RC BLog: Pretorian 435: PowerlineHobbies-Green RC Models Tiny Sopwith

Tuesday, August 23, 2011

PowerlineHobbies-Green RC Models Tiny Sopwith

Last night I put the Green RC Tiny Sopwith together. I had expected this to be a "bolt the wheels on, install the receiver and be done with it" build, but the scale control surface "ropes" were a challenge, and in figuring it out I screwed it up. I managed to solve the problems I created and solved other problems in doing so, but she exhausted me.

In general she is a thing of beauty, hands down my most beautiful airplane for all her scale parts. She is quite small, and since her wing does not detach once installed, getting to the innards proved very challenging. God forbid I should ever have to change a servo... they are buried inside and I am not sure how I would get to them. I don't know why they made to wing a permanent attachment. The underside wing bolt suggests it isn't but I could remove that bolt and nothing would change. That wing isn't going anywhere...

They used string for the control rods to keep things scale. I wish they had used the same plastic coated rove wire they used for the guy wires... The design requires string attached to tiny springs attached to snap hooks which then attache to balsa control horns (yes, I broke one trying to get the snap hook off). The string was just a touch short for me when I tried to weave the string through the spring and snap hook as shown in the video build manual, and then it wasn't snug enough. I could also tell getting the pull-pull system snug was going to be next to impossible. I ended up with too much play in the rudder and too little string. I ended up replacing the string in the rudder pull-pull system with floral wire, into which I did manage to incorporate the spring. Snug, balanced and effective! In the photo above you can see the string as I fished the wire through. The snap hooks inside the fuse connected to the servos were buried inside. I used the string to pull it up, attached the wire, and pulled the wire back down, then cut the string. In doing this I accidentally pulled one of the elevator strings out... acutally all of them... and ended up having to use the wire to fish the strings back through. I didn't want to spend hours trying to set the whole thing up with wires... In the end I used double half-hitch sliding knots on the string for the elevators and was able to get everything balanced, centered and snug, then CA'd the knots and string to secure it in place. Works great! No spring on the elevator, though, which is good, as I lost one somehow.