flyingavocado
Member
So here is an interesting thing I learned today, which I think is worthy of knowledge sharing.
I finished scratch building a new Tiny Trainer, and then painted the fuselage of my DTFB (Black foam board) a couple nights ago. I had the unfortunate experience of the foam melting from the paint solvents. In part I attribute this issue to having used the all-black DTFB as it takes a lot more paint to cover, and also in part to me getting a little hasty trying to finish painting in a humid environment. Nevertheless, I went and maidened it the next afternoon, and to my delight it flew quite well and needed only a bump or two of trim.
This afternoon I went to fly it again, and when I did my pre-flight check I immediately noticed that the elevator deflection was very limited. I took the wing off and looked it over and what I discovered was the servo was wiggling around during the control inputs. The paper it to which it was glued had actually delaminated. I made the wise (but sad) decision not to fly it, and instead took it home.
This is where things get interesting. I just finished an attempt to salvage the fuselage of my new Tiny Trainer. As it turns out, because I only painted the top side of the elevator and the foam melted/paper shrunk, it warped the elevator and seems to have continued to warp as the paint continue to dry over the next 24 hours. Since the elevator warped, the warped surface had a very large amount of tension on the control surface - to the point where moving even moving it by hand was taut. The warp in the foam acted like a spring, which added resistance in both directions. I believe this in turn caused so much force on the servo, when it moved around it ended up delaminating the paper to which it was glued.
I hope this helps someone out there, I know it has been enlightening for me.
I finished scratch building a new Tiny Trainer, and then painted the fuselage of my DTFB (Black foam board) a couple nights ago. I had the unfortunate experience of the foam melting from the paint solvents. In part I attribute this issue to having used the all-black DTFB as it takes a lot more paint to cover, and also in part to me getting a little hasty trying to finish painting in a humid environment. Nevertheless, I went and maidened it the next afternoon, and to my delight it flew quite well and needed only a bump or two of trim.
This afternoon I went to fly it again, and when I did my pre-flight check I immediately noticed that the elevator deflection was very limited. I took the wing off and looked it over and what I discovered was the servo was wiggling around during the control inputs. The paper it to which it was glued had actually delaminated. I made the wise (but sad) decision not to fly it, and instead took it home.
This is where things get interesting. I just finished an attempt to salvage the fuselage of my new Tiny Trainer. As it turns out, because I only painted the top side of the elevator and the foam melted/paper shrunk, it warped the elevator and seems to have continued to warp as the paint continue to dry over the next 24 hours. Since the elevator warped, the warped surface had a very large amount of tension on the control surface - to the point where moving even moving it by hand was taut. The warp in the foam acted like a spring, which added resistance in both directions. I believe this in turn caused so much force on the servo, when it moved around it ended up delaminating the paper to which it was glued.
I hope this helps someone out there, I know it has been enlightening for me.