Archive for category Leading Edges
More Spar Countersinking (12/6/10)
Posted by Ethan Jacoby in Construction, Leading Edges, Main Structure, Wings on December 6, 2010
0.4 Hours -
The good news is that I received my new left inboard leading edge rib from Van’s today. The bad news is that I still have to deburr, flute, drill, dimple, scuff, prime, etc., before it is any good to me. It will probably have to wait until the weekend. However, I was amused by Van’s packaging for this rib.
The rib was the only item in my order, so it came in a large padded envelope. When I first saw the envelope, I thought that it was a pretty poor job of packing. When I opened the envelope, and saw how the rib was packaged, I remembered that the people at the factory are masters of safely packing pieces of metal into small spaces. The rib was laying on a piece of cardboard, which was larger than the rib. The rib/cardboard was then wrapped in layer upon layer of plastic wrap. Seriously…way more plastic wrap than needed, but I don’t care because my rib was in perfect condition.
Van's definitely packs items well. From left to right: my new rib, the padded envelope, cardboard, and plastic it came wrapped in.
Once the rib was unpacked, I used the leading edge skin to roughly mark on it where the holes will be drilled (this is the only leading edge rib that is not pre-punched…the reason why I messed it up in the first place). These marks will allow me to flute the rib and, hopefully, not end up with a flute were a hole needs to be.
Then, I decided to set the rib aside for now so that I could continue prepping the spars for final assembly with the leading edges and skins. I managed to make 90 countersinks on the bottom side of the left spar before deciding to call it quits. That still leaves me 20 or so countersinks to finish on the bottom and 110 or so on the top!
Leading Edge and Spar Work (12/5/10)
Posted by Ethan Jacoby in Construction, Leading Edges, Main Structure, Wings on December 5, 2010
3.0 Hours -
I started off the day by finishing up the riveting on the left leading edge. However, I broke up the riveting with some countersinking on the right spar. After driving a dozen or so rivets, I would be ready for something else, so I would pick up the drill and work on countersinking the spar for the leading edge and skin dimples. After a dozen or so countersinks, I would return to riveting. Unfortunately, there was a lot more countersinking to do than riveting, so eventually, I just focused on the countersinks.
While riveting the leading edge, I managed to ding/dent the skin on two rivets for the stall warner mount plate. I do have the occasional ding while riveting, but I think this is the first time I’ve done it on two rivets in a row. I’ve added a picture of the dents…the picture is very close-up, so the dents look worse than they actually are. The camera really has a way of bringing out any flaws in your work.
While riveting the stall warner mount plate, I managed to dent the leading edge skin on both rivets. The picture makes the dents look much worse than they actually are.
By the end of the day, I had the left leading edge completely riveted except for the inboard-most rib. That rib has to wait until my replacement part arrives from Van’s.
I also managed to finish all of the countersinks and deburring on the bottom side of the right wing structure. I’ll still need to countersink/deburr the top side before I can attach the leading edge. In addition to countersinking/deburring, I’ll also need to dimple all of the ribs and the aft spar. In other words, there are many little things that need to get done before I can start the permanent assembly of the wing. Unfortunately, those little things are also the things that take the most time!
More tedious countersinking and deburring on the main wing structure.
More Left Leading Edge Work (12/4/10)
Posted by Ethan Jacoby in Construction, Leading Edges, Wings on December 4, 2010
2.5 Hours -
This morning, I went to the garage and finished dimpling the left leading edge skin using a c-frame. Once this was done, I scuffed the inside of the rivet lines and sprayed some primer.
After dimpling the skin, I primed only along the rivet lines on the inside of the skin.
Once the primer dried, I riveted the stall warner access reinforcement ring to the skin. Initially, I planned to back rivet this…I even had the rivets taped in place…but, then I realized that I could reach them all with the squeezer. Since the squeezer is the simplest way to rivet, I opt to use it whenever I can!
Ready to start riveting, I clecoed the access reinforcement ring to the skin.
All of the rivets for the access reinforcement ring could be reached with the squeezer...easy!
