Riveting the Wings Rear Spar

I found a little time to finish up the rear spars for the wings tonight.  I had let the AKZO cure for a few days while Tammy was off so we did family time during those days.  Tammy was back at work tonight, so I pulled the primered parts from the booth and riveted them together. I started out on the left rear spar since it is the one that is specifically shown in the plans.  The right one is not in the plans, and Vans assumes we know how to mirror the left for the right wing.  First thing was to cleco the doublers to the rear spar as well as the reinforcement forks and its doubler plate.

Next, we have to carefully match up which holes need rivets, as some of the holes will be used to hold the spar, doublers ribs and even the gap seals for the aileron and flaps. I used masking tape at first to cover up the holes that don’t get rivets right now and then clecoed everything together.

In the last photo above, you can see where I just used a sharpie to mark the holes the DO NOT get rivets instead of using masking tape.  After looking over the plans, we are only going to be using three different rivet sizes.  AN470AD4-4 for the thinner doubler plates, AN470AD4-6 for the reinforcement fork to rear spar, and finally AN470AD4-8 for the reinforcement fork, its doubler plate and the rear spar.  To make my work more efficient, I decided to start with the smaller rivets first, setup my squeezer for them and then do all of the 4-4 rivets on both rear spars, and then just adjust the squeezer for the next size and repeat.  So, I went ahead and clecoed the right wing rear spar parts together, making sure to mirror their orientation to the left wing.  Since there are only a few rivets on some of these doubler, I just decided to circle the ones I needed to squeeze instead of using masking tape for the right rear spar.

Then it was time to squeeze.  I started out with the AN470AD4-4 rivets and adjusted my squeezer until the rivet was setting perfectly against the rivet gauge, and the I went and squeezed all of the 4-4 sized rivets on both the left and right rear spars, always checking each one with the rivet gauge (I am picky about this). Once I had them all done, I moved up to the AN470AD4-6 rivets and did the same thing for both sides, and then finally finished up by riveting the handful of the larger AN470AD4-8 rivets. Each rivet was checked with the gauge for precision.

You’ll notice that on the reinforcement fork, I set the rivets with the manufactured head on the thickest metal.  While this isn’t technically correct, I needed to be sure I would have space to squeeze the wing skins in the holes directly above those rivets.  However, on the thick doubler plate to reinforcement fork, you’ll notice that I did indeed set these with the manufactured head towards the thinnest (rear spar channel) metal which is technically how it should be.  While there is debate on how this should be done, this will be fine since even though the rear spar channel is indeed thinner than the reinforcement fork, it is still a thick piece of metal itself.  Had I been riveting the very thin skins to something thicker, I would made sure to put the manufactured head on the skin side. Here’s the required selfie of me and the completed rear spars to help prove I actually did the work for the repairmans certificate.

And that is pretty much it for tonights session.  It was only about 1 hour and 45 minutes of work for tonight, but this actually completed the assembly of the rear spars.  They will go back on the shelf along with the main spars until I have all these ribs deburred, drilled and primed; then I’ll pull them off the shelf and build the wing skeletons. Rib prep will be consuming quite a bit of time for the next couple of weeks, so I am going to have my metal wing stands built during this time frame, hoping they’ll be ready by the time I am done with the ribs. Here’s the photos from tonights work:

Google Photos Link:  https://goo.gl/photos/NX9zek3fvUcWvmSR7

Hours Worked: 1.75

Prepping the Rear Spar

There wasn’t much left to do on the rear spars except finish getting them ready for priming, and then riveting.  The bulk of tonights work was deburring all the holes, so thats where I started off.  I deburred all the holes in the doubler plates (W-707E, and F), reinforcement fork (W-707G) and reinforcement doubler (W707D), and the rear spar main channel web (W-707A). Once I had both sides of all the parts deburred for the left wing, I swapped over to the right wing and did the same there.  There wasn’t much to photograph for this work, since its just deburring all these holes.

I realized I didn’t drill the holes on the flanges of the doubler plates W-707E and W-707F so I clecoe’d them to the rear spar and then match drilled using the holes in the flange as a guide. Once I had the holes drilled, I followed up by deburring them as well.

I read a little bit ahead in the plans and noticed that Vans gives us some warnings of things that we should address now before we rivet the rear spar together.  The first thing is that the outboard doubler (W-707F) needs to be countersunk for a few rivets.  After looking over the plans, I see there are 4 holes on the most outboard of the rear spare that calls for AN426AD4-5 flush head rivets.  Well, instead of machine countersinking this fairly thin metal, I decided to just use my DRDT-2 dimpler, since it would easily handle this thickness.  I dimpled the W-707F doubler and then followed up with dimpling the rear spar channel to match.

