Prepped flap mechanism parts

September 25, 2015 – Using the parts I previously worked on for the flap mechanism, I clecoed everything together for drilling.

Here are all the covers screwed and clecoed in place.

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The left side cover has to be notched to clear the bolt for the flap motor. Here’s the rough cut before cleaning it up:


I drilled for nutplates where necessary:


Then it was time to deburr, prep and paint.


After everything dried, I started assembling some of the parts. Used the squeezer for almost everything.

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I’ll still install the flap motor, but I probably won’t install anything in the airplane until later.

Time: 5:30

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Started flap mechanism

September 16, 2015 – I started the flaps by installing the welded actuator assembly.

This assembly is fitted into the fuselage using three blocks to hold it in place. The outboard ones were previously drilled and ready to go. I just had to slide them on the ends and bolt the assembly in place. I used a little grease to get the welded tube started in the blocks, then it required a little finesse to get everything in, but I got it there.

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The center block still needed to be drilled and sawed in half. I did this per the drawing, but one of the bolt holes didn’t line up with the frame underneath the floor. I decided just to drill another hole in what should have been the correct location. Here’s the lower half of the block in place. You can see where the new hole is situated over the frame.


I used a drill bushing to drill through the structure, then took the holes up to size and fitted the block in place. I like this a lot better. I also trimmed the center tunnel cover so it fits around the block, allowing the cover to be removed without disturbing the block.

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The electric flap actuator needs to be drilled for safety wire, because it was possible for the actuator to unscrew itself and become inop. I had a drill bit somewhere in the neighborhood of a #54, and it worked just fine. I’ll safety it later.


Several brackets have to be made for the flap mechanism. I made those.


I fitted one of those brackets into the channel that holds the actuator. Only one of the holes was previously drilled, so I back-drilled the rest through the channel, and took the center hole up to 1/4″.


The 1/4″ hole in the channel gets enlarged to 5/8″ so the bolt head can sit in there.


The top of the channel is attached to the seat brace by a bent piece of angle. After cutting it out and bending it, I clamped it in place and drilled it.


Then it was time to temp install the actuator in the channel. Another angle needs to be drilled, but I needed to do that with everything in place. Here’s a view of the assembly, with the angle in place and drilled (under the nut).


The instructions say to get the actuator ready to install by running it out halfway. I hooked up the two wires to my power supply and saw which way it ran. The actuator came fully retracted. I extended it all the way and found that the full travel was 5 inches. So I used my silver Sharpie and made a small mark at 2 1/2 inches.


I ran the actuator back in and got it as close as I could to the mark. That’s where I’ll leave it until it’s installed.


I have to take it all back apart for deburring and painting, then I’ll do the final reassembly.

Time: 4:20

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