A view of the access reinforcement ring from the inside.
After the reinforcement ring was riveted, I clecoed all of the ribs to the skin (except for the inboard rib, since I’m waiting for a replacement rib) and then took a break.
I clecoed all of the ribs (except for the inboard...still waiting for the replacement part to arrive) to the skin in preparation for riveting.
Later, in the evening, I returned to garage and started riveting the ribs. As with the right leading edge, I worked from aft to forward, squeezing the top two rows of rivets and shooting/bucking the rest. I ended up quitting with 6 rows of rivets, on each side, still remaining. My riveting was starting to get a little sloppy, so I figured I better quit for the evening before I make any major mistakes.
As with the right side, I squeezed the top two rows and bucked the rest of the rivets.
Left Leading Edge Rib Final Prep (12/3/10)
Posted by Ethan Jacoby in Construction, Leading Edges, Wings on December 3, 2010
1.3 Hours -
Not much to report tonight. All I did was work on the final prep of the left leading edge ribs. These needed to be deburred, dimpled, scuffed, cleaned and primed.
Yes, another priming picture.
Left Leading Edge Skin Prep (12/2/10)
Posted by Ethan Jacoby in Construction, Leading Edges, Wings on December 2, 2010
1.2 Hours -
Tonight, I finished deburring all of the holes in the left leading edge skin. I also deburred the edges of the skin and dimpled all of the holes that could be reached with my squeezer. The holes that couldn’t be reached with the squeezer will have to wait for another day.
The next thing I needed to do was to cut a slot for the stall warner vane in the leading edge. Cutting the leading edge flat-out makes me nervous! Van’s helps a little by punching two hole in the leading edge as a guide for the cut. The slot, itself, is made by connecting the two punched hole. I made the cut using my Dremel…first with a cut-off disc to make the rough cut, then with an odd little carving bit to finish it off. Once the slot was cut, I used a small strip of emery cloth to smooth the edges and make sure the sides were nice and round. As usual, I was worried over something that was really quite easy!
The leading edge had two small holes punched in it by the factory, I had to turn the two holes into a slot for the stall warner vane.
I used my Dremel to make the cuts, then sanded with some emery cloth. Not bad, if I don't say so myself!
Stall Warner Assembly (12/1/10)
Posted by Ethan Jacoby in Construction, Leading Edges, Wings on December 1, 2010
1.9 Hours -
Today is my girlfriend’s birthday, but, since she has to spend her birthday at school, I get to work on the plane! Her birthday dinner will have to happen another night.
Back to work on the stall warner assembly in the left leading edge.
The exploded view of the stall warner assembly from the plans.
I started by clecoing the VA-195F mount bracket to leading edge skin and final drilling all the rivet holes. Since the leading edge isn’t assembled yet, I’ll be able to use solid rivets to mount the stall warner rather than the blind rivets called for if doing a retrofit on a completed wing.
The VA-195F mount bracket is riveted to the inside of the leading edge. This will hold the stall warner assembly.
The VA-195F mount bracket inside the leading edge.
Once the rivet holes were drilled, I removed the mount bracket, deburred, dimpled and primed it. The Duplicolor primer I’m trying is working OK, but there are a couple things I don’t like about it. Mainly, it doesn’t seem as durable as the NAPA 7220 primer, and the Duplicolor has to set almost overnight to ensure that it is durable enough to continue working on the part. The NAPA primer, on the other hand, seems to set and be ready to work with rapidly. I also prefer the light gray color of the NAPA primer as opposed to the dark green of the Duplicolor (its the little things).
Next, I started working on the VA-195E mount plate and VA-195B keeper plate. I drilled and countersunk these parts according to the plans, then deburred and primed them.
The VA-195E mount plate and the VA-195B keeper plate both need to have some drilling, countersinking, and deburring done before they are ready.
The corners of the VA-196 stall vane also needed to be rounded a bit. This took all of 10 seconds to complete.
