I’ve been recording most of my build sessions and I finally got around to compiling all of the ones related to the rudder. I decided to only use the ones showing the final assembly of the rudder because videos of nothing but deburring are not very interesting. Sorry that the lighting and camera angle are not always great.
I’m actually writing this about two weeks after we finished the rudder but I set the date of the post to match when we finished the rudder.
Meggin and I spent 1.4 hours re-rolling 2 of the 3 sections of the leading edge of the rudder. I believe it was a 3/4 inch PVC pipe that worked the best for us on the smallest section of the leading edge. On the middle section we used a 1 inch pipe and then tried switching to the 3/4 inch pipe, but that ended up rolling the skin too much so after trying one side we decided to call it good where it was. We then clecoed the leading edges together, final drilled the holes (including adding two new holes on both sides of the hole I mangled with the cleco), deburred as best we could and riveted the leading edge!
The plans also say that if the skin pillows out where they were folded over the counter balance weight then you can add an additional rivet in between the screws on that section. I decided to do this because I apparently didn’t fold the skins perfectly, so it bulged more that I liked.
These two pictures were from work I did on a different day but they show some of the work I did to bend the skins over the counter weight.
The rudder isn’t perfect but now that it’s finished I’m actually pretty happy with it. It’s taken longer than it should have since I replaced so many parts but finally having a part of the plane finished is an AMAZING feeling!
Once I got that shear clip in the rudder fixed I was finally able to move on to the next steps. This involved getting the rudder spar riveted to the rest of the rudder. It uses several blind rivets to join it to the shear clips and then solid rivets to join it to the skins. For the solid rivets, I started by using my pneumatic squeezer with the 4 inch no-hole yoke because it is the only one I have with the reach to get past the skin on some of the rivets. This worked pretty well but I didn’t like how slanted that yoke makes the rivets due to how much the yoke flexes so I switched to the rivet gun with the flush set and a bucking bar. I’m not very good with the rivet gun yet so I ended up putting a small dent in the skin. That’s when I got my wife to help me. She used the gun and I held the bucking bar. This worked much better than doing the rivets by myself.
Next up was the trailing edge. We went slowly and followed the instructions in the plans and I am happy to say that it was pretty uneventful. The edge never seemed to start to curve or get wavy at all. Here’s the best photo I could get of the edge.
Unfortunately the leading edge didn’t go as well. The plans recommend using a 1 1/4 inch pipe to roll the leading edge so I went to Home Depot and got a
1 1/4 inch PVC pipe (I accidentally bought 1 1/2 inch pipe instead of 1 1/4). The problem with that was that the inner diameter of the PVC pipe is 1 1/4 1 1/2 inches but the outer diameter is closer to 2 inches so when I tried to roll the edge with it I was barely able to get the edge to bend at all. Luckily I had some 1 inch PVC pipe which had an outer diameter closer to 1 1/4 inches. This worked better but I didn’t do a very good job. Part of the problem was that I cut the pipe down to be a little longer than the largest section of skin that I needed to roll. This didn’t give me much room to grab the pipe to roll it, especially on the shorter sections of the skin because this meant the pipe was right up against the spar. For the last two sections I rolled, I had my wife’s help and I used a much longer section of pipe that stuck out well past the end of the rudder so I could really get the leverage on the pipe that I needed to be able to roll the edge as far as I could.
I should have gone back and done all of the other edges I tried to roll with this longer section because they weren’t rolled nearly far enough. This meant that it took a lot of effort to get the skins together to try to cleco them. I got only a couple clecos in before I realized I need to do a better job rolling the edges and tried to take them out. By the time I got one of the clecos out I had a hole that looked like this:
Things had been going so well on the rudder for that last few days and that made this really upsetting. I was thinking I would drill out the damage and then make a plate that went behind this hole and extended to the holes on each side but another suggestion I received was to just put additional rivets next to the hole. I think I’ll do that since it should take less work than making a plate to fit behind all of the holes.
It’s been a few weeks since I’ve added any blog entries talking about what I’ve done on the build so I’m going to get caught up in one post.
