Archive for category Rudder
Rudder Stop Installed (5/25/10)
Posted by Ethan Jacoby in Construction, Empennage, Rudder, Vertical Stabilizer on May 26, 2010
0.5 Hours -
With very little left to do on the empennage, I went ahead and installed my internal rudder stop. Nothing complicated…just clamp it in place and use the holes in the rudder stop to drill holes in the hinge bracket for two AN3-7A bolts. Once drilled, I used AN3-7A bolts with two washers and a stop nut on each. Everything was torqued to 25 inch pounds, inspection lacquer applied, and done!
The rudder stop is pre-drilled for AN3 bolts. The hinge must be match-drilled.
The rudder stop is mounted using AN3-7A bolts and stop-nuts. I also used two washers per bolt to adjust the grip.
On another note, my wing kit shipment, originally scheduled for mid-May but delayed to mid-July, has been bumped up the priority list at Van’s. My kit went to crating on Monday and will be shipped as soon as it is all boxed up. In two or three more weeks, I should be back to some serious airplane building!
Internal Rudder Stop
Posted by Ethan Jacoby in Construction, Empennage, Rudder, Vertical Stabilizer on May 20, 2010
Rudder stops are another one of those RV things where you can ask 5 people and get 10 different opinions. After reading as much as I could about the pros and cons of internal vs. external stops, I decided to purchase an internal stop. At $25, it isn’t a big loss if i decide not to use it (and I can probably get $20 back by selling it to another RVer).
If following the plans as Van’s has written them, the rudder stops are pieces of aluminum angle that are riveted to the aft fuselage just forward of the rudder. At full deflection, the rudder horn will hit these stops before the rudder skin smashes into the elevator. By modifying the angle of the stops, you can alter the amount of swing in the rudder. While this works well, I think it is unsightly. Granted, the rudder cables hanging out of the fuselage are a little ugly too, but at least one ugly can be eliminated.
The internal rudder stop is simply a chunk of delrin plastic that is milled to a specific shape and drilled for two AN3 bolts. The plans for this stop are available for free on vansairforce.net, or a pre-cut stop can be purchased from Merlin Enterprises (Stockton, CA) for $25. I chose to buy the finished product since the purchase of raw material, combined with my time to make two of them (because I will screw up the first!), will easily surpass $25.
The infamous internal rudder stop...some love it, some hate it.
The internal stop is bolted to the top half of the lowest rudder hinge on the vertical stabilizer using two AN3-7A bolts (if I measured correctly). When the rudder swings to its limits, the rudder spar will contact the stop, preventing further movement. The down-side of this system is that some people believe the stop, when in contact with the rudder, will stress the aft-most fuselage bulkhead. However, no one has done a complete stress analysis, it is believed that the only stress severe enough to cause damage would occur only in an aggressive maneuver such as a tail slide (I’ve got bigger problems if this happens), and there are over 500 RVs that have implemented the internal stop. In my opinion, concerns some builders have are unfounded. If my rudder jams in-flight, I’ll change my opinion 
The rudder stop will attach to the lower rudder bracket on the vertical stabilizer with two AN3 bolts.
A bigger view of the vertical stabilizer for reference. The rudder stop is on the top half of the bottom hinge bracket.
Top Rudder Tip Installed (4/3/10)
Posted by Ethan Jacoby in Construction, Empennage, Rudder on April 3, 2010
1.5 Hours -
For my third tip, I decided to install the top rudder tip. I’m avoiding the horizontal and vertical stabilizer tips for as long as I can because those have to be closed before they can be installed.
The rudder tip required a bit more work than the elevator tips, but it is the best looking of the three so far. As with the two elevator tips, the flange of the rudder tip had to be trimmed slightly in order to allow it nestle up against the flange of the rudder’s tip rib. In addition, a short section of the flange at the aft end of the tip had to be completely removed to accommodate the AEX wedge in the rudder’s trailing edge. I ended up removing about one inch of the aft flange.