The next thing Vans warns about before riveting is that we should probably go ahead and final drill to #40 and then dimple the rear spar top flange because when we rivet on the reinforcement fork and its doubler plate, it would be difficult to dimple them afterwards. So, I broke out the drill with a #40 bit, final drilled the holes, and the used my squeezer to dimple the rear spars top flange holes all the way to the end of where the reinforcement bar would land.

I also decided to go ahead and dimple the rear spar top flange where the doublers (W-707E and F) attach just so they wouldn’t be in the way.  I final drilled to #40, and then used the squeezer to dimple the holes on the rear spar flange, as well as the doubler plate itself and made sure they still would nest together.  The squeezer very slightly bent both pieces to a 90 degree angle, where it normally is a bit more angled, so I used my hand seamers to gently bend both pieces back to their normal position.  It was a very gradual bend.  After completing all the above on both wings, I called it a night.  The parts are ready to be primed, which I will probably do tomorrow. Here’s the photos from tonights work:

Google photos Link: https://goo.gl/photos/vYgtM8yGBy4hzTXNA

Hours Worked: 2.5

Assembling the Rear Spar

Got a little bit of a late start, I had to run out to Harbor Freight after work to pickup a die grinder for the work tonight, and ran a few other errands, but I managed to put 3.5 hours in, and have the rear spar ready for metal finishing and then priming. I am at the start of the “Assembling the Rear Spar” section of the plans, and the main spars are done for a few more steps.  The session started out by deburring all the edges of the rear spar parts: W-707A rear spar channel, W-707E and W-707F doubler plates, W707G reinforcement fork and the W-707D rear spar doubler. I deburred the edges using the scotchbrite wheel, which made quick work of the parts, even the long rear spar channels.

Then, Vans has us trim away a decent chunk of the W707G and W707D doublers since this is an RV-7.  I studied the plans for a bit and then made the careful measurements, and marked the lines.  Stupid me forgot to take photos of my marks before I made my cuts, so I don’t have a good way to show how I did it, but here is the part of the plans that gives the cut dimensions:

I first decided to cut the W-707D Rear Spar Doubler first, since it would be cheap and easy to ship in case I messed it up. Note how the shaded part is angled a bit and there are 4 measurements I had to make and then mark.  Once I had my marks made, I connected the marks with a straight line using a machinists ruler. After confirming everything was right, I decided to cut it using my bandsaw with a metal blade.  This is thick aluminum, so snips was not an option and I figured I would cut with the bandsaw and then grind away any odd cuts or un-eveness from the saw.  It actually turned out really nice, and only needed a very small amount of grinding!

Once I had this piece looking right, I used it as a template for the others.  I have to make this same cut on the W-707D for both sides, as well as the W-707G reinforcement forks for both sides.  I just cleco’d the freshly cut doubler against the other pieces, and marked the edge with a sharpie, and cut them on the bandsaw.  After grinding the edges and deburring them to a smooth edge on the scotchbrite wheel, they were done.

Now that I have all my rear spar parts deburred, trimmed and ready to go, its time to start assembling and drilling both rear spars. I clamped W-707E and W-707F doublers into their locations. W707F was pretty easy, since it mounts flush against the most outboard edge.  The W-707E needed some measuring.  The plans calls out to place the most outboard edge of the doubler 50 and 3/4″ from the outboard edge of the rear spar channel.  Once they were both in place, I clamped them down with side clamps and then match drilled all the holes to a #30 after double checking all the rivet sizes in the plans.

This is the easy one!

Measuring for 50 and 3/4″

Once I had all the rivet holes drilled to size, the next step is to cut out the hole for the aileron pushrod in the doubler plate.  I flipped the rear spar over, and use the pre-punched hole in the spar to mark the location for to transfer the hole to the doubler plate.

Then, I used a unibit to drill out the largest section of this hole, and used a #40 drill bit to drill out the smaller section.  This is to get everything started so I can file, grind and trim it the rest of the way.

Once I had the holes to about close as I could get (notice there is still some black sharpie lines to be trimmed out in the photo above), I removed the double and used a combination of files (round, and flat of different sizes) and then fired up the die grind with a small grinding wheel to grind down what remained of the metal.  I then finsihed up the holes with a scothbrite pad to remove any burrs that may have been left behind. I am pretty happy with how they turned out.  They are slightly larger than the hole in the rear spar, but I think that’s fine.

Next up was to just repeat these same steps on the right wings rear spar.  I did the aileron hole a little different, but drilling even more #40 holes to make the grinding and filing go a little quicker which seemed to have help cut down on the time it took. I still used the unitbit in the larger middle-ish section which removed about 97% of the metal I needed.

