Flap Hinge Pin Secure

I am just about wrapping up the wings but wanted to get a few more items out of the way now so I don’t have to worry about them later.  Here you can see how I decided to secure the flap piano hinge pin.  It goes on easy and is very secure.

We have Flaps

Over the last couple days I worked on the flap egress holes..  The egress holes are holes right through the bottom of the fuse where the flap pushrods go.  I started by just mounting the flap bolt/bearing without the pushrod, then found where it contacted the fuse and trimmed to fit.   Basically this takes you up the side of the fuse a bit and underneath.  Vans marks places where this hole starts too which helps.  Once the bearing was clear, I lowered the flaps all the way to see where the rod ended up.  Cut the hole to that location using my dremel and a small sanding drum... Then wouldn't you know it after about 2 hours on the first side, and a third hour on the second side I have flaps.  They work great, up, down, up, down..  Bekah even likes them.  ;-)

Flaps Complete

Today was a long day completely focused on the right flap.  I primed it yesterday and riveted it today.  Got through the entire flap in about 2.5 hours.  Things on the wings are wraping up.  Next step is figuring out how to rivet on those bottom skins.  Will need to pull Bekah in on this one.

Left Flap Complete

Last night I riveted away and finished up the left flap.   Tricky in spots, but overall turned out pretty good.  I kept checking to make sure it was straight but you really don't have the ability to rivet it like the aileron on a flat table.  By the time you can get it to a flat table, most of the rivets holding it together are set.  Anyway, at the end of the day I was able to put it on a flat table and I couldn't identify any twist.  That is all I can hope for..

Now it is onto the right flap, then finishing up the bottom skins and the wings will be structurally complete !

At this point, however, I have decided to abandon the project all together.  Realizing the impact it has on my life and the expectation of 2-3 more years of this really is starting to get to me.  It will be sad to give it up, but probably better for my state of mental health..  I will be donating my wings to the societad du avion aou francis early next week.
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Flap Riveting

I am finding that although tricky in order, the final riveting of the flap is pretty easy.  I guess I might take back some of the words I said yesterday about it being as hard as the ailerons.  All up they may be easier, but I am not done yet and I hope it doesn't end up warped, which the directions say can easily happen.

Here the flap is in the stand I built which holds the shape as you take the spar out to reach the inside for bucking.  I also realized that I am able to shoot and buck these myself, so I am not needing to pull in Bekah's assistance on this one.

Here you see inside the bucked rivets that I was able to get to with the tungsten bucking bar.  Tape evenly wrapped around it makes for a nice stable bucking set up.  Also, a small piece of cardboard in the bottom of the flap (not shown) covering the rear spar adds safety.

I am leaving the end ribs till last to make sure I am able to test the straightness before setting those.  In this picture you can see the nutplate and the challenge I will have at bucking that rivet underneath it.

Another problem that I am having is that the alumiprep I use to etch the aluminum before priming must not have gotten washed off all the way.  As you can see in this picture, it left a etching behind on the surface skin of the underside of the flap.   I think the only way I can fix this now is to finish prep in this area and then prime over it.  Luckily it is on the bottom so not as obvious, but I will need to do this to both flaps now so that the final look is even until the paint job is complete..  ugh

Left Flap Final Assembly

The instructions indicate that the flaps are the simplest control surface to build for the RV.  That simply isn't true, other builders have indicated such and I agree.  There is much more fabrication and the rivet/final assembly stage is much more unique and "tricky" than with the ailerons.

Here I am begining final assembly and you can see I have already riveted the root rib and stiffeners together.  As well, the stiffener is riveted onto the spar, but they are not riveted together since the spar must be removed in a later step.  Also, I have installed the nutplate for the actuator bolt and clecoed everything together except for the top skin.

 

Riveting the final skin on there are several rivets that you can't reach.  The only way to get in is by removing the main spar, so a jig needs to be made which I will do tonight.  Even then you are blocked by the rear spar, so on the inboard rib, the final two rivets on the top skin and bottom must be pop rivets.  Also, many builders have trouble getting to the rivet under the nutplate, so we will see how I do.  Maybe the tungsten bucking bar will save me here.