After trimming the flanges, the tip still would not fit well on the forward end. I really had to squeeze the tip to get the forward end to slide into the rudder. The problem here is that the forward surface of the tip does not have a flange built into it like the rest of the tip…it is simply flat. Therefore, I decided to make my own flange by sanding away the gel-coat with my Dremel’s sanding drum. Once my homemade flange was complete, the tip slid into place easily and fit perfectly.
The initial trim of the top rudder tip requires that some material be removed from the bottom of the flange. Also, a portion of the aft flange must be completely removed to allow for the rudder's AEX wedge.
To make the forward portion of the tip fit, I had to create a flange of my own.
The initial fit looks ok...time to drill.
My girlfriend came home with some snacks for me!
With the fit acceptable, I proceeded to drill the tip to the rib. Initially, I drilled the holes to #40. They were then enlarged to #30. However, the aft three holes on each side were already drilled to #30 and dimpled during rudder assembly per the plans. If I had not done this earlier, it would have been almost impossible to dimple them now. For these holes, I very carefully match-drilled the tip using only a #30 drill.
Once drilled and clecoed, the fit looks great.
A second view of the final fit.
Once drilled, I deburred and dimpled the holes in the rudder. The holes in the tip were countersunk, once again, using my Dremel with a conical grinding bit. I also glued aluminum rivet washers to the inside of each hole on the tip as I did on the elevators. After the glue on the rivet washers had some time to set, I went ahead and attached the tip using CS4-4 blind rivets.
The final result looks very good. There is less waviness in the seam than is on the elevator tips, and there is only a very slight gap on one corner of the forward face of the tip. I put a picture of this gap below, but the camera makes it look much bigger than it actually is. As with the other tips I’ve done so far, I’m planning to leave it as it is now. If I decide to paint the plane later down the road, I may glass over the seam and fill the gaps at that point.
The tip is riveted on and is easily the best fitting of the three tips I've done so far.
There is a small gap in the corner...the picture actually makes it look bigger than it really is.
The trailing edge lines up nice, but the tip is wider than the aluminum. I may sand this down or add filler to even it up later.
Rudder Finished…Finally! (1/9/10)
Posted by Ethan Jacoby in Construction, Elevators, Empennage, Rudder on January 9, 2010
3.8 Hours -
This morning, in San Antonio, we woke up to a temperature of 15 degrees! I had to go to work briefly, and, by the time I went into the garage, it had warmed up to a toasty 32. Despite the cold weather, good progress was made on the RV.
While I waited for my parents to arrive, I deburred the rivet holes in the left elevator stiffeners and removed the vinyl from the left elevator skin. Once my parents were here, I put the elevator aside and my Dad and I focused on the rudder.
As a recap, I glued the trailing edge of the rudder, using tank sealant, about a week ago. Now that the sealant should be fully cured, it’s time to free it from the aluminum angle and rivet it with double-flush rivets. I coated all the clecos and the aluminum angle with Boelube which alloyed us to easily remove everything. However, some traces of excess sealant were present in the dimples and we had to clean this out. Using a #40 drill, turned in our fingers, we could loosen the sealant enough to pull it out with our fingers.
Some excess tank sealant had to be removed from the trailing edge rivet holes.
My Dad busy removing excess tank sealant from the trailing edge rivet holes.
Once all the holes were cleared, we placed 3-3.5 rivets in each hole and taped down the factory heads with rivet tape. The rudder was then flipped over and placed on a back rivet plate. I then back-riveted every tenth rivet just enough to set the rivet. If I did this properly, the rivet wasn’t even half set. Once every tenth was set, I went back and set every rivet about half-way.
Every tenth rivet is partially set to lock everything in place.
