Back again with ANOTHER episode!
WING SUB ASSEMBLY
I have the HIGHEST respect for all those who administer a contest: CD's Judges, Recorders, compilers, EVERTBODY deserves kudos for the effort they put in for the flyers. However, I harbor FEAR of those ANIMALS that run pull test in the pits! Normal, even NICE and certainly HARD WORKING people, but they become 800 lb gorillas when it comes to pull testing MY airplane!
All seriousness aside, I want the bellcrank mounting to be strong and durable but I also want a place to hang on to the airplane when I am trying to pull test. As supplied the Oriental comes with a substantial 4" bellcrank with a large bolt - mounted to a single platform. I think it is imperative that the bellcrank bolt be supported with mounts above and below the bellcrank to keep it stable. Call this a throwback to building foam wings, but if you take the bellcrank mounts and put them OUTSIDE the wing, then you can also run them up against the fuselage sides. This in turn gives a place to HOLD ON to the airplane when you are dealing with "old lead bottom" in the pull test pit.
The supplied bolt was too short to do all of this so a new 6-32 x 3" bolt was substituted. Since the bellcrank was loose removed anyway, I went ahead and REVERSED the bellcrank so the pushrod arm is now pointing toward the inboard wing tip and the front line is now UP. Been doing this since the attending the "church of Reverend Al" (Rabe) back in the early 1970's. Old habits die hard. While I was at it I also moved the bolt over far enough to get the flap m& elevator pushrods a little closer to the center of the wing - for a more direct shot to the flaps.
While contemplating the 3:2 Elevator to flap ratios, I first went through the normal excercise mixing and matching outputs. The inexcapable conclusion is that when using the traditional daisy chain of bellcrank to flap horn to elevator horn, the elevator has to get sped up . Time for Plan B: I have always been fond of slower controls, so I sought to not speed-up the elevator, but slow down the flaps. The solution I choose was to use a SECOND pushrod from the bellcrank. The rod from the outer output of the bellcrank goes to the outermost hole on the elevator horn. The flap rod goes from the SECOND hole in the bellcrank to the outermost hole in the flap horn. Result: when the elevator moves 30 degrees the flaps move "only" 22 degrees - that's close enough to 3:2 for me! Added benefit the bearing loads especially at the flap horn and bellcrank outputs is roughly halfed. BTW I used a short piece of 1/4" dowell rod for the elevator rod, and OF COURSE the flap horns were bushed with brass tubing.
Flap Horn and Elevator Horn Bearings
This was a shortcoming of the kit - no bearings. I made some out of Plastruc tube; drilled to fit over the horn wire, sanded flat on one side, then slit with a #11 Xacto. The slit side is glued back together with plastic cement (optional) and the bearing epoxied to the wing (or stab as appropriate) then a swatch of cloth wrapped over the bearing to hold it tight and reinforce it.
Hinges
Struggled with this. I WANTED to use the CA hinges because I have found them to be very durable as well as very easy to install. Pinned hinges would move freer. Settled on keeping the CA hinges, but cut them in 1/2 width strips so they would not be so stiff. One reason I thought I could get away with this is because I used:
Hinge Seals
I used clear Monocote top and bottom to seal the hingelines. I consider this to be as important a step as using moving control surfaces in the first place. Some folks don't believe in sealed hingelines - they are wrong.
Note to Leester: tomorrow the ENGINE choice is revealed (whoo hoo!!!)
Note to Bill: the answer is in the single digits... so far!