As I said riveting order is key, I have also already riveted the back of the inner ribs to the rear spar.  Once you start getting the skin in place, this also in unreachable.

Flaps - Yes, I still am using alodine..

I am still using alodine and here is the proof..  At least I use it for all parts that fit into my alodine bath that is already set up and just gets pulled out when the time is right.  Most builders I think stop using this stuff after the empenage because it is an extra step and not a very healthy on at that since the stuff can be pretty bad for you.  I should probably stop, but I have it and it does provide much better corrosion protection, so I am sticking to it for now.

The process starts with dipping the part in the alumiprep bath, then rinsing, then dipping in alodine for a few minutes and rinsing again.

Here you see my set up, and the final product.  I full set of innards for both the right and left flaps ready to prime.  For the skins, hinge, and spar I will only use the alumiprep because they won't fit in my bath...  After the alodine you see the desired gold color that will resist corrosion for years.

Flap Deburring/Dimpling/scuffing and more prep

I started out the weekend taking the flaps apart just to clean them up abit.  There really is a lot of drilling on these and the mettal shavings get between layers and everywhere.  Once I got them kind of cleaned up I countersunk the spar where the flap hinge attaches.  The directions indicate sjuch so you don't have to dimple the soft hingle aluminum which provides extra strength.  After the one side of the spar was countersunk, I assembled the flaps and drilled the skins.

After the skins are drilled, the 3-4 hours of deburring and dimpling takes place.  Every little step takes much longer than you expect.  Don't forget the soldering iron on the skins to remove to top layer of plastic..    However, after a days work, I have both flaps at the same stage and ready for the scuffing, alumiprep and alodine treatment.

Flaps

What a mess.  The flaps require a lot of drilling and fabrication of angle to make the required support, also many of the holes are not full size so you need to drill them out creating a lot of metal everywhere.   I made tons of progress tonight though and apart from the match drilling of the skins I am almost ready to prime both flaps.  I saved the skins because I want to clean up this mess a bit before I get them out and start working with them.  The flaps are quite visible and I want them to be fairly pristine.

Here you see both skeletons all drilled and fabricated.  The inboard rib takes the most work, you need to bend the doubler you see in the picture to approx 6 degrees and then fabricate the joining stiffener out of angle and drill all holes through the spar and through each stiffener.  I am happy to say I am keeping both flaps at the same stage through this process.  Tomorrow I will make final match drill for the nutplate that connects to the flap actuator and final drill the top skin.  Then onto deburring, countersinking and dimpling for the final steps and priming.

Ailerons complete, on to the flaps

Wow, I can't believe it has been a week since my last post.  I was a bit busy with work last week though, but no excuse.  ;-)  This weekend I was able to finish up the second Aileron, and did a lot of work on the wiring and rigging in the wing.  Just some random pictures here.  I might send my wiring pics around to some other homebuilders to get a feel for how I am doing.

Here are some pics Bekah took as we did the final riveting on the left aileron.

Here you see the Autopilot roll servo and bell crank complete.  Things to look at here are the torque seal, the primed spacer tubes, the 7 wire connection is basically D-sub pins and sockets surrounded individually by shrink tubing then the entire bundle in a larger heat shrink tube.  Also where I exited the conduit, I used a zip tie and RTV silicon to prevent chafing.  The wire naturally pulls itself away from the servo bell crank parts, but I also used a sticky zip tie holder that is used by homebuilders in general to tie off electric wiring.  If you ask me this will last 20 years in a high vibration environment.  Oh, and also note the cable RG-58 for the wingtip antena.  I routed it around the aileron servo and used bushings through the rib web.  Van's said this was OK.  I also did some work on the pitot tube electrical, and will get some pictures up of that shortly. 

I also got a healthy start on the flaps; Fitting the skeletons together and drilling out the hinge.  You can see the clamps I used to keep the hinge inline while I drilled.