We then flipped the rudder over once more. To fully set the rivets, the shop heads were placed on the back-rivet plate, and I used a mushroom set in the rivet gun to hit the factory heads. The resulting double-flush rivets look great on the factory side, with the factory head completely filling each dimple. The shop heads do not completely fill the dimples, but are perfectly flush. Van’s instructions warn that the rivets will not completely fill the dimple, and you shouldn’t use longer rivets in an attempt to fill the dimples. Van knows more about building planes than me, so I went with the instructions and the finished trailing edge looks great. I wouldn’t call it razor sharp, but it is definitely straight!
Trailing edge rivets fully set.
With the trailing edge wrapped up, it was time for us to move on to the leading edge. The edges of the two rudder skins have to be rolled together and then pop-riveted. The technique to do this seems crude. A dowel is duct taped to the skin. Then, using a couple of vice grips, you roll the edge upwards. This is repeated on the other surface, and, if all goes well, the skins meet and can be easily final drilled and riveted. Well, it wasn’t easy, but my Dad and I got it done. It took a lot of finagling and some finesse to work the pieces together, but the end result looked good and the rudder was finally done!
A dowel, duct taped to the the rudder, is used to bend the leading edge.
A closer view of the finished rudder leading edge.
With the leading edge rolled and riveted, the rudder is finally done!
Next, it was time for a little wood work. I needed to construct a small brake for making the final bend on the trailing edges of the elevators. To make this, we just used hinges to connect two 1”x8”x4’ boards lengthwise. We left a 1/8” gap between the boards and used 6 hinges in all. While it wasn’t complicated to make, I definitely prefer working with metal!
A homemade bending brake for making the final bend in the elevators.
Rear view of the bending brake.
Black Death (12/30/09)
Posted by Ethan Jacoby in Construction, Elevators, Empennage, Rudder on December 30, 2009
1.8 Hours -
Finally, I was able to get back to work on the RV today. First, I quickly fixed a bad blind rivet in the rudder. I noticed this rivet was standing proud of the rib prior to moving, but waited to fix it until now. I’ve read that removing blind rivets is difficult, but this one was easy. I drove out the shaft, drilled into the head, popped off the head, and pushed the shank out. Thirty seconds later, a new LP4-3 rivet was set…this time, properly!
With that done, it was finally time to glue the rudder trailing edge. I clamped the rudder parts together with my match-drilled piece of angle and did one final check of the alignment. Everything looked good, so I took everything apart and prepped it for gluing.
The trailing edge clamped together before gluing to check alignment.
Another view of the ready-to-be-glued rudder.
Some reading gave me some tips on how to make my first endeavor with tank sealant a painless one. I started by generously rubbing some Boelube on the aluminum angle and on the shafts of all the clecos that would be used to clamp the glued rudder together. I’m hoping that the Boelube will act as a releasing agent for any areas that shouldn’t be glued together such as the clecos and the rudder, itself, to the angle.
Next, I found everything that I would need for the entire process. This included rags, acetone, nitrile gloves (extras too), and the tank sealant kit.
The 1 ounce sealant kit from Van's contains a jar of goo, a packet of goo, and a stick to mix the two goos together and make a super goo!
With everything ready, I could no longer delay dealing with the “black death.” When I mixed the sealant together, I quickly understood how it obtained the “black death” nickname. This stuff is stickier than anything I’ve every encountered. It is stringy like melted mozzarella cheese, slightly thicker than peanut butter and immediately sticks to anything it touches.
Once mixed, the sealant reagents make a very sticky compound affectionately referred to as "black death."
Using the supplied popsicle stick, I spread the tank sealant evenly on both sides of the trailing edge wedge. Then, I changed gloves in an attempt to keep the rudder clean and carefully slid the wedge into place between the rudder skins. The rudder assembly was then clamped to the aluminum angle using my Boelubed clecos. When clamped, some of the excess sealant oozed out, but this was surprisingly easy to clean with an acetone soaked rag. After cleaning up, I did one final check and everything looked nice and straight! The rudder will now sit for at least 4 days to allow the tank sealant to fully cure before riveting.
A bead of sealant oozed out when the rudder was clamped together. Using an acetone soaked rag, clean-up wasn't too bad.
