws through the fuse sides and into the 1/4"ply plate. Counter sunk through the balsa fuse sides There is then the 1/8"light ply and 1/16" birch ply fuse doublers that the screws will be in and then the 1/4" blind nut plate. My wordage here really sucks. I hope you get the meaning of what I am trying to do though.


Now the front 1/16" birch ply nut plate is done the same way but I used nearly the same size blind nut plate that will be pinned with servo screws. I think this fix will now hold and not pull out of the bottom of the plane.


I epoxied a 1/16" birch ply pate onto the trailing edge of the bottom on the bottom. the bolts then go through this.


For front bolt pass through plate I spent about a week thinking about it. I don't wont the plate pulling through the top of the wing.


My answer is a 1/8" birch plate (sort of a very flat U shape) epoxied to the 1/4" leading edge doubler, with a nice lip under it that the bolt pass through plate sits on, plus it is epoxied to the L.E. doubler. I think there is plenty of glue surface area here to hold solidly. I also epoxied a piece of 1/8" by 1/4" birch ply on it's side on top of the upper spar inside surface. The bolt pass through plate is the epoxied on top of this and the lip of the U shaped L.E. peice.


I think this will take the loads.


For sure feel free to jump in and correct me on this.


I am not to sure I have described things well, but here are some pics, so between them and my write up I hope you get the ideal. And if you think it is still lacking or if you think I over did it let me know please.


Ken