I still had a little steam left, and I wanted to get these rear spar parts completed to all that was left was hole deburring and then priming, so I pushed on to the match drilling of the W-707G reinforcement fork and W-707D doubler plate.  I studied over the plans to make sure that all the holes were using a #30 drill, and then clecoed the reinforcement fork and doubler plate to the rear spar channel.  I did both rear spars at the same time since it was easier this way.  Then, lastly, match drilled all the holes to #30 on both rear spars, and marked the parts which was left and right.

Thats it for tonight.  I’ll save the deburring of the holes for tomorrow, and possibly a priming session on Sunday.  Whenever I prime these rear spar parts, I’ll also prime the tie-down brackets so they can go ahead and get mounted up.  Here is all the photos from tonights work:


Google Photos Link: https://goo.gl/photos/Yjaue9L3JMiy9Jgf9

Hours Worked: 3.5

Drilling the Elevator Horns

This is pretty much the last step on the empennage kit! It’s time to double check all the measurements and alignments and drill the last holes on the tail….the elevator horns.  I have read horror stories of people not getting this done correctly, and having to have the horns welded up and re-drilled.  So, I approached this with caution. Before mounting the elevators, I measured the eye bolts one last time with my dial calipers to make absolute certain that they were all to plan specs.  Then I started off by mounting both elevators and measuring them yet again through its entire travel.  I was getting well within the limits of Max up/down travel so I decided its time to drill.

I started off my removing the right elevator so I could drill the horn for the left.  Then, per the plans, I clamped the elevator so that its in trail with the chord line of the horizontal stabilizer.  We do this by clamping the elevator counterbalance skin to the horizontal stab skin using some scrap sheet aluminum and a few clamps.

Then I did a real good eye ball check to make sure the horn was going to be lined up, and I wouldn’t have any clearance issues after it was drilled.  This is something I had seen crop up on other builders, and some of the had issues getting the bolt head and nut to clear the horn assembly.  Luckily everything looked good, so I decided to drill.  Van’s tells us to use a drill bushing in the VA-146 bearing assembly to help align the hole on the horn.  I had picked up from some other builders that a 1/16″ ferrule and collet seem to work really great as a drill bushing and they are cheap at Lowes / Home Depot.  So, I visited the aviation section of my local Home Depot and picked up a few packs of these things:

The little collets are exactly 1/4 outside diamater and they fit perfectly in the bearing!   I had to use some gorilla tape on the end of the bearing to hold the collets from sliding out, and I ended up using a total of 4 of them in the bearing.

The tape does nothing but hold the collets in to keep my fingers out of the way. I found a drill bit that fit perfectly in the hole in the collets and used it to drill my pilot holes.  With a little bit of finesse and gentle drilling. I had my pilot hole done!

Next up was to drill the pilot for the right elevator, so I removed the left elevator and set it aside for now.  Then, I mounted up the right elevator, clamped the counterweight to the stabilizer and drilled its pilot hole using the exact same method as I did for the left.

Now its time to drill this pilot hole to its final size.  After removing the right elevator, I set both it and the left on my work bench to secure them for final drilling.  I decided against using the convenient step bit for this because they have a tendency to wander, and this is pretty precision work. I started out by drilling the holes out from smaller to large using these drill bit successions:  #40, #30, #27, #21, #12 and finally the 1/4 size needed for the AN4-14A bolt. Then, I deburred the holes.  The front side was easy, but the back side was a little tricky, so I got creative:

The angle drill worked great to get this tight spot deburred.  Now that the holes were drilled to the right size for both elevators, its the moment of truth: Checking for binding.   I re-mounted the elevators to the horizontal stabilizer, and then inserted the AN4-14A bolt through the horn, into the bearing and through the other horn……it fit! Everything aligned correctly and there was absolutely no binding at all in the entire hinge line.  Its moving through full deflection as smooth as butter.

The horns look a little wonky, and like they’d be out of alignment, but according to Van’s and the mindshare on Vans Airforce, this is totally normally due to the manufacturing differences in the horns. So long as the hinge line doesn’t bind there is nothing to worry about.  I do have plenty of clearance for the bolt head and nut to thread on nicely as well.  These parts are DONE!! I removed the elevators and then thoroughly tightened the jam nuts on they eyebolts.  The horizontal stabilizer and elevators will go on the shelf until they are ready to be mounted to the fuselage.

I still had a little steam and energy left, so I decided to test fit the rudder and make sure it’s in good shape.  I double checked the eye bolt depth with my dial caliper, and then mounted it to the vertical stabilizer and moved it through its full deflection and there was no binding! It also moves as smooth as butter and looks great.