Nice and straight. I'll unclamp and rivet in about a week.
Finally, I started to rough cut the stiffeners for the elevators. As with the rudder, Van’s supplies some stock that is notched. The notches indicate where to cut, resulting in perfectly sized stiffeners. I completed the rough cuts on 13 stiffeners…16 are left to be cut.
13 elevator stiffeners rough cut, 16 to go.
Using tank sealant is definitely a messy task. However, it really wasn’t that complicated to apply. Using it on the fuel tanks shouldn’t be an issue.
Four More Rivets In The Rudder (12/9/09)
Posted by Ethan Jacoby in Construction, Empennage, Rudder on December 9, 2009
0.1 Hours -
My second order of rivets arrived from Van’s today. I love their quick service on these small orders…and their prices are descent too.
This order contained twenty MK-319-BS blind rivets. I only needed two, but I want extra on-hand just in case!
It only took me a couple of minutes to set these rivets. I also set two more LP4-3 blind rivets in the tip rib which I forgot from earlier. With these four rivets in, the rudder is now completely assembled except for the trailing edge. I’ll glue and rivet the trailing edge as soon as I get moved into the new house.
0.1 Hours Worked Is Still Worth a Log Entry (12/7/09)
Posted by Ethan Jacoby in Construction, Empennage, Rudder on December 7, 2009
0.1 Hours -
My first of two orders from Van’s arrived today. This one contained a bunch of LP4-3 pop rivets and 1 ounce of tank sealant.
I really only needed one rivet to finish the rudder, but I decided to get 40 to have some on hand. They’re cheap at 5 cents each, so why not! The 0.1 hours of work came from placing the last pop rivet in the rudder brace assembly.
The tank sealant will be used to glue the trailing edge before riveting. However, this will wait until sometime after the move.
More Rudder Final Assembly (12/6/09)
Posted by Ethan Jacoby in Construction, Empennage, Rudder on December 6, 2009
1.0 Hours -
I was able to get a little more work in on the rudder today. I finished setting all the rivets I could in both ribs. I tried the back riveting method in the EAA videos (use a thin bucking bar on the shop head and a back rivet plate on the factory head…use the rivet gun to hit the thin bucking bar), but I couldn’t get this to work very well for me. I could set the rivets, but they often weren’t flush. I also tried to set a few with my squeezer, placing a flat-headed nail into the hole where a flat set would normally go. Essentially, this gave me a no-hole yoke. This worked ok, but the nail was only good for one rivet before the head would distort. A real, 4″ no-hole yoke would be nice to have. All the remaining holes will have to wait until I receive my rivet order from Van’s.
I also countersunk both sides of the trailing edge wedge. Not complicated, but definitely time consuming. Once the wedge was countersunk on both sides, I also primed it.
I’ll finish riveting everything but the trailing edge as soon as my order comes in. However, I’ll probably leave the rest until after I move into the new house.
Sorry, no pictures today.
Continued Rudder Assembly (12/5/09)
Posted by Ethan Jacoby in Construction, Empennage, Rudder on December 5, 2009
5.3 Hours -
My girlfriend and I will be moving in a couple of weeks. The good news is that I’ll soon have a two-car airplane factory. The bad news is that I’m scrambling to get the rudder to a stage where I will be comfortable moving it. This means everything needs to be done except for gluing/riveting the trailing edge. Today, I was able to make pretty good progress towards this goal.
Continuing rudder skeleton assembly, I riveted the counterweight rib to the spar and then riveted the counterweight skin to the rib. When I tried to install the lead weight, it didn’t fit due to the rivet shop heads that were now protruding into the rib. To fix this, I filed away a bit of the weight near the forward-most rivets. Then, I used my rivet gun, with a flat set, to gently “nudge” the weight into place before tightening the screws/nuts.
Riveting the counterweight skin to the rib.
I used my rivet gun to "finesse" the counterweight into place. I also filed away some of the lead on the sides.
