RE: adding flaps to an arf
Steph,
So you can understand what’s going on here. On a War Bird it is common to land with 45-50 degrees of flap. If you pop it down at full tilt hopefully your servo will stall. If it does not you will damage the flap system or the plane just from the amount or energy involved. This can be anything from breaking the epoxy free on one or more hinges ( most common) to the flap coming off the plane (never sean, but read about). So we slow to 60mph then feed in the flap to reduce the stress on the system. The most common form of initial failure is hinge loosening up on one side (breaking free of the bond), I usually fix that with a drop of CA.
So will the ply alone work? Yes. But…
- First I would screw a sheet metal screw into one side of the ply where I can rap something around it to remove it. Then cut all the sides as free as I can with a sharp x-acto. Then use the screw to pull it out of place. If that proves to be to difficult, there is something else attached to it behind it, I would repair all cuts with CA. and continue on.
- If it comes out install the balsa blocks and button it back up with CA.
- If it does not come out I would look for ways to support the hinge by more than just the ply. One of my favorite tricks is to install the hinge point right on the side of a rib. Then when the hinge is installed drill a hole in the ply to add epoxy to hold the hinge point to the rib. Then foam the area after that. I use two part boat foam, but the rattle can house insulation foam is cheaper and more structural.
Without the balsa you have to use epoxy to fix loose hinges which will cause a lot more work. an ounce of prevention here beats having to diddle with it for ever.
Joe