With that, the tail kit is pretty much done! I am going to leave the fiberglass work until the very last of the build, and all thats left now is to drill a hole in the horizontal stabilizer and rudder horn for the tail light.  I am thinking I will go ahead and do this now, since its easy to get to and I have some spare bushings to use.  Then, I will label and bag up all the remaining mounting hardware (bolts, washers and nuts for the hinge lines) and put everything away until I get ready to mount it to the fuselage.

As a side note, I have ordered my Wing kit and am waiting on the invoice and crating dates.  Its looking like an 8 week lead time…but I will put that info in another post.  Here’s the photos for tonights work:

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Google Photos Link:  https://goo.gl/photos/Qvx8CEUQNj1pvk9K7

Hours Worked: 2.5

Riveting the Vertical Stabilizer Rear Spar

I worked about 2 hours tonight on the vertical stabilizer rear spar. I also spent a few minutes coming up with a way to mount my horizontal stabilizer on the wall to keep it safe and out of the way.  For about 2 bucks in hardware, here’s what I came up with:


And it actually looks pretty decent against the wall.  At the very least, I will have some nice looking aviation related wall art 🙂


After that, I continued on to working on the Vertical stabilizer.  Vans has us start on the rear spar of the vertical stab by clecoing on the Vs-803PP spar to the VS-808PP doubler, as well as the hinges VS-410PP, VS-411PP and VS-412PP.  I also taped off the holes where the VS-704, VS-706 and VS-707 ribs would rivet on later, so I didn’t accidentally rivet those holes.  img_0843

Once I had everything clecoed in place, and taped up, I was ready to rivet.  The plans have a myriad of different rivet lengths due to the thickness of the doubler, and the hinge plates so I started out by riveting on the VS-412 hinges at the top of the spar.  Once I had those on, I moved to the shortest rivet size group and worked my way up to the longest.  Eventually I had all the universal head rivets squeezed with my squeezer, and I could finish up with the bottom section of the spar.  This section I previously dimpled and countersunk because we need to use flush rivets on the face so that the spar will sit flush on the fuselage when we mount it.  So, I put my flush set in my squeezer, set the depth and set all those flush rivets on the bottom, finishing up my vertical stabilizer rear spar.  It came out looking really nicely!


Here are all the photos from tonights work:

And here is the Google photos link: https://goo.gl/photos/JJZC2YV1fNmMq3mVA

Hours Worked: 2

Dimpling the Right Horizontal Stabilizer

I didn’t have much time tonight, I was working on my parade car most of the day. But, I did find a little over an hour to get some work done on the airplane.  My beam torque wrench was delivered today, so I also torqued the bolts that hold the HS-411 hinge bracket to the rear spar.  Referring to the chart in the Van’s manual, I am supposed to torque the AN3 bolts down to 20-25 inch pounds, adding in the torque required to turn the nylon lock nuts.  My beam wrench was showing 5-8 inch pounds required to turn the nylon nut on the AN3 bolt, so I figured I would torque the bolts down to a total of 28-30 inch pounds.  After torquing the nuts down, I marked them with an “X” using a sharpie.  I will apply some torque seal once it gets here. This way I know which bolts have been torqued.


Having completed that, I figured I should go ahead and dimple the right horizontal stabilizer skin, since I had a little bit of time left for the night. I used my DRDT-2 dimpler to do the work, and it went smoothly. I already had the dimpler set up from last nights work, so I just popped in the sets, and went at it.  I also remembered to mask off the holes in the skin that do not need dimpling, since they will be getting nut plates. The skin turned out well.


And for some reason, my camera decided to make a little video.  I must have flipped a switch somewhere, so for fun, here is the video my camera made for us:

I spent a few minutes tinkering around with the pressure settings on my rivet gun.  I will be riveting the ribs to the skins in a few sessions, so I want to make sure I have everything set right.  I think I might spend some more time on the practice kits doing flush rivets over again.  This will give me some more practice, as well as let me fine tune my rivet gun for the -3 flush rivets.

Here is a full photo album of tonights work: https://goo.gl/photos/upb27wsi3J5HnDuu5

Hours Worked: 1.25

Fixing the Bad Rivet in the Rear Spar

After reading some of the replies on what I should do about my messed up rivet, I decided to drill it out. I had some time to work on this before we head out to my parents house for thanksgiving, so I figured I would try to drill it out.