Next, I set the rudder skeleton aside and match drilled a piece of angle to the rudder trailing edge. To do this, I laid the skin on the angle and center punched the hole locations. Using my drill press, I then lined up each punch mark and drilled them. Finally, I screwed the angle to the edge of my table. The trailing edge will eventually be glued and then clamped to this angle. If all goes well, the angle should keep the trailing edge perfectly straight.
I match drilled a piece of angle to the rudder trailing edge. This will ensure that my rudder is nice and straight.
After finishing the angle work, I resumed assembling the rudder. After clamping both skins to the spar, it was time to start riveting. First up was to rivet the main skins to the counterweight skin and the spar. On each side, there were 6 rivets for the skins and 3 for attaching the skins to the spar. I couldn’t reach the bottom-most rivets with my squeezer so I had to buck them by hand and space was tight! Otherwise, it was just a matter of paying attention to which size rivet to use in each hole.
Several rivet sizes are used when riveting the counterweight skin to the spar and main skin.
Next, I clecoed in the tip rib. I’m out of LP4-3 blind rivets, so I couldn’t rivet the rib to the spar just yet. Leaving this clecoed should be fine for now.
Finally, I started riveting the skins to the skeleton. Almost all of these rivets could be reached with my squeezer. There were about 8 rivets attaching the right skin to the spar that I had to buck. Also, some of the aft-most rivets on each of the ribs can not be squeezed. I left these for now, but I’ll have to buck them tomorrow.
Started Rudder Final Assembly (12/3/09)
Posted by Ethan Jacoby in Construction, Empennage, Rudder, Tools on December 3, 2009
1.4 Hours -
My order from onlinemetals.com finally arrived yesterday. The two pieces of metal I received were a 5 foot long piece of aluminum angle and a 6×2 inch piece of 3/16” cold rolled steel. The aluminum is for keeping the rudder trailing edge straight, while the steel is for making a combination female dimple tool and thin bucking bar for tight spaces.
To make the dimpling tool, I simply drilled a #40 hole in one corner of the steel and then countersunk it to accept a AN426AD3 rivet head. I then repeated this on the opposite side with a #30 drill for –4 rivets.
I countersunk a piece of thin steel to serve as a female dimple die. #30 on one side, #40 on the other.
Using this was not as easy as I had hoped. You really have to swing hard with the hammer while holding your parts in place. To make a dimple, I placed the rib over the hole in the steel bar, placed a male dimple die through the hole from the top, placed a socket over the male die’s shaft to protect it from the hammer blows, and hit it with a hammer. It would normally take two or three blows before the dimple would be acceptable.
The bucking bar plus male dimple die makes an ok dimple. The socket protects the dimple die shaft from the hammer.
The dimple on the left was squeezed. The one on the right was made with my bucking bar set up...not bad.
Once I finished dimpling all the holes in the ribs that I could not get to with my squeezer, I started final assembly of the rudder skeleton. I started by riveting the spar reinforcement plates and nut plates to the spar. Then, I assembled the bottom rib/rudder horn assembly.
One of the rudder reinforcement brackets installed with the nutplate.
Everything was going well until it was time to rivet the rudder brace to the rudder horn. Some builders have been able to find a way to use solid rivets here and squeeze them with their longeron yoke. I couldn’t figure out a way to get my longeron yoke to fit, so I chose to use the optional LP4-3 blind rivets. Unfortunately, when I pulled out my bin of LP4-3 rivets, there were only three left and I needed four.
I went ahead and set the three rivets I had and left the fourth hole with a cleco in it. Fortunately, this won’t hold me up as there is nothing that will block my access to this hole during subsequent construction steps. However, I did stop here for the evening and immediately placed and order for LP4-3 rivets and some fuel tank sealant from Van’s.
The rudder horn, reinforcement plate, spare, rib assembly
I ran out of LP4-3 rivets for attaching the rudder brace. I'll order more from Van's tonight.
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