Once all the primer was dry, I put the stall warner assembly together. Other than the fact that there are a lot of tiny washers to handle, assembly was straight forward.
This is the stall warner microswitch. I'm not sure why, but Van's included two switches when only one is needed. I'm sure I'll find somewhere else to use the second one.
The completed stall warner assembly, viewed from the top.
The completed stall warner assembly, viewed from the side.
With the stall warner assembly put together, I moved on to the access cover plate for the leading edged. This piece only needed to be deburred and dimpled for #6 screws.
The leading edge access cover plate was simple...deburr, dimple, done.
Finally, I started to deburr the left leading edge skin. I only made it through the rivet holes on one side of the skin…the rest will have to wait. I also need to buy a good crimper. Some of the wiring for the stall warner will be completed now, and it will be my first wiring task on the plane. I only have one of those cheapo crimpers with the red handles…definitely not aircraft grade, so it looks like I’ll be making my first purchase from SteinAir soon.
Leading Edge Work (11/28/10)
Posted by Ethan Jacoby in Construction, Leading Edges, Wings on November 28, 2010
5.3 Hours -
Seeing how long it took me to rivet ribs in the fuel tanks, I wasn’t sure how long it would take to rivet the right leading edge ribs. The leading edge construction is almost identical to the tanks. However, none of that nasty sealant is needed.
All clecoed up, the right leading edge is ready to rivet.
I clecoed the right leading edge together, with clecos in every hole. The instructions have you rivet from the aft end forward. This is opposite the tanks, where Van’s has you start at the front and work back…not sure why this is. The two aft-most rows of rivets could be reached with a squeezer, so I squeezed those on both sides and then pulled out the rivet gun.
The top two rows of rivets could be squeezed, but the rest had to be bucked.
With the rivet gun, I worked forward, row by row, until the leading edge ribs were completely riveted. My riveting was very clean, only having to drill out and replace two rivets. Surprisingly, the whole process only took a couple of hours…I wish the tanks would have been that easy!
The right leading edge took me only a couple hours to rivet...not having to use sealant makes things go so much quicker.
Later in the day, I returned to the garage and started working on the left leading edge. The first thing I did was to pull the joint strip and finish that. As with the previous joint strip, I had to drill attach holes for the nutplates, then deburr, dimple, and prime the aluminum strip. Once the primer was dry, I riveted the nutplates in place.
Then, I moved the left leading edge from the wing to my workbench. This is where I noticed a problem. The rivet holes on the inboard rib (where the joint strip goes) were very close to the bend on the top side of the rib. This rib did not have holes in it originally. They all had to be drilled when the rib was in place on the wing along with the skin and joint strip. When drilling it, I thought the holes were ok, but on closer inspection, with the rib removed from the leading edge, it was clear that the holes were way too close to the bend and there would be no way to dimple them.
I thought this rib was ok when I drilled it, but when I took the leading edge apart, I found the holes on the top side of the rib to be too close to the bend...redo!
This is what the holes should look like...close to the center line of the flange.
Wondering if there was a way to salvage this rib, I checked Vansairforce.net to see if anyone else had this problem. As usual, I wasn’t the only one, and the overwhelming recommendation was to replace the rib since holes too close to the bend can weaken the rib. After seeing this, I went ahead and ordered a new rib from Van’s. This isn’t too bad of a mistake at just under $30 for the new rib, and drilling it should be easier the second time around since I can make a line down the middle and be able to see that line through the holes in the skin and joint strip.
Next, I decided to start working on the stall warner system. I’ve gone back and forth as to whether or not to install this. If the leading edge skin wasn’t already pre-punched, I would have left it out for sure. However, since the new kits are already punched, I figure I might as well install it rather than just filling the holes with rivets. The system is very simple. A small, metal vane sticks out the leading edge. This vane is attached to a small switch. If you approach a stall, the vane will move, triggering the switch to signal a tone generator to do its thing. The tone generator is wired directly into a headset jack, but since my plan is to install an AOA system, I’ll likely not connect the stall warner to the headset jack. However, it will be nice to have it ready incase my panel planning changes.