First I used a my noxon punch to dimple a point in the head of the rivet. The little center dimple from the factory was barely visible, so I used it to center my punch. Then I took a fresh #40 bit and slathered it in boelube and chucked it up. I put it in the center punched dimple, and turned it by hand a few times to get the bit started. Then I slowly drilled the head down deep enough I could break the head off with the butt end of an old drill bit.

Then I got a bit creative…. I didn’t have a receiving bar to drive the rivet into, so I ended up using a pair of vice grips. I stuck the jaws into a pair of leather gloves to keep from scratching the parts, and opened the jaws just enough so the rivet would fall into it. Then I used a punch and a small hammer to gently drive the old rivet out. My vise grips/glove worked pretty good as it received the rivet, and didn’t scratch my skins!

I checked the rivet and noticed that I had drilled perfectly center, and then checked the parts and the hole was undisturbed, so a regular rivet should work OK.

I stuck in a replacement normal rivet (AN470AD4-7) and squeezed it making sure I had my squeezer lined up and centered. It turned out great, and took about 30 minutes total time, since I was being cautious. I did end up scratching the nice paint on my bracket, I dropped the stupid punch as I pulled it away and the tip dug into the paint a little. Doesn’t appear to be anything than just paint, so I will hit it with some rattle can primer to seal it up against corrosion, and let it ride. Here is the end result, with a fresh rivet:

I also learned that the washer should go on the nut side of my HS-411PP and that I should torque it to roughly 25 inch/lbs. I ended up buying this torque wrench so that I can read what the torque is from the nylon lock nut, and then add that to my final torque value: http://amzn.to/2gl2Axd

Once the wrench gets here, I will torque down the AN3 bolts and apply some torque seal (also on the way). Here is the photos from what little work I did today: https://goo.gl/photos/kxhRmW3LXQTkWas9A

Hours Worked: .5

Riveting The Rear Spar

Tonight its time to rivet some parts together. The primer has been sitting a few days while I spent time with my wife and daughter these past few days, but I had some time tonight to work.

I started out by sorting my parts into the proper “piles”. Left / right horizontal stabilizer, vertical stabilizer, front / rear spar, etc. Then I picked up where I left off in the plans for the horizontal stabilizers. This section is the last one, titled “Riveting the horizontal stabilizer”.

I first started out by locating and taping up the holes for HS-706, HS-708 and HS-00005 as well as HS-412PP hinge brackets. These holes don’t get rivets just yet, so the tape will keep me from sticking one in there. Then I assembled the HS-609PP bars to the HS-603 rear spar channels, cleco’ing every other hole while ignoring the taped up holes.

Then I used AN470AD4-6 rivets to attach the bars to the spar. I used my squeezer to set these rivets. Once I got the first batch set, I removed the clecos and riveted the remainder. I did mess up on one rivet, and flinched the squeezer right as it compressed the rivet, causing it to mess up the manufactured head:

So, I figued now is as good as time as any to drill it out and fix it. I took my time, and used a #40 drill and slowly drilled the head off, then broke it off with a punch. The just used the punch to push out the shop head. The hole wasn’t damaged and it look good, so I stuck in a fresh rivet and re-squeezed it with great results:

Next up was to rivet on the hinge bracket, HS-412PP and HS-413PP to the rear spar. At first, when I inserted the rivet called for, AN470AD4-5, it seemed a little long, but a quick search of this forum returned that this is normal, and thats indeed the correct size. So I squeezed them with my squeezer and they turned out good.

Somehow I managed to damage the shop head on one of my HS-412PP hinge brackets. It has a small dent in the top of the shop head, and I am not sure if I should drill it out or if its OK as is. I am going to ask the forum to get advice. It’s easy enough to get to as-is, so I can drill it out with no troubles if need be. Here is what it looks like:

It looks like my squeezer set was offset a little on the shop head, and the lip bit into the rivet. We’ll see what everyone says is the best route to take.
Here is the link to the thread where I asked everyone: http://www.vansairforce.com/communit…20#post1129120

Next I pulled out the bolts, washers and nuts for the HS-411PP center bearing to bolt it to the spar. I have a decent craftsman torque wrench but I am not sure what torque to use. Nor am I sure which side the washer should go on, bolt head or nut side? So, I just fingered tightened them for now, and will ask the forum for advice.
Here is the link to the thread where I asked this question: http://www.vansairforce.com/communit…19#post1129119

So that was all I accomplished tonight. I have two “pending” items from this work session, that I am waiting on advice for.
1. Should I drill out that rivet in the hinge bracket
2. What torque do I need to use, and which way do the washers go for the HS-411PP center bearing.

Here is a link to tonights photos: https://goo.gl/photos/BGhzL2yD4LqPLxhD6

Hours Worked: 4