I’ll starting off with the rudder shear clip problems I had. For the first shear clip I removed that had a couple enlarged holes, I followed Van’s recommendation and just used the next size larger blind rivet for those two holes. For the second shear clip I needed to drill out, I ordered a 90 degree drill which worked slightly better for most of the rivets. I still didn’t have the drill bit perfectly lined up with the rivet while I was drilling it out and that led to one misshapen hole. For the second rivet I drilled out with it, I was using a smaller drill bit than the rivet. This loosened the rivet up enough that the rivet was spinning with the drill bit and when I tried to pull the bit out of the rivet, it snapped off inside of the rivet. After emailing with some local builders I decided to dry to use a dremel tool to cut/grind the rivet with the drill bit out of the rudder. It was difficult to use because it was a very tight fit but the grinding bit actually caught the part of the drill bit that was stuck in the rivet and pulled it out of the rivet far enough to grab with pliers so I could pull it out. I went ahead and tried to drill the rest of the rivet out with a larger bit which actually just snapped the rivet head off so it came out really easily. Luckily the last two rivets were uneventful. The holes were so messed up at this point that I had to reorder the part. Since the holes in the stiffeners had matching mangled holes, I an idea that Van’s suggested for the first clip, and I fabricated a backing plate to go on the other side of the stiffeners. Here is what that looked like after it was all riveted together:
While I was waiting on the replacement parts for the rudder I started to rivet the rudder hinge brackets to the VS spar. One thing to be aware of is that the rivets the plans call for that go through the rudder hinges are a little short. I drilled two rivets out that I set before I realized that the reason they were squeezed way too thin wasn’t because of how I set the squeezer. So for these I used the next longer rivet size. Here are the two rivets that were too short for the hinge brackets.
Using the squeezer worked really well until I got to a couple rivets on the hinge brackets where the squeezer just won’t fit so I had to use the rivet gun. This was going ok until I lost control of the rivet gun and it walked down the spar for a few inches. This put some small dents in the spar and really ruined my night but after chatting with Van’s they don’t think it is bad enough to be a problem and said to just smooth out the spots where the gun dug into the metal and re-prime it. Here is what it looked like:
When I moved on to the upper rudder hinge bracket I thought I was doing pretty well until I looked at the rivet heads on the manufactured rivet side. If you look at the rivet in the picture above where the gun dug into the rivet before it stared walking down the spar you can get an idea of what I did to those rivet heads on the upper rudder hinge bracket, except they were much worse. They were bad enough that I felt I should drill them out and replace them. As with all of the other rivet drilling I’ve done this didn’t go so well. Clearly I need to practice doing it on some scrap but in this case I can also blame the rivet heads, particularly one of them, because of how badly I messed it up while riveting. This is the result of my struggles to get the rivet out:
Due to all of the damage I did to that reinforcement plate I knew I should replace it, and also confirmed that with other builders and Van’s. Luckily Van’s pointed out to me that since I’m replacing the part directly under the manufactured heads of those rivets, that instead of drilling them out (which as we know now will probably lead to me damaging more of the spar) I should just grind off the heads of the rivets and then punch them out. I haven’t done this yet but I’m hopeful that I can do it well enough to salvage the rest of that spar assembly. Here’s a picture showing the whole spar assembly so far.
I’ve done a lot of deburring on the first few HS parts that are worked on. The spars for the HS are around 11 feet long so they take up a lot of space in the workshop and the edges take a while to finish. I did get a little bit of final drilling done on the rear spar for the spar doubler and the elevator hinge brackets. I also riveted together what the plans call the inboard hinge bracket assembly. This was nice and easy and left me feeling pretty good about myself.
So I realized that the rudder stiffener being on the wrong side of the shear clip shifted its position just enough to make it very difficult, maybe even impossible, to get all of the rivets through the holes that connect the shear clip to the rudder spar. This made me decide to attempt to drill out the rivets so that I could reposition the parts. I had a couple options on how to drill them out. With a jobber length drill bit I could fit the drill between the other shear clips and stiffeners with no trouble, but because of the diameter of the drill motor, I didn’t like the angle that the drill bit would go into the rivet. To attempt to fix this angle I decided to use a 12 inch drill bit that I would flex, using a gloved hand, so that it would get into the right position to drill the rivet out without turning it into a hole. It seemed like a good idea at the time but in hindsight I should have bought/borrowed a 90 degree drill instead.
This is what my technique looked like. Due to the length of the bit I had to position it between the stiffeners right next to the drill.
I started off slowly and checked my progress on the rivet after a small amount of drilling. Looking good so far…
Got the first rivet drilled out and I’m feeling like this might actually work out.