All I managed to accomplish on the stall warner was to finish the access panel reinforcement ring (VA-195C) that goes in the left leading edge. This was much like finishing the joint strips…I just had to deburr, prime, and rivet on some nutplates. I also enlarged a tooling hole in the left spar to accept a snap-bushing for the stall warner’s wiring.
The access reinforcement ring for the stall warner had to be deburred, dimple, and primed, before I could rivet on the nutplates.
Right Leading Edge Final Prep (11/26/10)
Posted by Ethan Jacoby in Construction, Leading Edges, Wings on November 26, 2010
3.0 Hours -
Today, I managed to get three hours of work in on the airplane in between football games and a trip to the hardware store. I bought a hole saw set to use in fixing the leaks in my fuel tank. I’m planning on cutting 3″ holes in the baffle and using 4″ covers, so I played with those sizes of hole saws a bit just to see how well they will work. They’re a bit like a fly-cutter…a lot of noise for a very small cut. At least the hole saws aren’t as scary as the fly-cutter!
Later, I disassembled the right leading edge so that I could start the final prep of all the parts. I deburred all of the holes, in both the skin and the ribs, using my Avery deburr tool. I then dimpled the ribs, and as many holes in the skin that could be reached with the pneumatic squeezer. The remaining holes in the skin had to be dimpled with the c-frame. I also deburred the edges of the skin using a vixen file to knock down any notches, and then I ran a Scotchbrite wheel over them.
Dimpling the right leading edge skin with the c-frame.
Close up of dimples in the LE skin. These were all done with the squeezer.
Next, I scuffed all of the mating surfaces for priming. Previously, I would have primed the entire rib, but I’m starting to realize that the primer is really overkill. So, I’m now just priming the mating surfaces. This equates to the flanges of the ribs and the rivet lines on the skins.
After scuffing, I cleaned everything off with acetone and started priming. I quickly ran out of the NAPA 7220 primer that I had remaining, so I switched to some Duplicolor self-etching primer that I had purchased. I’ve heard fairly good reviews on the Duplicolor primer so, when I found some on sale, I bought it. Even at full price, the Duplicolor primer costs less than the NAPA. As I sprayed it, I immediately noticed that the Duplicolor nozzle sprays a thicker coat of primer compared to the NAPA. The Duplicolor is also darker in color and seems to dry a bit slower. However, I’ll have to wait until tomorrow to see if the Duplicolor is as durable as the NAPA 7220.
The Duplicolor primer (right) is darker and seems to go on much thicker than the NAPA primer (left). I'll have to wait until tomorrow to decide if the Duplicolor is as durable as the NAPA.
The leading edge skin and ribs are all finished and primed...time for assembly.
Right Tank Leak Test Take 2 and Back to the Leading Edges (11/25/10)
Posted by Ethan Jacoby in Construction, Fuel Tanks, Leading Edges, Wings on November 25, 2010
1.5 Hours -
Its Thanksgiving Day, and I had a little time to work on the plane before we head to my parents for dinner.
I started off the morning, by retesting the right fuel tank for leaks. I really didn’t have very high hopes for the quick fix on this tank, but it was worth a shot. Unfortunately, the quick fix made the leaks even worse. Instead of leaking at the baffle/skin seam, the sealant filets just redirected the leaks so that the air now comes out of the skin/baffle rivet row.
Since the right tank still leaks, I’ll go ahead and do the major fix that is recommended by many builders. To do this, I’ll cut 3″ holes in the baffle using a hole saw. I’ll have to cut one hole in each bay of the tank, then reach in and reapply sealant to the inside of the skin baffle joint. I’ll put it on very heavy this time. Once the new sealant filet is in, I’ll cover the holes with 4″ diameter pieces of aluminum and some closed end pop-rivets (which I already ordered, since I didn’t think my first fix would work anyway).
