Category: Flaps

With my experience on the left flap, I am able to jump into getting the right flap done in short(ish) order. I am trying to keep my experience on the left flap forefront in my mind, but even still I’m bound to miss something.

The hardest part for me has been motivation. Looking at the collection of parts and all the sanding, deburring, drilling, and riveting has kept me from working on on the project a bit. It was from sheer force of will that I would go into the garage to just make progress. Some days it was just to file down the edge on a few ribs, other times it was just to disassemble part in prep for priming or some other task. Either way, just keep making small steps and things continue to move forward!

With that all said, I basically follow the same steps as the left flap. Nose ribs and sub-components were already created, but I start to assemble the flap skeleton. Lots of match drilling, then start fitting on the skins. Match drill all the skins. Then it’s deburring and prep for primer.

With all the components primed, you slowly start to assemble. Dimple the necessary parts and rivet the sub-components. Then assembly onto the spar. I actually missed putting the edge break onto the skins prior to dimpling so I ended up having to manually do it with the duckbill pliers. Not as pretty as with the edge break tool, but turned out fine.

Rivet the top skin to the ribs, and the bottom skin to the spar. Remember not to install the blind rivets until you have the trailing edge in place. I also fabricated a TE cleco surface out of a Home Depot piece of angle aluminum. 8″ long and 2-1/2″ wide, drilled with the same hole spacing as the TE wedge. This gives me a nice flat surface to cleco the TE and skins to when I use proseal since my workbenches are not 100% flat.

With the pro-seal set, I then install the blind rivets on the bottom skin, then double-flush rivet the trailing edge. After cleaning up a few spots of proseal, both flaps were completed and mounted temporarily on the wings. I’ll need to remove them and the ailerons to get the bottom skins installed but that looks like it will be in another year or so (just before or after I move the project to the airport.). Only thing left is to pressure test and possibly repair any leaks in the fuel tanks then it’s full steam ahead on the fuselage.

With the parts dimpled, and the sub-components riveted together, it was time to begin final assembly of the flap itself. I had read ahead on the plans and realized I needed some new drill bits for the blind rivets. I ordered a #33 jobber bit but didn’t realize I needed a long bit to clear the hinge plates on the nose ribs. Another order submitted for a 6″ bit. While I was at it, I also decided to purchase a close quarters rivet pulling wedge vs fabricating one.

I did have a “manual to implementation” issue with the flaps (Things got lost in translation in my grey matter). I misread / misunderstood the order of operation and ended up blind riveting the bottom skin to the ribs BEFORE I installed the trailing edge. While not the end of the world, it did make the installation of the wedge a bit more difficult than it needed to be. (The flap looks straight so far, but will check and verify against the other flap to make sure.) Worst case is I build a new flap at some point. (wont be the first thing I have to re-order!)

I also had a new tool that I decided to try out – a Trailing Edge squeezer set from cleaveland tool. Instead of setting the double flush rivets with a backrivet plate and a flush set in the rivet gun, you use these angled rivet sets in your squeezer that are aligned with a large safety pin? It’s hard to describe, but it seems to work. Between this new tool and my out-of-order assembly I’m waiting to decide if my flap trailing edge is really as straight as it should be. (I’ll also have some EAA chapter friends give me some feedback).

With everything done, I then press-fit the bushings in the wing side flap brackets (don’t do this unless you are done with the bottom skin), and install the flaps. All look good and I’m excited for another component to be completed. At this point I just want to mark the wings as done (or done for now). Still need to complete the other Flap, finish sealing the tanks, and make a decision on the bottom skins.

I decided to put the fuselage work off to the side as the next steps will start to take up significant space in my garage. Instead, I am focusing on finishing up the last few items on the Wings as I will need some significant workbench space to complete them.

Before I jump to the flaps, I decided to drill the aileron torque tube endcaps just to knock them off my list. Next on my hit-list are the flaps. I went ahead and began by sorting and marking all of the ribs and components for both sets of Ribs. I then deburred and modified the components based on the plans in the manual.

With everything sorted, I then began to create the different assemblies for both right and left flaps, drilling and deburring as necessary. Once all the sub-components were ready, I then focused on building out one flap at a time due to space constraints.

Assembling and final drilling the flaps was pretty straight-forward with no real surprises. The only gotcha I ran into was I did not own a uni-bit that could drill a 1″ hole to reduce the weight of the FL-1008 Spacer (Page 22-3 Step 3). A quick search of Amazon got one shipped in a few days.

With all the components prepped, I marked the locations of all the parts, then disassembled to prepare for primer. I ended up doing 3 different primer sessions as tried to work around my family schedule, weather, and sanity. Ended up forgetting the spar, only to have to do that by itself, then realized that I only sprayed one of the nose skins. More head slapping than anything else.

With the parts primed, I being to dimple and assemble the components. I start with the hinge brackets and rib assemblies. Then I move on to skins and spar. I had not deburred the side of the skin that wasn’t primed, or some of the edge, so that needed a little attention. Other than that the instructions are straightforward if not time consuming.