Three rivets later…
The bottom right hole is the picture above is nearly perfect…I’m not sure how I pulled that off. The other three are not quite as good, with the top left being the worse. The holes in the picture may or may not look very bad to you, but when I insert some rivets to check the size there is a lot of extra room. I’ve emailed Van’s to see what my options are for this part. My biggest concern at this point is that the stiffeners this clip was attached to now have matching holes. It will be really easy to replace the shear clip, but if I have to replace the stiffeners as well that will mean a lot more rivets have to be drilled out which gives me a lot more changes to mess up other holes.
I won’t touch the rivets for the other clip that needs to be repositioned until my 90 degree dill gets here, which I’ve already ordered. Until then I think I might start riveting together the vertical stabilizer.
Today started off simple enough. When I countersunk the trailing edge wedge in the rudder a while back it worked very well on one side, but since the hole was enlarged by the first countersink the countersink cutter ‘chattered’ a lot when I was countersinking the other side. The result was the really rough holes you can see in the picture below.
I cleaned up these holes using a hole deburring tool and some elbow grease. Next my wife and I got everything set up to bond the trailing edge of the rudder together. The plans point out that a straight trailing edges on the control surfaces is very important and can affect the feel of the airplane if they aren’t straight. They suggest bonding the trailing edges together before you rivet them using either fuel tank sealant (which is an old method but still used by a lot of builders) or really sticky double sided tape. I decided to try the sealant this time since it is still a very popular method, and I hoped it would provide a strong enough bond to hide some of the dents I put in the trailing edge of one skin a couple weeks ago.
The basic process when working with the sealant is after you mix the two components together, you apply a thin layer to the trailing edges of the skins and then cleco them and the wedge together. You start at one end and roll on skin onto the other. While you work your way from one end to the other you rivet, using blind rivets, the stiffeners and the shear clips on the rudder skins together.
My wife and I went over the plan a few times to make sure we knew what we were going to do, but despite that we still ran into problems. It’s amazing how thick and sticky the sealant is. This makes spreading a thin layer on the trailing edge very difficult. You really want a thin layer because if it is too think then it can apparently prevent the two edges from coming together nicely. Oh, one more thing, the sealant has a working time of 30 minutes, and it took me about 20 minutes to get the sealant mixed and applied to the entire trailing edge wedge (the plans say to apply the sealant to the trailing edge but I chose to put it on the wedge so that it would be exactly where I needed it). So this meant we really had to hurry to get the rest of the process done, which resulted in some riveting errors.
When I set the first blind rivet the two stiffeners were not as close together as I thought which caused the rivet to expand a little between stiffeners. So now the two pieces are being held slightly apart from each other by the rivet. It’s tough to see but at the center of the picture, where the parts form the sideways ‘V’, is where the two parts are being help apart.
A little bit later I wasn’t paying attention to the position of the stiffener in relation to the shear clip. In the picture below you can see that the bottom stiffener attaches behind the shear clip and the top one attaches in front of the shear clip. Well, both of those should be behind the clip. Unfortunately I didn’t pay attention when I set the rivet that connects the stiffeners together, which is at the left of the picture, and once that rivet is set it isn’t possible to get the stiffener to the other side of the shear clip. Since I was worried about finishing within the sealant’s working time, I just set the other rivets and hoped it would be ok. A couple minutes later I did the same thing to another set of stiffeners…
These are pretty minor problems that I don’t think really need to be fixed. Regardless, I have sent out an email asking some other builders for their opinions on if they would fix them, and how difficult it is to remove the blind rivets. I’m really frustrated that I made these mistakes but it’s also nice to have the rudder that much closer to being finished.
Over the last couple days I got the stiffeners riveted to the other rudder skin, the top rib halves riveted to each skin, and the bottom rib with the rudder horn riveted to one skin. I did skip a couple rivets on the bottom rib because it got too tight to get a squeezer or bucking bar in there so I have to research how to set them. I also got the shear clips riveted to the stiffeners using blind rivets. Blind rivets work a little bit differently than the other rivets I’ve used so far. Blind rivets are like hollow cylinders with a rod that stick through it with a ball on the end. You stick the rivet into the hole and then use a tool to pull the rod which then deforms the bottom of the rivet which creates the shop head which holds everything in place. Once the rivet is fully set the rod snaps off and you’re all finished.