Once I finished the leak test on the right tank, I removed the right leading edge from the wing and started to disassemble it for final prep. The only part I managed to finish was the joint strip. I had to drill the strip for nutplates, then deburr, dimple and prime the strip. Finally, I riveted the nutplates in place using some 3-3.5 “oops” rivets.
I used the actual nutplates as guides for drilling the joint strip.
Here the joint strip has been primed, and all the nutplates are attached.
I used oops rivets to rivet the nutplates to the joint strip.
Leading Edges Finished…For Now (9/6/10)
Posted by Ethan Jacoby in Construction, Leading Edges, Wings on September 6, 2010
4.0 Hours -
Today, my work on the airplane was very slow-going, and it resulted in two bent drill bits, one drilled finger and bunch of neighborhood kid becoming incredibly interested in finding out what I’m building in the garage. The goal for today, which I achieved, was to finish the leading edges to the point where it is time to move on to the fuel tanks.
I started by getting the leading edge inboard ribs ready. Unlike all the other ribs, these ribs are not pre-punched. Using the holes in the leading edge skin as a guide, I roughly marked the locations where the holes will be on the rib. With these marked, I could straighten the rib and not end up with a flute where a hole needed to be.
Once each rib was straightened, I inserted it into position on leading edge/forward spar and drilled the spar to rib holes. Then, I had to prepare the joint plates (W-423).
The joint plates are just strips of aluminum (already cut to size by Van’s). My job is to mark where the holes will be drilled, bend them, jam them between the inboard leading edge rib and leading edge skin, and then drill them at the same time the inboard rib is drilled using the holes in the skin as a guide. Simple enough.
Van’s has you draw a line 1/2″ from the edge of the joint plate. This line serves as an alignment guide for drilling since it can be seen through the holes in the skin. If the line can be seen through the holes, 11/16″ of joint plate should be left exposed. Later on, this exposed portion will receive platenuts for attaching the fuel tank. After the line is on the joint plate, I pre-bent it using one of the inboard ribs as a guide.
Next, I had to insert the joint plate between the inboard leading edge rib and the skin. This is a really tight fit, requiring a little pounding with a soft mallet to get the joint plate in place.
A line drawn on the joint plate is used to position the joint plate under the skin.
Once in place, I hade to carefully measure to make sure the proper amount of joint plate was exposed and the rib was in the proper location. I then started to drill the joint plate and rib using holes in the skin as my guide. After each hole, I would insert a cleco and then carefully recheck the alignment before moving on to the next hole. On one of these holes, I had my hand in the wrong spot on the back side and got nicked by the drill bit…not too deep or painful, and I managed to keep all the blood off the aluminum!
Partially drilled, getting everything to align is a serious pain.
The outboard leading edge rib and joint plate.
Another view of the outboard leading edge rib and joint plate.
Once this process had been repeated for each hole on the inboard rib, I started final drilling the rest of the holes on the leading edge. While doing this, I managed, to “set down” my drill a little harder than intended a couple of times, causing me to bend two #40 drills. I guess I’ll have to order some more.
A picture of me final drilling the leading edge skins.
Finally, I used a unibit to enlarge the holes for the tie-down eye bolts. This was pretty simple to do, but it would be easy to destroy the threads in the tie-down assembly if you try to go to fast.
The tie down eye bolts fit nicely after I enlarged the holes with a unibit.
It was kind of interesting today because a bunch of neighborhood kids kept coming over to watch me work. At first, they just stood at the sidewalk and watched, coming and going occasionally on their bikes. Eventually, a girl decided to ask what I was making. When I told her it was an airplane she said, “cool,” and ran off. She must have told her friends because she returned with two other kids a few minutes later. As if they didn’t believe her, they also had to confirm that I was building an airplane. Of course, they wanted to know if it was a real airplane and where I would fly it. When I told them it was a real airplane and I could go anywhere I want in it, the first girl gave the newer kids a big, “I told you!”
The leading edges are now finished until it is time to take everything apart before riveting. The next line on the instructions says, “Assembling the fuel tanks.” I’ll be elbow deep in black death (tank sealant) soon enough!
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