Control Fitting page 1

Started July 20, 2004

The  first step in fitting the flap to the wing is to install the flap hinges to the rear wing spar. The center flap hinge and the aileron drive hinge locations are already fixed and cannot be changed at this point. That is because these two hinges bolt up in conjunction with the flap and aileron support frames that we have already bolted in place during wing assembly.

The rod end bearings were just slipped into the hinge tubes, but not riveted yet.  The parts that will eventually bolt to the flap spar have been attached to the rod end bearings with a bolt & nut.  

I must have done something right because my flap lined right up away with no problems. Once properly positioned, the flap hinge angles were clamped to the flap spar as shown below:

When I built my flaps and ailerons, I riveted on the gussets at that time. If I could do it again, I would probably leave the top ones off until this fitting is done. That's because having them in place made it difficult to clamp the hinges to the flap spar.  As you can see in the above picture, I had to use some fairly large clamps and a couple of blocks of wood to clamp the hinges to the flap spar.  Without the gussets, I could have used little 2" clamps.

With three hinges, it is possible to have one of them off enough to cause some binding if they are not properly aligned with each other.  I'm, proud to say that mine moves very smoothly up and down with no friction at all. YAHOOO!!!!

Now, the hinge locations were marked on the flap spar, the flap was removed and the using these marks the hinges were match drilled to the flap spar.  Plate nuts were then installed on the backside of the flap spar using the Eric Newton plate nut installation method.  Again, the gusstes were a major pain in the A$$ when trying to reach the rivets.  I ended up just using cherrymax pull rivets to rivet the nut plates to the flap spar.  These are there to keep the nutplate from spinning when you tighten or loosen the bolts so its not critical.

With the hinges bolted to the rear spar and the hinge angles bolted to the flap spar, the last bit of business in the hinge department is to drill and rivet the rod end bearings into the hinge permanently.

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